Post hole digger redesign

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Executive Summary

In order to further understand the overall design situation at hand, the team conducted a detailed research process involving usability studies, expert analysis, and market research. The usability studies conducted in the last report were expanded to involve a greater range of users to more thoroughly explore any areas for improvement. The team carefully chose the subjects - a male and a female - to test the simple and complex post hole diggers in a controlled environment on both hard and soft soil. It was found via the usability studies that both subjects preferred the complex design, which was contrary to our initial understanding that the simple post hole digger was more effective in digging holes. Despite the lack of mehcanical advantage, the subjects liked the complex design due to its ability to penetrate the ground and remove soil. In addition, subjects also mentioned key areas for improvement such as the hassle of bending over while digging and the possibility of customizing the post hole digger to suit various bodily demands. These findings were key in our development of conceptual designs. Once the usability studies have been collected and the findings documented, the team traveled to Home Depot, and specifically consulted with two experts who were highly experienced with the business of post hole digging. A key recommendation from the experts highlighted the issue of weight - while usually considered to be detrimental to the user experience and contributing to fatigue, weight was also critical in providing a strong penetrating force in the soil. It was advised that while weight reduction is crucial, it must not be overdone which will detract from the overall performance of the post hole digger. Similar to the recommendations of the subjects in our usability studies, the experts also stressed the importance of customizing the post hole digger to suit various bodily demands - more specifically, the prospect of implementing adjustable handles to suit users of various heights. Alongside conducting usability studies, the team conducted market research identifying current state-of-the art designs that are in the market, as well as reviewing past patents. The main products found were the simple post hole digger and complex post hole digger designs that were our main focus in Report 1, as well as 3 new designs. All of these designs were examined and the pros and cons of each were identified.

After reviewing the findings from the usability studies, expert analysis, and market research, the team met together to brainstorm potential ideas in creating conceptual designs. Ideas ranging from the surreal such as "trained gophers" to the more practical "adjustable handles" were proposed. After 100 ideas were proposed, the team then moved on to find the best and most realistic ideas that could be applied to our concepts.

Team members then collectively came up with 5 conceptual designs:
1. Telescoping handles design
2. Electric powered auger
3. Single handle ratcheting design
4. Ratcheting foot peg design
5. Single piece post hole digger

Upon developing the conceptual designs, the team understood that most of the research had been developed for the consumer side, and research had been difficult in consulting with experts on the manufacturing and assembly side. This understanding allowed the team to create the single piece post hole digger concept that focused on the needs of the manufacturers, as all stakeholders must be addressed when designing a quality product.

Our Pugh chart analysis of these designs versus the existing simple post hole digger showed that all 5 designs provided improvements, with the top two concepts being the ratcheting digging heads and single piece post hole diggers. These two designs address different stakeholder needs, where the single piece design improves the durability and manufacturability while the ratcheting digging heads emphasize usability and digging effectiveness. We request that the client review these two proposed recommendations and discuss with the design team on further pursuits with the design process.

Research and Observations

Design problem & insights/opportunities

The fundamental purpose of any post hole digger is to dig a deep, narrow. Most often, this is done in order to set a deck post, erect a fence, or fix some sort of structural column in the ground. While the speed and ease with which a gas powered auger can dig post holes may be appealing to some, the simplicity, cost efficiency and relative safety of a mechanical post hole digger is more than sufficient for most users and applications. Post hole diggers have come in many shapes, sizes, and have included numerous functionalities to improve the physical experience of using such a tool, but the room for improvement is still exists. Some of the areas of improvement, along with their corresponding design goals and a few potential remedies that have been identified throughout the design process for a mechanical post hole digger include:

  • Weight -- Optimize weight to reduce physical demand and still maintain robustness
    • Steel handles for robustness
    • Aluminum handles to reduce weight and maintain strength
    • One-handled design to reduce weight
    • Use of fiberglass in handles to reduce weight
  • Ground Penetration -- Increase the ability to penetrate the soil
    • Serrated digging head jaws
    • Use of foot for penetration rather than upper body strength
    • Ratcheting digging head mechanism which locks jaws open for penetration
  • Dirt Removal -- Increase removal capacity and still maintain ease of use
    • Ratcheting digging head closing mechanism which locks jaws shut
    • Serrated digging head jaws increase removal capacity by increasing penetration
    • Increase volume of digging heads
  • User Convenience -- Make the process as comfortable and easy as possible
    • Detachable carrying strap/Mechanism to keep handles closed when transporting
    • Spacer to prevent user from smashing hands together
    • Hole depth measurement device
    • Telescoping handles to adjust to user height
    • One-handled design
  • Manufacturability/Transportation -- Decrease manufacturing/transportation time and cost, optimize space usage
    • Product shipped to retailer in two halves, assembled in store when requested by customer
    • 3 part design - two halves, one pivot bolt/nut
    • Telescoping handles to increase portability
    • Quick disconnect between digging heads

These five areas of focus will help determine what the optimal post hole digger will look like, how it will work, and how much it will cost to produce and maintain throughout its life. The decisions made based off these design criteria will be crucial in deciding where the team's innovation is headed. This information, along with the results from user studies, expert analysis, and Pugh chart creation will ultimately define the new post hole digger in its entirety.

Usability Study

In order to get a better understanding of how the user interacts with our product, we conducted two usability studies. To broaden our knowledge on the use of the tool, we chose to examine two subjects -- one male and one female, both college aged. Each user study was conducted in the exact same manner. The user dug a total of 4 holes; 2 with the simple post hole digger and 2 with the complex post hole digger. Of the 2 holes dug with each tool, one was in hard, grassy soil, the other in soft topsoil. The user first dug for 5 minutes in hard, grassy soil using the simple post hole digger. He or she was then given a few minutes to rest, and moved on to digging another hole for 5 minutes with the complex post hole digger. This hole was strategically dug in an area nearby the previous one to maintain a common consistency of the soil. After another brief rest, he or she moved to the soft topsoil. The user dug with the simple tool until 5 minutes was up or a depth of 36” was reached, resting only after this milestone. Lastly, the subject dug in the soft topsoil with the complex digger for 5 minutes or until the 36” depth was reached. Again, the hole was dug near the first one made in the soft topsoil to ensure common soil consistency. Throughout all of the experiments the group members noted the user’s actions, comments, and depth of the hole throughout the process. After finishing the physical testing, the group asked the user to comment on the experience, while also asking specific questions to help prompt them for a particular type of response. A detailed rundown of each study can be found in the following paragraphs.

Study I: Average Female User

Name of Subject: Laurel Bancroft
Age: 21
Height: 5’ – 4”
Weight: 120 lbs.
Date: Friday, 9/26/08

Test 1: Simple post hole digger in hard, grassy soil

Observations made by group:
Fig. 2.1.2: Dirt falling from digger
Fig. 2.1.2: Dirt falling from digger
Fig. 2.1.1: 3" deep hole after 5 min. of digging
Fig. 2.1.1: 3" deep hole after 5 min. of digging

From the beginning of this test, it was immediately apparent that the soil was going to be quite difficult to dig. After encountering several rocks and a few roots, the user was only able to dig to a depth of 3" after the 5 minute time limit was reached. Throughout the entire experiment the subject struggled with actually removing the dirt from the hole. As the dirt continued to fall out of the shovel before removal, the user became visibly frustrated.

User comments:

Most of the comments made by the user during the test were fully expected, and helped solidify many initial thoughts and concerns we had with the simple post hole digger. Some of the issues she had with the tool included: banging her knuckles together, difficulty aiming and hitting the hole, fatigue from the weight of the digger, and the fact that the dirt failed to remain in the shovels during removal. She also mentioned that the misalignment of the handles annoyed her, and suggested the use of gloves with the tool.

Test 2: Complex post hole digger in hard, grassy soil

Observations made by group:
This test immediately showed the lack of mechanical advantage as the user struggled to even close the digging heads after penetrating the soil. The subject did do something fairly unexpected and quite interesting to make up for her lack of strength.
Fig. 2.1.3: User standing aside digger during use
Fig. 2.1.3: User standing aside digger during use
Fig. 2.1.4: User holding middle of handles
Fig. 2.1.4: User holding middle of handles
Rather than pulling the handles apart with both arms from a centered location, she stood to the side of the tool, pushing with one hand and pulling with the other. This phenomenon is depicted in Figure 2.1.3. On top of this, she also experimented on when to pull the handles apart. Rather than pulling the handles apart immediately and getting the tips of the digging heads stuck on the hard soil at the bottom of the hole, she pulled the whole tool up a bit before closing the digging heads. This allowed her to extract the loose soil in the hole without catching the shovel on the bottom. Another interesting technique employed by the subject occurred when entering the soil. When thrusting the tool downward into the ground, the she held the tool near the middle of its handles rather than the top where its grips are located. Once in the hole, she then moved her hands to the grips to pull the handles apart and extract the dirt. Figure 2.1.4 shows the user utilizing this tactic. Perhaps her experimentation paid off since the digging rate seemed higher for the complex post hole digger. During this test, the user reached 4" after just 3 minutes, ending up at 6" when time expired. She more or less doubled her digging rate with this tool.

User comments:

Again, most of the comments made by the user during the test were fully expected. Because she is fairly short, she struggled with the long handles, as demonstrated by Figure 2.1.4. She mentioned that the tool seemed heavier than the simple digger, and she became fatigued much more quickly. Besides these two complaints, her comments were generally positive. She appreciated the knuckle protecting mechanism, liked the sharper tips on the digging head, noting that it enabled her to pierce the ground more easily, and had less trouble aiming the tool in the hole. One bit of humor that arose from one of her comments came when she refused to kill a worm that appeared in the hole. She refused to continue until one of the members removed it.

General user comments prior to tests 3 and 4:

Before proceeding to the 3rd and 4th tests, we chose to ask the subject for a few general comments based off the performance of the two diggers in the hard, grassy soil. The user noted that if the simple shovel was aligned more accurately and had sharper tips, she’d rather use it because of its light weight. Her reasoning behind this was that she'd personally prefer to use a lighter tool and sacrifice the higher number of reps vs. using a heavier tool requiring fewer strokes. When asked if she had to dig a 6” hole in hard, grassy soil right now, she said she’d choose the complex digger, mostly because her digging rate was twice that of the simple digger.

Test 3: Simple post hole digger in soft topsoil

Observations made by group:
Fig. 2.1.5: Hole entry caved in
Fig. 2.1.5: Hole entry caved in
Fig. 2.1.6: Handles hitting edge of hole
Fig. 2.1.6: Handles hitting edge of hole

This particular test went much better than expected. Because the soil was quite loose at all depths, the subject was able to dig to a depth of 36" in just 4 minutes, well exceeding her performance in the hard, grassy soil. Despite this overall success, the test did show some negative results. Once a depth of about 16" was reached, the user began having issues aiming. After this point, she repeatedly hit the top edge of the hole, caving it in, stroke after stroke. Figure 2.1.5 shows how the entry to the hole became damaged as the user repeatedly struck it. Also, when the hole became roughly 24" deep, the handles of the digger began hitting the sides of the hole. This phenomenon is depicted in Figure 2.1.6. Throughout the entire experiment the subject struggled with actually removing the dirt from the hole. As the dirt continued to fall out of the shovel before removal, the user became visibly frustrated.

User comments:

As evidenced by her repeated failure to hit the hole, the subject admitted that she had trouble aiming as the hole became deeper. As a result of slowly caving the top of the hole in, she became timid with her penetrating thrust. She felt that if she slowed her self down a bit, she'd become more accurate. Once she did this, she did become much more accurate with her strokes. Besides these negative aspects, she repeatedly commented on how much simpler it was to dig in the soft soil. She was quite proud of her performance.

Test 4: Complex post hole digger in soft topsoil

Observations made by group:
Fig. 2.1.7: User standing aside digger during use
Fig. 2.1.7: User standing aside digger during use
Fig. 2.1.8: Handles clearing edge of hole
Fig. 2.1.8: Handles clearing edge of hole

Much like was the case with the simple digger, the complex digger performed much faster in the soft soil than it did in the hard, grassy soil. Because of its ability to scoop more dirt in one pass, the subject's digging rate was even faster than that of the simple digger in soft soil. After 1 minute, she had already reached a depth of 18". At this point, the user reverted to an old technique as discovered in test 1. She began standing aside the tool again, pushing with one hand and pulling with the other. Because the hole was much deeper, she added a slight twist in this technique by turning the hand with which she pushed, upside down. She can be seen doing this in Figure 2.1.7. As the hole became deeper, it became obvious that the increased length of the complex digger compared to that of the simple digger was becoming a problem. She eventually dug by initially grabbing the handles on the grips to get the dirt half way up the hole, but because she was too short to get the entire tool out she tried moving her grip down to the middle of the handles to extract the dirt. This technique often failed, causing a good portion of it to fall out of the shovel. One result worth noting was that, at a depth of 36", the handles of the complex digger came close to, but did not touch the edge of the hole (see Figure 2.1.8). This was interesting to us, because when purchasing the tool this phenomenon was one of its main points of advantage that it claimed over other designs.

User comments:

While the subject was, again, quite proud of her rapid performance, she did admit that the increased scoop capacity of the complex post hole digger made her tired very quickly. She noted that it seemed very heavy and made her back somewhat sore during use. The subject also recognized that her short stature made it very difficult to dig as the hole deepened. She also complained that bending over to finish the whole made her legs and back sore.

General user comments following all 4 tests:

Upon completion of all the tests, we chose to ask the subject for a few more general comments regarding the performance of the two diggers. She claimed that the simple digger was much easier to pull apart than the complex version, but its construction seemed to be lacking. Its poor alignment was annoying, and the wood handles seemed as if they could easily splinter or break. Some complaints she had regarding the complex digger included the length of the handles being too long, and the difficulty she had pulling the handles apart when compared to the simple version. A complaint common to both models was that the diameters of the handles were a little too large, causing her hands to hurt after performing each test. When asked if she had to dig a 36” hole in soft soil, she would've preferred using the simple tool, mainly for its light weight. When asked which tool she would choose in a store and why, she said she would’ve chosen the complex digger for the following reasons:

·The sharp tips allow you to get better penetration
·She would’ve assumed they were both the same weight even though the complex tool was quite a bit larger. This :was because it seemed to her like it was made of more high-tech material, meaning it wouldn’t have weighed any :more than the simple digger.
·Since the complex tool was twice as expensive, she would have assumed that expense meant a better product

When the idea of using a gas powered auger was proposed, she said just not knowing how to use one would completely deter her from using it, plus the danger involved was not appealing. She would have gone with one of the mechanical versions instead.

Study II: Average Male User

Name of Subject: Ryan Chehanske
Age: 20
Height: 6’ – 0”
Weight: 240 lbs.
Date: Monday, 9/29/08

Test 1: Simple post hole digger in hard, grassy soil

Observations made by group:
Fig. 2.1.10: User gripping both handles together
Fig. 2.1.10: User gripping both handles together
Fig. 2.1.9: Rocky, root ridden soil
Fig. 2.1.9: Rocky, root ridden soil

As expected, the increased size and strength of the subject provided some fairly different results. Again, the soil was quite rocky and contained roots, but the user overcame these obstacles fairly well. The poor soil conditions are depicted in Figure 2.1.9. After just 2 minutes of digging, he had already eclipsed the female subject's hole depth and had reached 5". Despite this early success, his performance waned, allowing him to reach a depth of only 7" at the 5 minute time limit. One technique used by this subject that differed from the female user was his penetration thrust. When preparing to thrust the tool into the ground, rather than gripping each handle individually, the user was closing the tool and wrapping both hands around the two handles simultaneously. He can be seen doing this in Figure 2.1.10. Much like the female user, throughout the entire experiment the subject struggled with removing the dirt from the hole. As the dirt continued to fall out of the shovel before removal, this user became even more visibly frustrated.

User comments:

Most of the comments made by the user during this test were aligned with those of the female subject. He complained about the tool's misalignment, claimed his hands were hurting afterwards, and was extremely annoyed by the dirt continually falling from the shovels. When asked how difficult it was to aim the tool and hit the hole, he said it was not an issue.

Test 2: Complex post hole digger in hard, grassy soil

Observations made by group:
Fig. 2.1.11: User flipping hands during removal
Fig. 2.1.11: User flipping hands during removal
Fig. 2.1.12: 10" hole in 5 minutes
Fig. 2.1.12: 10" hole in 5 minutes

One of the interesting results of this particular experiment involved the subject utilizing an unexpected technique when pulling the handles apart. Rather than pulling apart with both palms grasping the outer edges of the handles, he rolled his wrists over, holding the inside of the handles instead (see Figure 2.1.11). Besides this observation, the only other noticeable thing was his speed. After 2 minutes he'd already dug 6" of dirt, and when the 5 minutes was finally up he'd reached a depth of 10", as shown in Figure 2.1.12. Again, this was nearly twice as deep as the corresponding test for the female user.

User comments:

The male subject immediately noticed how much more difficult it was to pull the complex digger's handles apart, making note that this was the most difficult part of using the tool. One particular complaint he had dealt with the tool's initial alignment. Because of the knuckle protector the handles are spread apart somewhat before entering the ground, making it penetration a different process biologically. The user complained that because of this, he was forced to use his forearms more than before, exhausting them relatively quickly. The subject also pointed out that the handles seemed to deflect a lot more than those of the simple digger. When asked about the weight and aiming of the tool, he said both were not a problem at all. The user did recognize that this particular tool digs a larger diameter hole, and its edges were quite a bit cleaner. He pointed out how nice it was that this tools digging heads completely seal the dirt in when trying to extract it -- one of the positive observations made repeatedly by both users.

General user comments prior to tests 3 and 4:

The only comment the user had before proceeding to the soft soil was that he'd much rather prefer to use the complex post hole digger at this point.

Test 3: Simple post hole digger in soft topsoil

Observations made by group:
Fig. 2.1.13: User bending over
Fig. 2.1.13: User bending over
Fig. 2.1.14: Handles hitting edge of hole
Fig. 2.1.14: Handles hitting edge of hole

After experiencing how much easier it was for the female user to dig in the soft topsoil, we had high expectations for the male subject for this test. He definitely performed as expected, making quick work of the hole. The subject was able to dig to a depth of 27" in just 1 minute, quickly surpassing the female user's performance in the her respective test. He eventually reached the 36" mark after just 2 minutes of digging. Despite this overall success, the test did reveal some negative results. Once a depth of about 24" was reached, the user began having issues with having to bend over. Figure 2.1.13 demonstrates how far the user had to bend over when removing the dirt. Another observation made was that the wet soil near the bottom of the hole stuck to the digging heads quite a bit, forcing the user to tap the tool's tip on the ground beside him to remove it. Once the hole was near its final depth, it became obvious that the tool's handles were restricted by the hole's edge, as seen in Figure 2.1.14. This agrees with the corresponding test performed by the female subject.

User comments:

Overwhelmed with how soft and light the soil was, the user couldn't stop commenting on how much easier it was to dig in the "soft stuff". The user also verified one of our observations, complaining about the length of the handles. Because they are fairly short, he had to bend over when the hole deepened. He mentioned that it wouldn't have been enough to bother him in just 2 minutes of digging, but if he was working all day, it would have been much more problematic.

Test 4: Complex post hole digger in soft topsoil

Observations made by group:
Fig. 2.1.15: User flipping hands during removal
Fig. 2.1.15: User flipping hands during removal
Fig. 2.1.16: Deflection of handles
Fig. 2.1.16: Deflection of handles

As established before, it was apparent immediately that the complex tool was able to get much more dirt with one scoop. It seemed as if this may have made him tired quickly, because it took him 3 minutes to finish the hole, whereas with the simple digger, it only required 2 minutes. One interesting thing the user did during this study was the use of two piles for dumping the dirt. We weren't quite sure why he did it, but it definitely made cleanup a little more difficult when he finished digging. It seemed as if the inverted handle grip technique was a staple for the male user, as he can be seen doing it again in Figure 2.1.15. Another interesting observation was the extreme deflection of the fiberglass handles. This phenomenon can be seen in Figure 2.1.16. Other observations made that mirrored those of previous tests included: dirt sticking to the shovel heads, the handles not touching the edge of the hole upon completion, and the use of the technique of standing aside the tool during use, pushing one handle and pulling the other, rather than pulling both from a centered stance.

User comments:

The user repeated noticing that the handles of this digger weren't fully together when beginning his downward thrust (due to the knuckle protector piece). Because of this, it made it hard for him to pull the handles apart at the bottom of the hole – it seemed like there wasn't enough room to open them. He added that he would've strongly preferred that the handles be closer together initially. The user also commented about the complex digger's increased scoop capacity. Because you can get so much more dirt with one scoop, it made the tool fairly heavy, making the work seem a bit harder than when using the simple digger. Again, he complained about how difficult it was to pull the digger's handles apart, suggesting that we lube them up next time.

General user comments following all 4 tests:

One major observation that the male subject pointed out, was that it seems like no matter which tool you use and what type of soil you’re digging in, most of the work is done within the first 60 seconds or so. After that point, it's as if you’re just meticulously picking away at the dirt and getting nowhere. The user praised the complex digger for it's ability to pierce the ground and seal the dirt in upon removal, but mentioned that it was much more physically demanding to use than the simple digger. When asked which tool he’d choose if he had to dig a 36” hole in hard soil right now, he said he would much rather use the complex digger because this tool has sharper digging heads to penetrate the soil and it seals the dirt in better when clamped shut. On the contrary, when asked which tool he would choose if he had to dig a 36” hole in soft soil right now, he said he would much rather use the simple digger. He liked the fact that this tool’s handles are closer together. He added that if the simple digger had sharper tips, could somehow seal the dirt in the digging heads, and had a more efficient scoop capacity, he would choose it over the complex design. With long term use, this user felt that the complex digger would break first. Either one of the bolted connections would break or come loose, or the handle would break. His reasoning for this was that it seemed like the handles were deflecting quite a bit when using it. When asked which tool he would choose in a store and why, he said he would’ve chosen the complex digger for the following reasons:

·The sharp tips allow you to get better penetration
·You get more bite with one thrust
·The grips on the handles are nice
·The complex digger looks beefier and nicer, and is more attractive

When the idea of using a gas powered auger was brought up, the user had the following to say: "If I had to dig 20 holes in a day, I’d definitely use a gas powered auger. The benefits of its speed and ease would far outweigh the risks and expense involved with using an auger. On the other hand, if I had to dig, say, 4 holes in a day, I’d use the complex digger. It’d be more practical than the auger, relatively cheap, and just makes more sense."

Usability Study Conclusions

The bulleted list below highlights the major findings resulting from the two user studies performed by the group. More detail on the differences between the designs and how they were received by the user can be found with a closer look at the Usability Study section of the report. These basic conclusions, along with the expert analysis results will help drive the group towards a final decision on a design concept.

  • User related conclusions
    • User strength affects the ability to aim the tool
    • User height affects one's ability to use the complex digger
    • Bending over is annoying
    • Average male user digs about twice as fast as his female counterpart
  • Simple design conclusions
    • Misalignment of the simple tool is fairly annoying
    • The simple tool is much easier to use, especially when pulling the handles apart
  • Complex design conclusions
    • The sharp teeth of the complex digger's shovels are nice for penetration
    • The complex tool's ability to seal the dirt in is a strong advantage
    • The increased scoop capacity of the complex digger makes the user tired quickly
    • The complex tool's claim for digging deeper holes seems relevant and justified
  • General conclusions
    • Soil quality plays a huge role in digging rate
    • Looks play a role when purchasing a post hole digger in a store
    • Most of the work is done in the first few minutes, then the soil becomes very hard

Expert Analysis

In order to gain further insight into the usability of our product and possible areas of improvement, we talked to two experts who have used post hole diggers for a significant period of time. Both of these experts gave similar recommendations as to how the product could be improved. We met the two experts during a trip to Home Depot in East Liberty, on Sunday, September 28th, 2008. Both experts provided useful insight on how the product is used and can be improved, which are summarized below.

Expert 1 Expert 2
Name James Andrea
Age ~45 years old ~55 years old
  • Average height and build
  • Has used diggers since early childhood
  • Shorter female user
  • Has lived on farm entire life, so has much experience digging holes

We asked each expert to describe their process of using the tool, and somewhat unsurprisingly, got answers that were quite similar to what we came across in our own experience of using the products. However, both were able to provide excellent feedback on desired changes or redesigns to a post hole digger. Below, the main improvements that they recommended are presented.

Improvement Reasons Notes
Improved digging heads
  • Need pointed or seraded edges to better penetrate ground
  • Require better head design such that heads can close without losing dirt
  • Both experts expressed frustration with the design of the current heads, important as the heads are vital to an efficient post hole digger
  • Both users reiterated these desires, and both became particularly frustrated by the inability of the simple digger to extract dirt from holes
Telescoping Handles
  • Would allow for use with users of different heights and sizes
  • Can be used at any point in the digging process
  • Both experts and users expressed frustration with using the diggers. Unless the user is taller than 6ft, both tools can be difficult to use, especially at the beginning
  • Could also be of assistance as hole becomes deeper to prevent bending over
Knuckle Bar
  • Prevents user from cracking knuckles when closing handles
  • Desired on both diggers, although currently only present on complex digger
  • Could be packaged as a stand alone addition to existing diggers
Compact Digging Head Closing Mechanism
  • Many problems associated with the mechanism used to close the digging head on both current designs
  • In addition to being difficult and unnatural, requires significant force to be applied
  • A ratcheting or single pole design would be more complex but improve upon many common complaints, including difficulty associated with closing heads while in deep holes
  • As it stands, hard for user to open and close heads while deep in a hole
  • Current lifting motion required to remove dirt is very unnatural and leads to a lot of dirt spilling back into the hole

Both experts also presented us with a variety of observations from their use with post hole diggers over the years. Both recommended against using augers unless absolutely necessary, due not just to their high cost and environmental damage, but to the difficulty in using them and the possibility of injury when using powered augers. Also, due to the difficulty in penetrating hard soil, both experts would often wait until after it had rained to dig holes. However, this method would usually only help in the initial foot of digging. Regardless of whether or not this was done, both found that handles were likely to break or give the user splinters. Soft soil can also present challenges when digging holes, as the user has to be careful to prevent the hole from collapsing. Finally, both recommend the use of a tamping bar to deal with rock, especially given the abundance of flagstone in and around the Pittsburgh area.

We talked with a third expert, Paul Clinkard, of Toronto, Canada. Although a carpenter by trade, Mr. Clinkard spends a considerable amount of time working with contractors and landscaping companies. As a result, he has accumulated a great amount of experience with post hole diggers, both through his own use and his interactions with professional landscapers. Mr. Clinkard provided us with a great deal of feedback that was in general in agreement with that from our user studies and other expert analysis. However, Mr. Clinkard was able to give us information about not just the occasional user, but the professional landscaper or contractor who would dig hundreds of holes a year.

Like our users, Mr. Clinkard found dirt removal to be a considerable issue with any type of post hole digger, and preferred a simple design that held dirt in its digging heads. He also noted the issue of durability as being a prime reason why simple diggers tend to be much more popular with landscapers than their more complex counterparts. He had personally used several simple diggers that featured lightweight aluminum handles in the place of their standard wood counterparts, and noticed a considerable reduction in fatigue and an increase in speed. These handles were not standard, but add ons designed and installed by the user. Similarly, Mr. Clinkard noted that speed and efficiency is an important issue to contractors, and found that almost all would be willing to purchase a more expensive digger if it gave noticeable results in terms of digging rate. Like the other experts, Mr. Clinkard noted a strong aversion to using a gas powered auger, listing them as a last resort. They can be extremely dangerous in an urban environment when one has to deal with buried wires, and also tend to do a fair amount of damage to the surrounding area, an effect that is highly undesirable in landscaping. Mr. Clinkard's feedback has proved to be extremely valuable in helping us to identify a new market segment that was previously not fully understood by us.

Updated Stakeholder Needs

Following the usability studies in addition to consulting with experts and the professor, the stakeholder needs identified previously in Report 1 are updated for a more comprehensive outlook.

The primary consumers for the post hole digger involve homeowners, construction workers, landscapers, and other users that are primarily focused on digging deep, uniform holes to erect fence and deck posts.

  • Product must be relatively cheap to purchase (most state-of-the-art models within $20-$40 range)
  • Design needs to be relatively lightweight to prevent fatigue
  • Durability is very important, most current designs have lifetime warranties
  • Design needs to be able to adapt to a range of users with different body types
  • Post hole digger must be effective at grasping soil for both hard and soft soils
  • Post hole digger must also be able to penetrate deep into the soil for leverage
  • Must be simple to carry without injury
  • Must be safe to operate without any major bodily injury, direct or indirect

The primary retailers are identified as parties selling the actual product to the users, mainly home improvement centers and hardware stores such as Lowes and Home Depot.

  • Product footprint must be small for efficient storage
  • Design must be of manageable weight to be able to be readily accessible in stores
  • If shipped in parts, design must be easy to reassemble when arrived at retailers
  • Post hole digger must be aesthetically pleasing such that it will not detract from the store environment as well as attract customers

Manufacturers are primarily focused on processing raw materials into the necessary parts encompassing the post hole digger, as well as assembling these parts to the finished product.

  • Product must have interchangeable parts for efficient manufacturing
  • Product must have relatively low part count to minimize excess processes to reduce costs
  • Materials utilized must be relatively easy to process, such as steel, aluminum, or wood
  • Processes used must be relatively cheap to conduct, such as stamping
  • Post hole digger must have parts that are simple and straightforward to assemble and do not require specialized skills to reduce labor costs

The primary shipping/transport stakeholders involve commercial delivery companies that deliver the products from manufacturers to retailers. The most common form of transportation involve trucking that transport each prodcut from central factories to specific distribution channels.

  • Product must be lightweight to reduce energy costs in transportation (gas consumption), as well as minimize loading/unloading time
  • Product footprint must be small for efficient packing to maximize load capacity
  • Design must durable such that product will not be damaged during transportation

Market Research and Current State of the Art Designs

In addition to consulting with experts and usability studies, we conducted research to identify the current state-of-the-art designs in the market, as well as existing patents and prior designs that have been conceived to improve the post hole digger. By examining various patents and existing alternatives, we can identify the strengths and weaknesses of each design as well as creating a design that does not infringe any existing copyright laws.

Current Major Models and Designs

Standard Post Hole Digger

The most common design for the post hole digger consists of a pair of simple wooden handles bolted onto two identical stamped steel shovel blades. These blades are connected via a single bolt with a sleeve that protects the bolt from soil and other foreign objects encountered during use. This design is identical to the simple post hole digger purchased and analyzed in Report 1, where the handles are pulled apart in a side-to-side motion while digging. This is a relatively sturdy design that utilizes the mechanical advantage of the pivot point to ampify the force applied by the user on the handles. For a more detailed analysis please consult Report 1.

Pros: Durable, high gripping force
Cons: Heavy, rounded shovel blades do not penetrate soil effectively, awkward to carry, no protection for knuckles

Complex Post Hole Digger

The complex post hole digger is a slight upgrade from the standard post hole digger, and is the other design in focus highlighted in our usability studies and in Report 1. This design utilizes an additional linkage that causes a compound action that reduces the distanced needed to pull apart the handles during operation. The design also has an additional add-on embedded between the handles to prevent the users from hitting their knuckles while digging. For a more detailed analysis on this design, please consult Report 1.

Pros: Durable, protection for knuckles, minimial pulling distance needed to grasp soil, sharp shovel blades to improve soil penetration ability
Cons: Heavy, loss of mechanical advantage from multiple pivot points, awkward to carry

Split Handle Post Hole Digger
Similar to the common post hole digger, this desing utilizes a pair of simple wooden handles bolted onto two identical stamped steel shovel blades. However, the main difference is that the handles are aligned such that to operate the split handle post hole digger, the handles are pushed apart in a front-to-back motion, similar to the motion of drawing a bowstring in archery. This difference provides an alternative to the standard operation method of pulling in a side-to-side manner. This design is most commonly manufactured under the Osh Kosh Tools brand.

Pros: Durable, high gripping force, an alternative operating motion
Cons: Heavy, dull shovel blades similar do not penetrate soil effectively, awkward to carry, no protection for knuckles

Erie Hole Digger ("Boston Digger")
Image:Post_hole_digger_state_of_the_art_4.jpg Image:Post_hole_digger_state_of_the_art_4b.jpg
This unconventional design is designed and manufactured by Sinclair Erie Ltd, and utilizes a single handle design attached to a single shovel blade. An additional scoop is bolted to the shovel blade and connected to a lever that allows the scoop to open and close against the shovel head. This user operates this design by initially thrusting the digger into the soil. Once the shovel blade is embedded into the ground, the lever is pulled, causing the scoop to close with the shovel blade, grasping the soil as the digger is pulled out of the ground. This design comes close to a single handle design, but is not considered entirely a single handled design as the lever itself is rather large and resembles an additional handle. While innovative, this the durability of the design comes into question as there are an increased number of moving parts exposed under operation. The racheting digging heads conceptual design proposed in the following section is a similar design that is created to improve the durability and performance of a single handle post hole digger.

Pros: Reduced motion in operation, lower weight
Cons: Increase in moving parts, durability issues, complicated operating procedure.

Fiskars All-Metal Post Hole Digger
Aside from the rubber handles, the entire design of the Fiskars patented post hole digger is made of steel. In essence, the handles are welded to the shovel blades to create a very resilient design with minimal parts. Connections are also minimized in that there is a specially-designed 2 -part joint that runs between the two shove blades for the main pivot. In addition, the narrow design also reduces the overall motion required to open and close the shovel blades. This design reduces the amount of assembly time and cost, but does include a complicated manufacturing step in welding. The Fiskars post hole digger provided the inspiration of creating a single piece conceptual design that focused more on manufacturabilty and assembly that is examined in the following section.
Pros: Low part count, durable, easy assembly, reduced motion in operation
Cons: Heavy weight, welding may pose a manufacturing problem, awkward to carry

Existing Patents

Blade upgrade for post hole digger
This is a simple design that upgrades the current dull edges of the simple post hole digger with jagged teeth. This design strives to improve the thrusting effectiveness of the post hole digger. Our design adopts a similar concept in that all of our conceptual shovel blades sport a pointed design to improve soil penetration.

Mini hand powered tube auger
This patent addresses a very unorthodox design. It encompasses a hollow tube with jagged edges on one side. The tube is attached with handles opposite the jagged edges and operated by rotating the handles when the design is placed vertically on the ground. The jagged edges will dig into the soil as the handles are rotated, and once the desired depth is attained, the mechanism is pulled from the ground and the soil emptied. We found this design to be really odd and beleive that it will take much longer to dig a conventional hole using this method due to the sheer number of rotations needed to be made to dig a sufficiently deep hole for a post.

Advanced complex post hole digger
This patent takes the complex post hole digger design mentioned in Report 1 a step further. Rather than using an additional joint, multiple joints and handles are attached. We found this design to be overcomplicated, as the sheet number of moving parts would provide difficult to use as well as increasingly heavy.

Post add-on
This innovative design focuses more on the post implanting process rather than digging the hole itself. Essentially it is an add-on that is attached to the bottom of the post being installed that provides a sharp boring section that can be pounded/screwed into the ground. This design also includes a mechanism that allows a garden hose to be attached, in the idea that the garden hose will loosen the soil with water as the post is being pounded into the ground. The main problem with this design is that multiple add-ons will have to be purchased. More specifically, for every post the user must buy an add-on, which can amount to very high costs if there are a large number of posts needed to be installed.

Impact post hole digger
This design utilizes an adjustable foot peg that allows the user to apply body weight in addition to the standard pushing forces used to penetrate the ground. More intriguing is the flat striking plate at the top of the digger that allows the user to strike the post hole digger with a sledgehammer, further increasing the penetration force. The concept of adjustable foot pegs were adapted in one of our conceptual designs, as we feel that it may be a great asset in improving the effectiveness of a post hole digger. We found that the idea of striking the post hole digger may pose issues in terms of long term durability.

Single handle central pole digger
This single handle post hole digger adopts a central pole that runs inside the handle. The central pole is linked to the shovel blades, and the user operates the poste hole digger by pushing down and pull up on the central pole. By pushing down, the links attached to the pole will push outwards against the shovel blades, causing the blades to open. By pulling up, the opposite effect happens where the links will pull inwards, effectively closing the shovel blades to trap soil.

Fiskars all-metal post hole digger
This is the official patent submitted on behalf of Fiskars for their all-metal post hole digger. A more detailed description is mentioned in the section above. This design inspired the conceptual design of a single-piece post hole digger geared towards manufacturing, assembly, and transportation efficiency.

Design Concepts

Through our extensive research and user studies, we identified several problem areas with the post hole diggers and potential opportunity for improvement in these areas. This led to the development of a large number of possible solutions that were developed through several brainstorming sessions. A list of the ideas generated from brainstorming can be seen in the appendix of this report. The large list of new ideas was eventually narrowed into five concept designs based on the previously identified areas of improvement. These five concepts, along with a list of generic improvements to be included in all designs, are presented below.

Concepts to be Implemented in All Designs

Based on our user research and market studies, there are several improvements that we plan to implement into all of our design concepts, since the ideas are simple and can be applied across a broad range of tool designs.

  • Sharp Digging Heads
    • Our studies show that the pointed digging heads of the complex digger are much more effective at penetrating the ground than the rounded digging heads of the simple digger. The sharp digging head can easily be implemented into new designs, since all that is required is changing the shape of the digging head blank to have a pointed tip.
  • Knuckle Protector/Handle Spacer
    • The handle spacer is another concept that is already implemented in the complex digger. It prevents the handles from closing to far and prevents the user from smashing his or her knuckles together. This spacer is very easy to implement on all designs, since it is simply a small bracket that can be attached to one handle.
  • Measurement Markings on Tool Handle
    • Post holes are often required to be dug to a certain depth, and separate measuring tools must be used to gauge the depth of the hole. By painting or applying a sticker with a graduated scale on the tool handle, the user can easily judge the depth of the hole without needing a secondary measuring device.
  • Removable Carrying Strap
    • Post hole diggers are heavy objects, and due to their large shape, are difficult to carry over long distances. Also, when carrying the tool, both handles must be gripped some fashion as to keep the handles together, otherwise the tool opens up and becomes very awkward to carry. A removable carrying strap would solve these problems. It would bind both handles together, and also allow the user to sling the tool over his or her shoulder, making the carrying process easier. Since it is removable, it would not interfere with the process of digging holes.

Concept 1: Telescoping Handles

Figure 3.2.1:Illustration of Concept 1, showing the application of telescoping handles
Figure 3.2.1:Illustration of Concept 1, showing the application of telescoping handles

This concept deals with a problem encountered by many users when using a post hole digger: the tool is simply too large to use. For any user shorter than 6 feet tall, the tool is very awkward to use as the handles are located at or above their head. This results in the user grabbing and using the tool in many non-ideal locations, reducing its effectiveness (due to a lower mechanical advantage) and also increasing the probability of injury through misuse. This is of particular concern in the case of the complex design; here, the user was forced to grab the fiberglass section of the handles, increasing the possibility of dangerous fiberglass splinters. With the addition of telescoping handles, the user would always be able to place their hands on the handles. Further, a better digging head design could be used to help with dirt removal and penetration.

The issue of handle length became an issue again when the hole became deep, as the user was forced to bend over to remove the digger from the hole. This issue can be solved through the use of telescoping handles. This simple addition would allow a wide range of height adjustment for the handles, making use of the digger much easier for smaller users. There are a number of possibilities for incorporating a telescoping mechanism; the most simple one is shown in the accompanying illustration. Here, the handles can be rotated to unlock the telescoping action, and then rotated in the opposite direction when the desired height is reached. However, other mechanisms are by all means being considered. One possible drawback of this concept is the reduction in strength that it creates, although this should not be an issue if the proper materials are used.

Concept 2: Electric Auger

Figure 3.3.1:Illustration of Concept 2, an electric auger
Figure 3.3.1:Illustration of Concept 2, an electric auger

In our usability studies, we noticed that many of the users would become fatigued after only several minutes of operation. This resulted in a significant decrease in the rate at which dirt was removed from the hole. In order to combat this problem, we decided to utilize electricity as a means of assistance when using the digger. In order to accomplish this, it is necessary to change to an auger type of post hole digger. The resulting design concept significantly reduces the amount of fatigue encountered by the user during use. It should be noted that the strength of the user would often also become an issue, especially in the case of the complex digger; with an electric auger, this would no longer be a problem. The use of a variable speed motor also gives the user greater control over the depth and rate at which a hole is dug. However, problems could possibly be encountered in extremely hard soil; furthermore, the length of the auger limits the depth of the hole to an extent.

We also considered the safety issues and usability expressed by many when attempting to use a gas powered auger. Many encounter difficulties when the auger hits a rock or root, and torques significantly. However, this can be addressed by the addition of a simple clutch mechanism in the electric motor. Much like in an electric dirll, its sensitivity could be changed to allow for the different soil types encountered when digging a post hole. To prevent the user from getting sprayed with dirt and debris, a simple shield can be added to the base of the digger; as the hole gets deeper, this can simply be moved further up the digging shaft. Problems could also be encountered with manufacturing and an increased cost to the user. However, such a design gives the additional benefit of allowing holes of greater depth to be dug more easily, as the requirements for the width of the hole are not an issue.

Concept 3: Ratcheting Digging Heads

Figure 3.4.1:Illustration of Concept 3, showing the application of a ratcheting digging mechanism
Figure 3.4.1:Illustration of Concept 3, showing the application of a ratcheting digging mechanism

One common complaint with both post hole diggers was the difficulty in removing dirt from the hole once penetration had been made. This was not simply due to the poor clamping ability of the digging heads on some models, but also problems encountered in hole size when the hole got deeper and the difficulty in closing the digging heads themselves. Further problems were noted in the movement required when removing dirt from the hole; in most cases, the user is required to lift the weight when their hands are far apart, rather than being able to lift directly up with the dirt in the shovel; often, a significant amount of dirt was lost here.

A simple method of solving these problems is to design a post hole digger with a ratcheting digging head. This concept is able to solve these issues by moving the closing mechanism to the handle. The user is able to squeeze a lever that closes the digging heads and locks them in place. This portion of the mechanism can be designed in order to give the user a greater mechanical advantage to reduce fatigue. When the digger is out of the hole, the user can simply press a release button to deposit the dirt in its desired location. This concept also allows for a single shaft digger whose parts are always contained inside of the digging heads; this prevents the width of the hole from becoming a problem when closing the digging heads as the hole gets deeper. Also, the removal of the dirt from the hole is in a much more natural, less stressful motion that allows the user to increase their efficiency. However, this mechanism will increase the complexity of the digger, which can effect its overall durability if not implemented properly, in addition to its price.

Concept 4: Ratcheting Foot Peg

Figure 3.5.1:Illustration of Concept 4, showing the application of an adjustable foot peg
Figure 3.5.1:Illustration of Concept 4, showing the application of an adjustable foot peg

One important finding in our usability study revealed that after digging several inches into hard soil, it became increasingly difficult to penetrate into the hard soil, even with the sharp digging heads of the complex post hole digger. To address this issue, the design team developed a concept of having an adjustable foot peg or pegs built into the post hole digger handles. With these foot pegs, the user could use the weight of his or her body to force the digging heads into the ground, much like digging with a spade shovel. The foot pegs need to be adjustable in their position, otherwise the hole digging depth would be limited.

The idea of an adjustable foot peg can be seen in several patents, but these designs use a clamping system with a nut that must be tightened, or a design that requires inserting a pin into holes in the handle to secure the foot peg (much like the method used to adjust the amount of weight on a weight lifting machine). These sorts of designs are cumbersome and take an excessive amount of time to adjust . Our design simplifies the foot peg idea into an easily adjustable system. A ratchet-style rack is attached to the handle of the post hole digger. The foot peg has a hole which allows it to fit over the handle and the rack, as well as a tooth that engages the rack. The hole that encompasses the handle and rack is large enough that tilting the foot peg upwards disengages the tooth from the rack and allows for quick adjustment up or down. Rotating the foot peg back re-engages the tooth, then the user can apply a force with his or her foot.

The manufacturing of this design would not be a complicated process, as the rack and foot peg components could be easily added on to existing standard designs. Of course, with the additional components, the cost of manufacturing and assembly time would be increased. The transportation of the product would not be affected, because the this concept has practically the same foot print as the standard design. With the additional parts, the user would see an increase in cost, but this cost would be considered reasonable given the rather useful feature added to the product.

Concept 5: Single piece design

Figure 3.6.1:Illustration of Concept 5, showing the single piece of stamped sheet metal design
Figure 3.6.1:Illustration of Concept 5, showing the single piece of stamped sheet metal design

While the previous concepts have focused on the primary stakeholder needs (the customer), this design focuses on the needs of the manufacturer and transporter. The concept is that of a single piece design: combine the digging head and handle into one part, made from one material. Join two of these parts together with a bolt and a nut, and the result is a post hole digger made from 4 parts. As seen in Figure 3.6.1, the digger half is made from a single piece of stamped sheet metal. With the design open on one side the sheet metal being bent in such a way as to taper out towards the open side, the halves could be stacked one inside the other.

With this concept, the post hole digger is not assembled by the manufacturer, but rather by the retailer. Having the retailer perform the assembly takes advantage of the stacking ability of the design. Being able to stack the parts reduces the footprint of the product in shipping; multiple diggers can take up the space that would be traditionally taken up by one standard digger.

The single piece design should significantly reduce manufacturing costs. All the manufacturer needs is the infrastructure required to stamp sheet metal. The capital cost would be higher since large presses would be needed to blank and bend the tool (which is approximately 5 feet in length), but the material costs would be low and the production rates very high. The tool would require protective painting as well, but this is also a simple process for the manufacturer to implement.

There could be some potential issues with this concept since it does not address customer needs. The open-sided design creates a non-ideal surface for gripping the tool, which may cause excess discomfort to the user. Also, aside from having sharper digging heads, this design offers nothing more to the user than the simple post hole digger currently does.

Pugh Chart

A Pugh Chart is a tool used to compare designs in a systematic way. A set of criteria based on customer and stakeholder needs is generated, and each of these criteria given a weighting. In the Pugh Chart below, the weighting scale runs from 1 to 5, with 5 being the highest. Each design is compared to a datum (in this case, the simple post hole digger), and rated with a - if the design is worse than the datum, 0 if the design offers no improvement over the datum, and + if the design is offers and improvement over the datum. Multiple positives and negatives can be given in ranking if a design excels in some criteria or is rather deficient in some criteria. The amount of positives and negatives is multiplied by the weighting factor, and the numbers added together for a final net score. The net score can then be used to evaluate how well a design meets stakeholder needs, the strengths and weaknesses of a design, and where the potential exists to combine the best features of different design concepts. Our Pugh chart reveals that the Single piece design scores the highest with a net score of 20, with the One handled ratcheting design scoring the second highest with a net score of 9.

Description Simple Post Hole Digger Complex Post Hole Digger Telescoping Handles Electric Pole Mounted Auger One Handled Ratcheting Digging Head Ratcheting Foot Peg Single Piece Design
Criteria Weight Datum Alt. Design Design 1 Design 2 Design 3 Design 4 Design 5
Cost 40-------+
Safety 200+--0-0
Durability 40+---0+
Ease of Use 40-+++++0
Ability to penetrate soil 40++++++++
Ability to remove dirt 50+0+++00
Manufacture/Assembly 40-------++
Aesthetics 30+++++00
+ 0161327211220
0 302502920
- 012123212100
Net Score 0 4 1 -5 9 2 20

Recommendation Summary

According to our Pugh chart analysis, the two most promising designs are the one-piece post hole digger and the racheting digging heads design. While the one-piece design currently adds the most incremental value (with a rating of 20) through this analysis, we beleive that the racheting digging heads design (Pugh rating 9) addresses more of the demands requested by current users and from our research findings. This design will provide an increase in digging effectiveness, a reduction in weight, as well as simplifying the digging process, which were all key requirements concluded in our usability studies. The reason why the point count was lower than that of the one-piece design is because these improvements came at the expense of cost and manufacturing complexity increases, which are often necessary compromises for any improvements in performance.

The one-piece design was proposed to provide an alternative to our research findings - rather than focus on improving the characteristics of the post hole digger related to the user (weight,efficiency,ergonomics), this design was focused on manufacturers and retailers, the other primary stakeholders involved. This simple design will greatly minimize the manufacturing and assembly process by minimizing the part count and costs, all in retaining the original effectiveness of the standard post hole digger design.

We request that the client review these two proposed recommendations and discuss with the design team on further pursuits with either design, and to address the primary concerns the client has.

Design Schedule/Gantt Chart

A Gantt chart is a scheduling tool that provides a visual representation of tasks to be completed. It shows the order in which the tasks must commpleted based on dependencies between tasks. The Gantt chart is useful to our design team for laying out a plan to complete reports and protoypes on schedule in preparation for the final Design Exposition.

The Gantt chart below shows specific tasks that must be completed and which team members are responsible for each task. Important milestones are denoted by red diamonds. There is less detail provided for tasks due in November and December, because the requirements for future reports and prototypes have not yet been made clear by the client. As more details become available, the chart can be updated with more detailed tasks and assignments. The "Team Meeting" tasks are not meetings with the client, but rather meetings were the design team will discuss planning and progress towards upcoming milestones. Impromptu meetings may be held as well, and these meetings are not represented on the chart since they are unplanned.


Team Members

The entire group worked in unison on several aspects of this report. The usability studies were performed with each of the group members present, and the brainstorming session and market research/state of the art information was collected as a group as well. The presentation was created as a team also. Our group has been regularly meeting on Mondays and Fridays to collect our thoughts, and has also held impromptu meetings on two occasions. The specific roles of each member regarding the details of the report are listed below, as well as a general list of team oriented tasks.

  • Clay Crites
    • Usability studies
    • Team member roles
    • Design problem definition
  • Rich Pantaleo
    • Design concepts and sketches
    • Pugh Chart write-up
    • Design schedule/Gantt chart
  • Nicholas Roche
    • Expert analysis
    • Design concepts and sketches
  • Jeffrey Wang
    • Executive summary
    • Market research and state of the art
    • Recommendation summary
  • All members
    • Responses to report I
    • Performing usability studies
    • Brainstorming
    • Market research and state of the art
    • Narrowing choices for design concepts
    • Pugh chart


Burns, P. "Five Styles of Post Hole Diggers." 7 Oct. 2008 <>.


Team 2 Brainstorming

  1. Fence post that digs its own hole
  2. Train prairie dogs/gophers to dig holes
  3. One-handled design
  4. Rotating digging heads
  5. Pogo stick with digging element
  6. Ratcheting digging head closing mechanism (foot operated)
  7. Ratcheting digging head closing mechanism (hand operated)
  8. Scaled up egg beater design
  9. Automated auger (own support frame, etc.)
  10. Movable foot peg
  11. Adjustable weight (add/remove masses)
  12. Pneumatic impact hammer
  13. Pole-mounted mini auger (electric power)
  14. Pole-mounted mini auger (gas power)
  15. Pole-mounted mini auger (air power [compressor])
  16. Robotic gopher
  17. One-pass digger
  18. Hose-powered earth hydrator (softens dirt in specific area for easy removal)
  19. 'Hoop' style handle grips
  20. Telescoping handles
  21. Teflon-coated digging head
  22. Serrated digging head jaws
  23. Explosive charge deployer
  24. Heated digging head (burns through soil/defrosts frozen soil)
  25. High-grade, higher quality steel digging heads
  26. Aluminum handles
  27. T-handle design
  28. Surface for driving digger with a hammer
  29. Assistive removal of device from hole (spring)
  30. Tamping heads mounted on ends of handle
  31. Change of diameter of handles for easier gripping
  32. Hole depth measurement device
  33. Hole plumnbness measurement device
  34. Soil hardness detector to optimize hole location
  35. Reverse action of digger (pull handles apart to release dirt)
  36. Claw-style digging head
  37. Vibrating digging head to loosen soil as digging
  38. Shock absorbers in handles to prevent injury/discomfort when striking rocks
  39. High-powered water jet
  40. Digger that runs off of power from car
  41. 2 person post hole digger
  42. Miniature pile driver (drive steel rods, mount posts over rod)
  43. Laser sight for guiding digger
  44. Animal detection
  45. Digging head that is closed on entry so that user releases dirt when you pull it up
  46. Ground/insulation to prevent injury if you hit an electric wire
  47. MP3 Player built into handle
  48. Flashlight incorporated into handle
  49. Disassembly for storage and use as two shovels
  50. Air dropped posts with laser guidance
  51. Air dropped posts with heat seeking guidance
  52. Bike powered auger
  53. Scented bone for dogs to find and create post hole when digging for it
  54. Smaller Size core sampler
  55. Straw to 'suck' post hole dirt up
  56. Air compressor/vacuum to clear dirt out of hole
  57. Self lubricating joints
  58. Built in timer to tell you when to take a break
  59. Heart rate monitors on handles to prevent cardiac arrest
  60. CNC post hole digger
  61. GPS guidance unit for finding locations of holes
  62. Multiple digger heads on auger for digging 3 holes at a time
  63. Auger integrated with weed whacker and moveable vanes to create leaf blower
  64. Acid to burn hole in ground
  65. Self contained post hole digger with foundation, digger, and post
  66. Screw in post
  67. Mist machine to coat body so that you don't get hot
  68. Upper body Exoskeleton to assist with digging
  69. Informational DVD/work out tape
  70. Adjustable Diameter to dig different sized holes
  71. Digging head motion perpendicular to handle motion
  72. Heavy fences that don't need to have fence holes dug
  73. Built in two way radio for large scale operations
  74. Titanium digging heads
  75. Carbon-fiber handles
  76. Steel handles for weight
  77. Tamping/breaking bar incorporated into digger handles
  78. Chain/conveyor motorized digging head
  79. Building code that forbids the use of posts
  80. Design that digs square holes as opposed to round ones
  81. Coin-operated rental digging machine
  82. Fan to cool user
  83. Umbrella to shade user from sun
  84. Digger that allows user to sit while operating
  85. Interchangeable digging heads
  86. Kit to adapt lawn mower for digging post holes
  87. Add-on to shovel for specifically digging post holes
  88. Adjustable spacing of digging heads
  89. Quick disconnect between digging heads
  90. Product shipped to retailer in two halves, assembled in store when requested by customer
  91. 'Knuckle Buster' spacer available to purchase and attach to regular digger
  92. Detachable carrying strap
  93. Mechanism to keep handles closed when transporting
  94. Jackhammer-style impulse mechanism
  95. Add Wiimote and create game to accompany digging
  96. Timer to calculate digging rate
  97. Integrated computer to calculate required depth of hole based on user inputs
  98. 3 part design - two halves, one pivot
  99. Miniature post hole digger
  100. Genetically engineered tree that grows into a post
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