First attempt - 6DOF and learn to TIG weld at the same time.

Thanks, @Zed! I'm not worried about heat as I'll be welding small tabs to the frame about midway between each set of motors. And definitely no electronics connected at this point. I was trying to wrap my head around whether or not the motors would be part of the circuit. If I attach my "ground clamp" to the tab I'm welding, I should be good to go, yes?

I would think so. As long as the motor leads aren’t touching anything I would think you would be fine.

Phase one complete. It's pretty ugly. I think I'll make it a rule that all riders put on the Oculus before approaching the rig.

Now on to the electronics. Reading through @SilentChill's experience with motor drivers, I'm thinking that Sabertooths are probably worth the investment. Any advice on 2X32 vs 2X60? I am using 12V crab pot puller motors. If I read correctly, I can control 2 motors with each Sabertooth, correct? And is there a consensus (or at least a plurality) on whether it's better to use capacitors or a car battery (I think @SilentChill used just one)?

Anyway, thanks for all the help and advice so far. Here are some photos:

It's beautiful! And you can always fix most things aesthetically with some flat black to make it all disappear . Exciting to see this stage of build, looking forward to seeing it wired up and moving.

@Limongi, "A grinder and paint make me the welder I ain't!"

Yes. With all the issues with the MonsterMotos copies, Sabertooth is the safe bet. If you buy the original ones, then the price is almost the same.

Depends on the current. Do you need 60A or 32A is OK? Yes, each Sabertooth can control 2 independent motors.

If 2x32 = resistors (provided with the sabertooth)
If 2x60 = battery

I'm not really sure how to estimate that. I'm using those crab pot puller motors that a lot of other people here seem to have used - 12V, 50:1 gearboxes. I have the same LED power supplies that @SilentChill ended up using. The electronics are more daunting to me than buying a welder and teaching myself to use it was. The Sabertooth drivers aren't a small investment, so I'd like to get only what I need, but I also don't want to underestimate.

@Squonk - I'm using those 50:1 worm gear motors from pgsaw on eBay and have fairly fast response bar graph ammeters on each axis. Full scale is 50 amps and that's the rating on my power supplies that drive them. There's a video in the first post in the thread. (https://www.xsimulator.net/communit...o-do-motor-current-sensing-for-balance.10510/)

Anyway, I have a little bit of filtering in the circuit so the peaks will get shaved just a bit, but you can see in the video that on my rig (full frame) with my weight (~220 lbs), the peaks are sometimes going a hair over half scale - ~25 amps. Mostly the current is in the 10-15 amp range. I would bet that the true currents are 30-35 amps peak and possibly a little higher due to the peak shaving property of filtering.

The speculation part: Thing is that for most power handling, they quote average powers so the 32 Amp Sabertooths might be OK but I'd be tempted to go with the 60 amp versions just to be safe. A 2 dof is very different from a 6 dof for motor loads. My weight is balanced over the pivot while yours will need to be dead lifted. You'll be holding at stall a lot more even with the worm gears and air struts. I can back drive my motors fairly easily when unpowered and that's on a 2 dof so I'd bet your motors will be pulling a fair amount of power on average to hold position and especially to accelerate against gravity. You may even need to cool the motors themselves. I haven't used the Sabertooths so don't know how overengineered they are. Could be the 32 amp versions would be fine but I would bet you would be on the edge.

Hopefully others can comment. I don't have direct experience to go by on 6 dof power requirements. Also, going with 60 amp Sabertooths doesn't mean you need to have bigger power supplies as long as they can deliver what you are actually using. Those pgsaw motors will also have a maximum stall current that is set by the winding resistance. If it is below the 32 amp rating on the smaller Sabertooth, as long as your motors can exert sufficient force at that stall current, you don't need bigger Sabertooths. I looked to see if anyone listed a stall current on them but couldn't find it. I didn't look especially hard though.

If you can measure stall current on a motor, that would tell you a lot.

Thanks, @Zed. That's really useful advice. I will probably go with the 2X60s, hoping I can use just 3 to drive the 6 motors.

This should also tell you how to take a rough guess, if you want to double check for yourself
https://www.xsimulator.net/communit...motors-stall-current-safely.9188/#post-116112

Thanks, @Tim McGuire. I'll give that a shot.

Quick question to builders who received a free DIY license: How long did it take for your application to be approved? I haven't heard anything on mine, and while I don't want to assume that my project will meet the requirements, I am kind of champing at the bit.

Thanks, @noorbeast. The Sabertooths arrived today, and the power supplies and assorted relays, kill switches, etc. are on hand. Hoping to wire it up this weekend.

Will do! And, with luck, none of the photos will show any magic smoke being released.

One power supply DOA, so a little bit of disappointment and a slight delay while waiting for a replacement, but the rough wiring is done, and I am in possession of a DIY key! Soon...

Is anyone else using Thanos' AMC1280USB controller?


I've reached this point in my wiring, and while I've read through Thanos' blogspot and watched some of his YouTube videos, I can't seem to find a user manual. So if anyone else has experience with this, I have some questions...

EDIT: Never mind. I found a dropbox link where Thanos has posted some diagrams. Here goes nothin'. Hold my beer...

Rigged for maximum smoke. Holiday festivities and obligations will delay testing for a bit, though. Happy holidays to all, and thanks for the help and support you've provided!

Well, 9:00 on Christmas Eve is probably not the ideal time for a first test. Good news is that the motors all seem to be working, and were unable to break the platform or bend any rods while spinning though 360 degrees. Also, no magic smoke was released. Bad news is that I did not have any control of them through the SimTools Output Testing interface. I used the settings provided by Thanos in this link: https://www.xsimulator.net/community/threads/thanos-amc1280-help.6045/

The interface did find a com port (6). I imagine there is more than one important thing that I'm missing, but, as I said, this probably isn't a great time for testing. I'll appreciate any suggestions, but in the meantime I'll breathe a sigh of relief that nothing broke or burned up the first time power was applied.