Good luck. I look forward to seeing something working.
@hallowed31 thanks man! Yeah so do I. It's like crawling after a carrot on a string and each time I bend down to take a bite, somebody yanks the string and the carrot moves 5 feet away and I have to crawl after it again. Getting the robot moving is the bite. It has been yanked away from me 100 times. Now each time I bend down to take the bite I doubt I'll be biting it and am ready to begin crawling again in the back of my head. It's tough.
Ok..All the best for this endeavour.
Here is a updated drawing design for the 64:1 downgearing pulley system for the index finger actuation of the distal 2 joints of the finger. On the bottom right is a zoomed in view on the lower set of pulleys and their routing. The bottom most 3 pulleys in the zoomed in portion I have now built and photos of them are as follows below:
As I'm now 90% through making my first 64:1 downgearing Archimedes pulley system and testing and debugging it, I now have more precise measurements for the Archimedes pulley system's total size. I updated the size of it in my main CAD model for the robot and it was a good 18% increase compared to my initial estimates. I realized I need to figure out how to fit all my pulley systems for the hands properly for every muscle of the hands/wrist in my main CAD model - especially since the pulley systems are taking more space than planned. Turns out, I needed a bit over 40 pulley downgearing systems for the hands and wrists zone and due to their larger size, I could not fit these into the forearms along with the motors I had planned to place in the forearms. So instead of moving the pulley systems into the upper arm or torso, I realized the pulleys would be best placed in line with the motors and what the motors are actuating (the hands/wrist). So it was the motors in the forearms that had to go elsewhere. I placed all of them into the torso, mostly the lats area and some in upper back tenderloin area too. So some finger motors are in upper back and their cable routing has to go through the whole arm, be downgeared in the forearm, then makes its way to the fingers. That's a long trip but unavoidable IMO with my design constraints.
I don't think this long travel distance is a big issue since the pre-downgeared cable running from the motors into the arm is high speed low torque so won't have much friction while making turns in the TPE teflon tubing as it isn't pulling hard yet. So these turns as it travels through the shoulder and elbow tubing won't be too bad friction-wise. There's also some nice upsides to moving the motors from the forearms into the torso. One upside is the wire routing for powering the motors is now a shorter distance from the batteries in the mid section. That cuts down on wire resistance wasted as heat. This wire having high amp flow is ideally kept short as possible due to the resistance of the wire and heat that causes. Another upside is the thrown weight is decreased by a lot when the motors are not in the forearms which enables the hand/lower arm to move more effortlessly and move faster as a result. This also reduces moment of inertia (definition: the moment of inertia is a measure of how resistant an object is to changes in its rotational motion). This means it will be able to change directions faster - this will improve its reflexes for example. Now it is a bit scary for me to be moving more components into the torso taking away room for things I may want to add to the torso in the future, leading us ever closer to the dreaded running out of room for things. However, we still have room for future changes and we solved the need for space for gearing for the hands perfectly. And with the above mentioned upsides, this was a great change.
Here's the updated CAD for the forearms: Note: the teal boxes represent a Archimedes pulley system where 64:1 downgearing is to take place.
Update: in testing, I found the string is wedging between the bearing and the plastic discs sandwiching in the bearing. So I need to now make the bearing have a grooved outer race that will keep the string centered on it and not wanting to drift into the crack on either side of the bearing. To make this groove, I plan to super glue two plastic washers onto the circumference of the bearing and have the string stay within these two plastic washers that form the groove. Commercial pulleys always have this kind of groove and now I've learned the hard way why it is necessary. So I am looking to replace all the pulleys I made so far unfortunately as they are not dependable.
Its the journey not the destination.
Took a little break on the pulleys work to rig up the cables into the index finger to test the grasping of the index finger. I ended up using 70lb test PE braided fishing line for this and 1mm ID x 2mm OD PTFE teflon tubing as the guide tube. I sewed the fishing line into the index bone fabric around 1/2 cm distally from the ball jointed hinge. In testing, it appears the total draw distance to fully bend the index finger is 0.75". My pulley system is set up to draw 24 inches. 24/32 is .75" so 32:1 downgearing seems fated to us after all (down from our previously intended 64:1 downgearing). Otherwise I would have to greatly overhaul the pulley system design again and I just don't feel like it anymore. So my copium then is 32:1 will make actuation faster. We lose strength but gain speed. 32:1 also saves us making a second plain bearing per downgearing system which cuts down on parts and labor. It also is that much less friction in the pulleys since plain bearings will be more friction than ball bearings.
Note: the friction in the pulleys, although not ideal, do have a hidden upside: once the joint is in position, it can hold that position without as much motor straining since the friction makes the pulley system want to stay in place so the pulley friction can pretty much hold a joint in a given spot without much help from the motor struggling to maintain the joint angle.
Also of note: I found the best way to sew down the teflon guide tubing is to wrap it in fabric tape consisting of compression shirt fabric and 3M 300LSE adhesive transfer tape. This very sticky tape wrapped snugly onto the teflon tubing I can then use as an attachment point for suturing the tubing into the bone fabric tape coating. I got it all very snug this way. The suturing I'm doing with a curved suturing needle and surgical pliers and nylon extra strong upholstery thread.
Also of note: I tied the string for the distal joint and the second to distal joint to one another and will tie the string coming off the pulley downgear system to these. I am actuating both the distal and second to distal joint with a single actuator since these two joints generally move at the same time and about the same amount on a human finger. No need to use one actuator for each joint since they always move in sync.
Note: I was surprised it took 0.75" of draw to fully actuate. I thought 0.375" would be plenty (which is what the 64:1 downgear would give me - 24"/64 = 0.375") but I was wrong. Oops. Another mistake. Proves how testing is so important. But assumptions are necessary stop gaps to move forward and can get you in the ballpark and testing adds the correction to any assumptions that were off. This is all so experimental and full of uncertainties but we press on.
Note: once we fully establish and test a thing and have no uncertainties about it anymore, confidence shoots up even higher and we gain momentum and move into just repeating the processes we established before that led to our successes and it becomes a bit more rote and mindless and relaxing work. But when everything is uncertain and requires such intense thought and concentration, things are very taxing. It is much harder to stay motivated when doing anything requires so much brainpower and planning and care. I very much look forward to dialing in my methods and not having to think so much to make any meaningful progress since I'll just be repeating things for the next joints, doing the same as this one and can shut my brain off while doing so a bit more. The first run through is by far the hardest. Which reminds me of a product I invented and the making of its first prototype took me 20 hours but after making hundreds of this product over the years, now it only takes me 3 hours to make. Things get so much faster once you know what you are doing and have jigs set up and a streamlined process. Everything is excruciatingly slow when you don't have a streamlined process or jigs set up or special custom tools made. So this is the hardest phase right now and I just have to stick it out and then I'll be home free.
I recently had an associate disagree with me that if I push through this phase of the project I'll be home free. He said he thinks the AI relating to robot balance and sensory input and physical execution based on sensory feedback will be the hardest part. While I agree that will be time consuming, I don't think it will be nearly as "hard".
My instinct is that those purely software challenges are not as "hard" for several reasons. First of all, consider that in 2009 a Japanese institute of technology - mere students, solved all of those challenges with HRP-4C which would walk and dance and everything and this was just student coders doing this in their spare time while maintaining their entire class load as well. In my view, the hardest part of the project is maintaining personal belief that I will succeed and not giving up like 99% of others have who set out on this bipedal android dream. There is a massive up front money and time investment and EVERYONE tells you this cannot be done and you are delusional. Pushing past the initial design challenges and hardware development to get a functioning prototype is then the hardest part by far. Once you have a working design that overcomes cooling issues, noise issues (runs silently), space issues (can fit all the crap that has to fit) and all the parts and assembly is of high quality and successful, and you had to learn and half master about a dozen fields to get here mind you, ONLY THEN are we talking about advanced AI implementation to synchronize it all and bring it all to life properly in the ways you mentioned. Well consider this: by the time you are in that phase, you already have proven to the world you are not delusional, have a amazing piece of technology - bird in hand, and now have immense confidence and momentum going into the AI phase where balance and walking and whatnot challenges are faced off with. This is SO MUCH EASIER since excitement and morale are at all time highs, you no longer have overwhelming apathy or nay-saying from all sides on your dream, and you have built a massive fan-base rooting for you. So even if the complexity or time investment may be higher on the challenges you mentioned, the morale boost and momentum make that phase easier since it is not the implementation challenges that are hardest but the motivation and persistence and perseverance against all odds and emotionally bearing all the nay-saying and hating that is hardest. Also the fear of the unknown and fear that you will just never make it or will die long before the project could take off fears etc. Overcoming all of that is the real challenge of something like this. Maintaining faith in the vision despite most everyone having faith against the vision is not easy and even your own mind whispering doubts at times that you have to shoe away. You are just mentioning complexity and technical execution which to me is not all that hard. Also note: the other major battle in the hardware phase I'm in now is that a great deal of the approaches I'm taking are entirely novel and untested. Almost everything I'm doing has no guide, no other successes to base off and glean confidence from, and at every turn what I'm doing could fail majorly and have done so. This means you always wonder will I just hit a dead end and have to start over which has happened to me over and over which is very demoralizing especially when paired with naysayers and haters overwhelmingly apathetic and negging my whole dream. Its a lethal combo. Whereas the AI tech you described harmonizing all the sensory input and perfectly bringing the hardware to life in the real world is stuff that has already been achieved and would not be novel and would not be unproven and would have no risk of dead end or wondering if it is even possible since trend setters have already proven this works and there is already a great host of information on all aspects of that and you don't really have to blaze your own trail in those aspects. There is most likely even documented successful strategies for nearly every single aspect of it - unlike the novel hardware and mechanical engineering phase I'm in. So that part doesn't take as much blind faith and assumptions but rather is a surefire guaranteed part where failure is not possible given enough time and patience and perseverance which will be easy to muster with the whole world cheering by that point (whole world meaning just whoever stumbles across the project by that point of progression and leaves a positive note etc).
So to sum, when you have to maintain faith that you will succeed at a dream that most say is impossible, improbable and is surely doomed to fail and they utter this with total confidence in mass numbers with near total unanimous accord, that is hard. That is the hardest part IMO. Maintaining faith against such opposition in viewpoint from so many puts one into the realm of delusion in the eyes of most. How is that not delusional to believe a thing to be true - that you are capable of "the impossible" when most everyone else can plainly tell you are not capable of it and are too blind to see it. That is the definition of delusional. It is narcissistic grandiose delusionality disorder and it is also Dunning-Kruger effect in full force. You have to walk in those titles and persevere as a madman. But the funny thing is, IF you do push through that half wondering if you are crazy for long enough and you manage to succeed, suddenly, you aren't delusional, did not have Dunning-Kruger effect, and were totally sane the whole time and just everyone else was wrong all along and you were right the whole time. The entire cards all flip and you are the vindicated one and everybody else has to hang their head down and admit they were wrong and apologize for hating. It is a remarkable thing how the tables can turn.
One day later:
As I edit the above writing, I am realizing I missed another MASSIVE hard part of the project I never mentioned. Perhaps even on the same level of hard of the things I already mentioned. That is the managerial execution on your life to make such a big and time consuming and money sucking project possible over a long haul. You have to convince your family to "put up with" the project and compromise with them on also maintaining acceptable progress on other initiatives they value higher than your android project. You have to manage your finances expertly in order to be financially stable enough to put thousands of dollars into the android project over the years. You have to manage your time in such a way that you are able to carve out enough time to make meaningful and consistent progress on your android project over the years despite so many other pressing time draws constantly barraging you over the years. You have to manage your emotional and spiritual condition so that you are able to maintain high morale to even be productive over the bear minimum of just doing your absolute necessities day by day. You have to manage your energy levels and health so that you have enough pep in your step to be able to not only take care of your family and friends but also your job and household responsibilities and on top of ALL OF THIS manage to STILL have the energy to pour COUNTLESS hours into your android sustainably over the decades. You also have to maintain your vision and not let scope creep or distractions or self doubt erode at or take away your vision entirely. So in other words, to sum, one of the hardest parts of such a massive project has NOTHING to do with the project itself AT ALL but has everything to do with managing everything else in life outside of the project with such excellence that you are able to execute the project and carve out the necessary time and resources for the project while also expertly managing your own life in all other areas. If you don't do this, similar to the idea of technical debt in a project, you end up with life debt on account of your project which forces your project to fail. So for example, lets say you racked up $20k in credit card debt while neglecting to work or pay your bills and buying parts for your android and working on it exclusively to the detriment of your financial situation and money earning capacity. Yes, that made you able to make vast and fast progress on your android project, but at what expense? Financial ruin? That is not a sustainable approach. You cannot just ignore these other key aspects of life and go all in tunnel visioned on such a big project. That might work for short term projects but long term projects you can't just press the pause button on the rest of your life and expect it not to come crashing down eventually as you neglect everything but your android project. This will come back to bite you. So you MUST establish yourself with great stability in all areas of life FIRST before you can sustainably perform the android project without it harming other areas of life. Or consider relationship with family and a significant other. If you go all in on a massive long term project like the android project, but in the process you neglect family and friends or your significant other, you end up causing them to think you don't care about them and may lose people or ruin these relationships in your pursuit of your long term project goals. That is not sustainable or responsible and is reckless and selfish to go that route. Or how about your weight? Are you going to spend so much time on your long term project and maintaining your income and relationships but throw your health out the window in the process and not make time for the gym or healthy eating? That is not sustainable either. So you MUST take time to be a great caretaker of your health. So then to sum, you must master life in all areas and be stable across the board in order to execute a long term project without neglecting and ruining all manner of things in the peripherals. So for that reason, I say the success in all these peripherals is one of the hardest parts of such a project and if you can master this, the project is a piece of cake by comparison.
And that's why I stick to relatively small, manageable projects that take me about 3 months in length.
that's nice but will never be nearly as epic, exciting, or inspiring and will cause most to just yawn when done. Not fun at all imo to get a yawn as the response.
correct. non-ambitious, unimpressive mini projects are not worth doing IMO. I aim for very impressive projects that are very ambitious and inspire others and maximize my own personal challenge and sense of accomplishment and skip all the baby stuff.
I have a problem where I tend to loose focus on a project if it goes on too long. Finishing what I start is important to me. I have a buddy who takes on big projects but never finishes any of them. He's got about 4 planes, a couple of hovercrafts and some trucks all in progress.
And I do projects that interest me, not to impress other people.
That's fine to loose focus on a big project. Healthy in fact. You have other important stuff to do as well after all. But you keep coming back to it when you have the time and energy and interest again. So for giant projects, having many of them open is a good and healthy juggle. That doesn't mean you will never finish either. Eventually you can finish them all or at least some of them. It isn't only about finishing either its about enjoying the ride.
Projects that don't impress other people will not interest you as much as projects that not only interest you but also interest most other people and impress them and you. That's robbing yourself of something a lot more satisfying and is also most likely settling for mediocrity as well.
Also, when someone opens six decade long projects, and its 5 years in, and none of those six projects are done, does that mean he never finishes projects? No. It means the minimum of 10 years hasn't elapsed so its impossible for one of those 6 projects to be done and having 6 extends them all to a even longer timeframe since you divide your focus by 6. None of this means you will never finish them though. Eventually they can all get done unless you die soon of course.
It sounds like he's having fun, which might be the actual goal 
I will say this though: ideally, I would like to finish ALL of my big projects I opened in the past and eventually I am cutting off any further big projects for the most part until I finish all open big projects. Leaving lots of unfinished big projects when you die is not ideal IMO. So timing it all and accepting you are at a big project cap with no more time to do much more than the older ones is a factor I want to keep in mind as I approach my death.
His only problem is he needs more land and a bigger workshop. 
not sure on that. The constraints foster creativity and may prevent him from becoming a hoarder TBH. Otherwise with more land he might end up with 500 boats and cars and stuff he plans to "get around to". I won't deny people can go overboard on too many big projects lined up.
You might heed your own suggestion. When will this thread showcase anything at all to do with Arduino?
Hallowe'en enthusiasts respectfully disagree 