As well thought out as this is, this strikes me as extremely (over) ambitious. You are not asking for a lot of money and I'm sure you'll learn a, lot but I fear you will end up contributing little. It would be nice if you could break this into a bunch of sub-projects, in such a way that even if you only succeed with the first one, there will be something usable and testable for other people to work with. Can you structure your project that way? If so, I suggest you propose the first sub-project or two with enough detail convince us all that it's doable and worthwhile, and layout the later sub-projects with just enough detail to convince us that there is a road forward....

Mr. Schull thank you for your comments,

After reading this, I understand that given a multifaceted project as this one it is understandable that by breaking down the project into different stages this would allow everyone to see how design is progressing and whether the project is on track to be successful. I was thinking about this for a while as to how I should divide the project where the lines I drew between one stage and the next made sense in a way that would make as much progress as possible.

I think the best way to do this would be to divide the entire project into two parts which are 1) mechanical assembly, and 2) the integration of electronic components. To define these two stages first, mechanical assembly will encompass the assembly of all 3D printed parts using the hardware detailed in the cost spreadsheet (bolts, nuts, bearings, standoffs, etc.). On the other hand, the integration of electronic components will encompass components such as servos, the micro-controller, battery, voltage regulator, current sensors, etc. and their integration into the rest of the assembly.

Talking a little bit about why I chose to divide it this way, for the mechanical assembly, I realize that just including my pictures of CAD with descriptions here would not explain design as well as if given an animation or video of an actual model. This is the purpose of this step. By assembling the 3D printed components and hardware to give an actual model that can show exactly how the arm will work, this will give you all a better idea about this design and be helpful in getting funding for the second stage.

For the integration of electronic components, I chose to make this one stage rather than divide into many parts because I did not think it would make sense to test and prove electronic components that don't really have much room for error, before having to reapply for funding to purchase the next set of components. I say this as unique to the components I am asking for because I am not using any components that are very complex or difficult to use. With parts like servos or the Myoware EMG sensor for example, these are relatively straightforward to use for my purposes. I don't think it would be wise to separately request funding for things like this to test and show results of the EMG sensor translating into servo movement before again having to apply for funding for the next set of electronic components. I also see having this be one stage beneficial in that it is the quickest way to find any flaws if I am able to have the entire system working together. This would give me valuable information, especially regarding how much current draw I can expect cohesively, which would then allow me to confirm whether the battery I have planned is/isn't sufficient.

I would really like to hear your or anyone else's input on this organization before I submit a proposal structured this way, so please let me know what you think. Thank you.

Thanks for your responsiveness (and thanks to everyone for the constructive input).

I think Mechanics and Electronic are good sub-sub-projects. I'd suggest that you define subprojects around sub-components (e.g., Thumb or Finger or Wrist) as well (which could then be broken into Mechanics and Electronics).

For example, a working Thumb (Mechanical and Electronic) would be a good stand-alone contribution and therefore good first sub-project. If you delivered nothing else, you'd still have delivered something that people could use and build on. A whole system like a hand (mechanical or electronic) is a big project and if anything fails, everything fails. That's what you're trying to ensure against.

I suggest you look at +Eric Bubar's current sabbatical project. Much less ambitious, much more modular, probably wider application, and probably more likely to succeed. Simple is hard!

A Thumb-up for an e-thumb

BR/Yoav

Thank you for the clarification Mr. Schull,

I think I misunderstood what you meant the first time then, but I understand what you mean now. I am however somewhat confused about how I should go about approaching this project using standalone sub-projects built around sub-components.

With the thumb I have designed for example, my confusion comes from how in the context of the rest of the hand, the thumb is not really meant to be a standalone sub-component as it relies on a servo that is not mounted inside the thumb piece itself, but inside the hand compartment (see attached picture below). The reason I say this is because as a result if the thumb alone was assembled, being not entirely modular it would be just as valuable as if the rest of the arm was assembled simultaneously which would be more efficient, because both yield the same resulting thumb. Not being entirely modular here, however, I don't think this is much of a barrier in the way of improving on a component like this because although the servo is housed inside the palm area, the 3D printed thumb assembly can still be completely detached with all phalanges still intact, via 2 bolts. But again, with this design being relatively simple (cable "tendon" passing through thumb base to pull on upper phalanx) and a proven concept used by so many other tendon driven designs, I don't think it would be efficient to assemble this component alone before reapplying for funding to move on to the rest of the design.

Similarly, the design of most if not all of my arm's sub-components are like this where they aren't necessarily able to be stand-alone components, but can be easily modified and improved on because the only part generally separated from the component is the actuator, which also can be changed should whoever is improving on this design desires. This is because the method power transmission (flex drive shaft and cable) is independent of the type of actuator used.

Addressing the other two sub-component examples then which are the fingers and wrist, these components also follow this pattern as each of the four fingers can similarly be detached used two bolts to separate the 3D printed finger assemblies, but cannot function standing alone because the servo actuator is mounted in the forearm. Again here, I believe it would be more efficient to assemble the rest of the arm simultaneously as there would be quicker progress and the finger components would be just as valuable as if isolated. The wrist also follows this pattern but for a different reason as it was not so much designed to be a component in itself, but more an adaptation to the forearm's geometry to allow for wrist rotational movement. Specifically, the wrist component here really is only a servo attached directly to two 3D printed parts that sit on two bearings. Here, rather than a wrist which usually sits right under the hand that allows for the hand's rotation, the entire hand + forearm section rotates as one unit with the outer braces/socket remaining stationary to allow this rotational motion. This is to accommodate the flexible drive shaft passing through the "wrist" region which does not have torsional capabilities.

That said, I think that the best way to organize this project would still be by dividing the mechanical assembly stage, and the electronic integration stage. In addition to the reasons in the previous reply, such as giving a better illustration of how exactly the design works, the low-complexity of the electronic components I am dealing with, and the data that can be obtained from a cohesive electronic/mechanical system, I think this is the best way to improve rate of progress while giving enough focus to the development of each component. In this way, even if any component fails (as in the result of a design flaw), this could be fixed in the mechanical stage with the parts being redesigned and reprinted without allowing the whole system to fail. Even with the electronic components, failures here with a servo breaking for example would most likely be a problem with the servo itself as the power transmission methods used here are very simple.

I think the important question then when considering this should be specifically how a failure might occur, rather than if, and how this has an impact on the rest of the system because given a somewhat modular design, one failure may not necessarily lead to total failure.

Bhargav I am glad to see that this is well thought out and you seem like an able student.

Thinking in terms of funding: I would vote yes but here are my comments:
1) I agree with Jon that setting mini-goals within this project will be helpful.
2) I think it is important for you to share your progress, files, and what you've learned throughout the process so other can continue it rather than starting from scratch (this is a big, complicated challenge to our open-source movement).
3) make sure you've taken the time to see what options are out there on thingiverse and other sites, read the comments and (if possible) spoken to users. Size, aesthetics and weight are all factors that can doom a device.

4) for the bigger picture, it could be helpful for voters to know what the overall budget of the fund is. That would help address the concern that will almost definitely be brought up: "I don't think this should be funded because it sets a precedent for every other EM design to be funded" - which is a valid concern for sustainability of the fund. However, that doesn't mean the community should avoid funding anything like this, IMO. There's a balance between the all-or-nothing mindset.

I'm only able to mostly skim over what was written so I apologize if I missed something important.

Thank you for your comments Mr. Powell,

I agree with the use of mini-goals in this project as they will definitely be helpful for me and whoever is following the project. About the open source idea, I also agree with this as you might have read in my draft proposal. I actually think I will start documenting all of my steps as soon as I start assembly rather than later, so that any difficulties or important details will be recorded, again for the reasons you outlined. Also, when you say budget for the fund, do you mean like a cost breakdown of the funding I am requesting or is that wrong? I assume this is what you mean because doing so would allow maybe not the total amount being requested to be immediately fulfilled, but could be funded in part based on how the funds are distributed (according to a cost breakdown), which should avoid the all-or-nothing mindset I think. If this is what you meant, you might have missed it but I included a cost breakdown spreadsheet with explanations in my draft proposal under "Amount of funding being requested":

"Please refer to the following spreadsheet for all details regarding costs and funding:
https://docs.google.com/spreadsheets/d/1ue6cWVnkKPzd1UW-p4PodXCmFX0dN42_Daxiv5_ecCE/edit?usp=sharing
Please be sure to click on the highlighted cells to read the notes I have included for important explanations."

**Also quick update, I forgot to include the price of the DC motor driver in the spreadsheet at the time of the original post but that is now included which increased costs by $3.49. The actual DC motor is not included here because I still haven't quite narrowed down the exact link I am buying from, but the cost is very small anyways (looking to be about a dollar or maybe less), or I might be able to salvage one.

Hey guys, I also had some questions about how the research approval process worked. Looking at an older thread about this process, I found this document: https://docs.google.com/presentation/d/1SClcxQl4IE6ycb2FXvYz6oalHsayDLRR_l1W90Jq-8c/edit#slide=id.p

Because this proposal will be requesting funding, according to the google slides document it will be reviewed by two reviewers from the e-NABLE research subcommittee. If this proposal does not get passed, would the reviewers give me feedback on the reasons why they denied the proposal and would I then be allowed to make any changes to resubmit the proposal? Also assuming the proposal does get passed, where does the money for the funding come from and how exactly does the researcher receive this? Thank you.