Showroom DIY 2DOF made mostly of scrapyard parts and "top quality electronics™"

Hello,
after wayyy more problems than expected I've managed to finish my 2DOF "scrappy".

As most of metal parts and engines come from scrapyard I didn't expect everything to go smooth and oh - was I right... at least partially - in the end most of scrapyard things were totally fine, only "fresh & new top quality MM cheap china!" turned out to be one giant mess

Beginning - the welding and "it was supposed to be straight" phase




Painting phase


"This goes here.. or not here. Maybe here?"


Final assembly


Finished !



At first due to case failure of one motor I had to switch it for different one - so here we go, 2DOF on two different motors as I wasn't able to find pair of working ones And... it works.

So everything was working fine, my arduino + top quality™ motomonster were working flawlessly... for first 3 minutes then entire thing started to dive. Turns out one of the chips was broken. Happens. So I ordered another one, this time from "more expensive best quality shop™". And you guess it right. This one also came borked.
And here i am - with 2 motomonsters, both with one working and one broken chip and scrappy being very stable 2DoF notmotion platform.
So... instead of ordering yet another top quality™ motomonster I decided to try to use those 2 partially working MM at once.

Spaghetti


And... again it works ! Although it looks like spaghetti. To make it work just connect both mm the same way they are supposed to be connected to arduino. Just may have to swap motor cables if your working chips are both 1s or 2s.

So only thing missing is pot mounting. Hmm. This just begs to be 3d printed.
<2 months later after parts for 3d printer arrived and I've built it and learned to use it properly>

Finally, time to attach those pots!


Seems to work properly, pot still alive


Yay! Time to connect wheel and drive! Hmm where is this smell coming from.
Abort D: !

<sometime later after isolating 2nd engine and G27>

Finally, the moment has come!


Scrappy is alive.

If anyone is interested in 3d printed files I included them in attachements.

Good job, keep hitting the scrap yards. You will find a suitable motor.

I may give it a shot one day, but so far current setup works fine - seems both engines have similiar specs

Indeed - it was reversed, must have forgotten to check settings after engaging "dual MM same chip working" spaghetti cable management . Thanks for pointing it out.

Tip for ya, Go through EACH individual force One by one, its the ONLY way to ensure your axis are correct.

™ lol.

Look, I run MMs on my 6DOF, which have worked fine so far, but the pain I went through to get 12 reliable sets, add cooling and regenerative measures . This needs to be a sticky - If you want to keep your hair and sanity - don't use Chinese made MMs (even the slightly dearer ones come from China) use a set of Sabertooth 2x32 or 2 x 60 !!!!! If I was building my rig again that is what I would do. The Sabertooths may be more expensive initially, but come with their own cooling system and are designed to handle the regenerative issue of driving big DC motors. So in the long run will likely be a much better investment and will not trip out from overheating or regenerative problems. Just do it! Also while I'm at it - LED power supplies for the win for big DC motors.

I have been checking for freebies myself. Got 2 24 volt wheelchair motors and some of those fancy rod ends today. Have some exercise equipment for frames. Id like to see how you have started

Our scrapyards aren't free, just pretty cheap
Unfortunately I haven't been doing photos at 'collecting' phase. Earliest photos I've made are the ones in the beginning of opening post.

I'm considering using LED lighting power supplies for my build as well.
Currently using a couple for other projects (3D printer & audio amps for SimVibe) and they are holding up well.
Thinking about using a pair of 12v 30A (or 40A), one for each PGsaw 25:1 and their relative JRK's/components.

How are yours holding up vs the typical PC/Server PS's a lot of folks tend to use?

if they can give you the amperage, you are just fine! (i used small psu, and after a long time of having troubles) (the jrk disconected again and again) i found that it was the psu (but it was an small one, not a server psu)