Bruce's 2dof fullframe rig aka: the "Ratrod"

ok so im about 175lbs and with the static rig it adds up to close to 300lbs or 136kg total. I can trim a little weight on the static rig but ill also have to add because it will twist. It also lacks any support or framing to hook the rods to. the r/c pot gear reduction may also be to much as it is a little over 2:1(17t and 37t gears). It looks as though ill need better pots or a smaller reduction. I used some traxxas off the shelf gears and drilled them out. the motos and collars for 5/8"keyway should be here by 7-14. the way it stands i only have about 3/4" clearance between gear and body of motor for arms. I am still not sure what im using for rods or connectors. Still looking for easy and cheap. I will shop tomorrow. maybe get lucky and find a solution for the keyway collar/arm and can cancel the 17usd each I ordered.

ps. Before i came here I had no clue about any of this. I would never have attempted such a bold project by myself. Your hard work has given myself and many others the confidence, tools and collective wisdom to create. ty all. hope I can repay your efforts.

ok update. my motos came early. got them yesterday so i started making my control box and getting the wiring square. I re-purposed an old psu from a pc. lol what a mess.

@noorbeast so I get everything wired all fancy and .........nothing
Maybe a victim of the doa mms @SeatTime mentioned.
I' m using 2 and have two for back up.

One of the biggest faults is we solder and build all together without testing the parts before. Second the MMs are very "sensitive" if the temp of your solder has been to high, the board can be damaged. Third further I determined an issue shown by the picture attached to the posting. The screw covers the LED pins and if they will be damaged the 12V is going do destroy the MM.

Ok I will check the screw. Thank you for pointing it out, I never would have noticed. Lol. I never thought this would be too easy. Just a little learning going on. And we all know an education isn't free. I have back ups. Heat from solder shouldn't be a problem. It is one of the few things here I have a little experience with as an HVAC tech years ago.

You are welcome. HVAC stands for Heating, Ventilation and Air Conditioning?

Seems to be a hell of a lot of crappy MM's flying around

Yes, heating and cooling sry. Ive had a few different jobs over the years, mostly in the building trades. I was also a firefighter for a few years.

Great to hear that. If you will burn the MMs you know what to do

yeeeeeees! ok got 1 motor working in smc3 utils. so it was a bad solder joint(cold joint at 12v pos out B2 on mm). Both @noorbeast and @Pit mentioned it and I should've checked better. when i wiggled all of the wires it came off resoldered and got left side chasing blue line. so stoked gonna mess with the other one later after dinner. Im sure its something simple. If not got two backup mm's.

ok there is a difference and im not sure why. motor 2 also will set just short of target and i can move slightly by hand before power gains to resist me. i can hear psu ramp up if i lean on the arm. also Axis 2 will not work in simtools. no matter the setting but motor 1 works fine? why is there so much difference in the yellow line(pwm). motor 1 seems way more responsive.

so i can stall the motor if i put 30 to 40 lbs on the arm. signal clipped no movement i can set the arm manually by hand and it returns to normal. motor 1 does not move at all under same condition it resists me with more force than i can apply by hand.

i can move it by hand and it will resist, or i can set it here just a little off the target and it doesn't move but is trying to again only at reverse.

gonna switch up psu's and see. hope that it is not a motor/brush issue. I don't know lol I'm so new at this. but it is fun so far.

it does this too. still seems like a lot of pwm at the point it calls for rev.

You said the whole platform is 136kg total. The motors draw 24A ergo IMO the MM are "overworked". Probably you have to use a dual half bridge, meaning two MMs as one bridge. You are using the MMs as a half bridge already?

@Pit there is no load at this time...sry I should have mentioned that i am testing without the rig attached to the base. its just arm that weighs about 5oz each. motors may be too big (ie add more mm's) we will see, but you would know best. it works ok in simtools/iracing. waiting on thermal tape for mm heatsinks tho so i can't push it to tell. I've got two spare mm's so i can go that way if needed.

Have you tested each output on the MM's ?? A1+A2, A1+B2 AND B1+A2 B1+B2 with a motor in both directions, sounds like your having same issues as me with dodgy MM's

Hope it works out @SilentChill. My mm's tested ok. Haven't opened the other 2. Are yours marked "spark fun" on the back? They do get hot quick. No heat sinks yet. Didn't have fans wired in then but was just testing. I didn't push them for long. Only a few minutes. Never hit thermal shutdown but Imo I had to be close. They were very hot.