Showroom My 3 DOF seat mover + GS-4 + Simvibe

Hey SeatTime, Good call on the gear box itself maybe being the culprit, Yes Richard, Try the motor's by themselves if they Check out fine, then we know its the boxes, If they Dont and cause the same issues, We know its sheer motor related.

Yeah. That is what the manual said but it is erroneous. We tested this with our scope when we first had this problem.

I think what is happening is that the current draw is going so high that the JRK is detecting it as a short.

@SeatTime I have done my test with the gearbox off.

It still does the same thing.

Here is a video



I have had a chat with the supply of the motor and he said that those motors do draw a large current at startup. He usually sells them with a controller that has a soft start function in it and they are usually used as winch motors.

I think that it is just too much for the JRK's.

I am going to put my rig back together and just run as is until I can figure out how to get something like the Roboclaw 2X60A (120A Peak) running with SimTools.

@noorbeast how do I do a resistance check?

Hello,
great work and really nice Simulator.
I've just seen your controll Box with all the elecctrics in. It looks very nice.
May i ask which connectors you have used for the Powercables? Because i can't see at the pictures.

Thanks @tombo

The power cables to the motors? I am using Anderson connectors.

Good to know.

Thanks for the reply,
this Info is also handy, but i mean the screwed connectors on the Box. I took your picture and mark it in red. I hope that is ok.


Because i'm not shure which one to take that can handle the amperage.

@noorbeast @SeatTime Hey guys. Thanks for your help.

I have had a really good night of testing. having the gearbox off and controlling the motor by hand has really helped me understand exactly why this error is happening.

The error happens if you reverse the direction once the motor is at a high enough speed. At slow speeds it doesn't have a problem changing direction. I suspect this it is drawing to much current when it is reversing the motor.

I am wondering if it is because my motors are 5500rpm and most of the motors you guys use are around 3600rpm.

It was really easy to test because it wasn't throwing my whole rig around and I could control exactly what kind of motion I wanted to simulate by hand.

I tried all sorts of settings, none of them really made a difference, I changed the PID down to P=0.2 and lower and it still did it once it was up to speed.

I did find one thing that did fix it and that was to add some brake duration in.

This option sets the duty cycle to zero for a set amount of time before it switches direction. I don't think it would be usable in a motion simulator but it does go to show that the motor must be drawing a lot of current when switching and maybe adding in that pause gives enough time for the motors to settle down before changing direction.

@tombo That connector is not for power. It is for the remote kill switch at the front of my rig. It is a "LTW IP67 Harsh Environment Circular Connector" http://jaycar.co.nz/productView.asp?ID=PP0542

It is only rated at 5 Amps so it is not suitable for carrying power over it, but because my remote kill switch is just triggering a relay then it is perfect for that.

That photo was taken before the big power cables went in. I didn't get any shots after we installed the power cables because it was very cramped in the box. The power cables just come through some IP68 cable glands and directly screw in to the JRK's. I can't remember what size they are, something like this http://jaycar.co.nz/productView.asp?ID=HP0720

The gray Anderson plus I use are rated at 600V 50A do they are pretty heavy duty. I think that is the best way to do it, use a gland then have a big connector outside the box.

5500 prm. Ok , my brikie actuators are 4500rpm direct 1:1 drive.
I slowed the max duty cycle on mine to 250 and max acceleration to 400.
I was able to slow the motors down, but keep some of the power there.

Yeah, If I was to use those settings then it would be totally fine. It is only when I start to go over 300 duty cycles that I get problems. I think 350-400 is a nice balance for me. It is totally fine on the track and it just clips the really violent stuff then I go off track.

If I have friend over and I think they are going to go off track a lot then I will de-tune it to 250 duty cycles

If I tune down my max duty cycle, I can get most of that motion back with a percentage of force change and tuning centre change.

Thanks @bsft Can you give me some more info on how you did this because I would like to play around with these settings.

I go to the JRK utility program, I change the max duty down 20 at a time until it slows a bit, then I go back into tuning centre and reduce the numbers a bit at a time, test it, then if it feels ok, I go to the axis assignments, and increase the percentages up a bit, test, repeat till I find a nice balance.
Ive spent a year, ( with the time I have) working with my brikie actuators and I still do a bit of fiddling. So expect to take some time.
Also remember if you go down the saberetooth path, you will need to run it off an arduino, and best use SMC3 utility, and enjoy endless changing of codes and refining.

@Avenga76 I think you should grab a Kangaroo X2 and Sabertooth 2X60 or something and figure them all out. I have a feeling I will need your expertise once you gain it since I'll probably be in the same boat as you. Bench testing this weekend revealed BIG spikes when reversing directions even with no load much like what you are seeing (using JRK). Ran great otherwise though. Please figure something out for us - haha.

I think these motor's can officially be removed from the "approved" list.

Cool. that is what I have been doing and I am getting good results. I had an amazing testing season last night.

Not sure if I would go the sabertooth route. I am really excited to see if there is a chance to get native support for the RoboClaw 2x60. That is the most exciting one for me

Yes. I would say so, they clearly draw too much current while reversing. I am pretty happy that I have done enough testing to prove this. Both with my results from the scope and from controlling it by hand in my last video (that is actually really fun to do)

I don't think they were ever on the "approved" list (is there even such a list?) I made the call to pick these motors. I thought they would be within spec but there weren't so my bad. It will be too hard to change out motors now because it would involve new lever arms and maybe new motor mounts.

It is running fine now so I can just ignore the errors and keep an eye out for advances on the RoboClaw support

Theres no actual "approved" motor list. What the specs say can be "incorrect". As said, we use things never designed for the abuse we put them through. So we have to expect some faults.
Dont blame yourself for choosing the motors, they work, you just have to look at a different way of controlling them later.