2DOF Motor Problem solved with post #3741

[Hoschi]

hi

for my 2DOF Simulator I am using two 24VDC motors with 500W power.

But these motors are no worm motors like the most here use. They are normal DC motors.

The problem is:

When I sit in my racing seat, the 2 motors can only move the simulator from the lowest to the highest position if I make a extreme full-power configuration.
But I cannot use this configuration for the simulation of racing games cause no exact positionig can be done so. Its way too hard and too much shaking.
If I use a more smooth configuration the motors wont have enough power to move the system (with a person) in a proper way.

I tried every possible configuration (all posible dymanic speed configurations, different math inputs, etc.) but nothing worked well.

So my question is:
Should I go on and search for the best configuration or is my motor not made for doing these minimal movements. I mean, the movement from the lowest to the highest point isnt even 1 turn for the motor and these motors are build to run at a max. of 480 rpm. So they cannot give the power they have at this slow speed??
I dont know if I am on the wrong way or there may be a solution. Please help me. Thanks!

[motiondave]

what controller are you using?

[x1610]

what kind of gearbox are you using
Tell us more or post some picters

[Hoschi]

I use this motor : http://shop.mat-con.net/epages/62158737.sf/de_DE/?ObjectPath=/Shops/62158737/Products/my1020z2
and my control is a Sabertooth Dual 25A but that is not the problem here.
I knew that using this motor for a 2DOF would be a tricky thing, but I thought it wouldnt be so powerless.
The motor has a gerbox but that does not change the fact that its not suited for a 2DOF.
I'll have to buy a wiper motor, or what do you think? And what type?

[motiondave]

You have said what motor drivers you are using, but what about the control board for it?
Is it a AMC, Arduino?
What feedback setup do you have?
Can you post pictures of your setup so we can see and advise?

Perhaps do not go shopping for other motors till we establish the problem here first.
But if you are looking at motors, http://www.motiondynamics.com.au/worm-d ... -180w.html guys here use them to great success.

[Hoschi]

The controller is a PC, or in other words the X-Sim Software, with a Vellemann IO Board.
As "encoder" I use a 10k Potentiometer.
This setup is nothing special and for sure not the problem. Most of the users use s.th. like this.
Also my power supply has a max of 500W.

For 99% I am sure, the motor is not suited for that purpose. I also haven't seen a similar motor in other projects without a proper gearbox. I could install a external gearbox but I think a all in one worm/wiper motor is the best solution. I will buy one...

[motiondave]

which vellman IO is it?
K8055? K8061?
I have used motors without a gear box.
I built a sim with one gear of a winch gear setup, so it spun at nearly 400 rpm. 200w 12v, but I controlled it with Pololu JRK.

[x1610]

Hi
Because its a freewheeling gearbox,it could be torque loss made by PWM.

[motiondave]

Hi
Because its a freewheeling gearbox,it could be torque loss made by PWM.

True, they are rated at 12.5nm or torque, but still a 6-8nm wiper will shift a well balanced frame.

[Hoschi]

I use a K8055N. It has a better sampling time than the older Velleman Boards.

Without weight the system is moving "correctly" . But t's not 100% stable and a little bit shaking, even in a smooth configuration. But this would be ok for me. Its like a motor vibrations of a real car.
With weight (75kg person), the motor can only move out of horizontal position. At the endpoint there is no way back (only if I give full speed with nearly 100% dynamic speed in the other direction, but then the speed is too high to be stopped at a certain postion again. This will end in a completly unstable, loud and shaking system).

The motors are at the lower back of the seats. They are ca. 60cm away from the center. Ok I could move them more away from the center, but if it will not work with 60cm , s.th. is wrong and it wouldn't be so much better if the distance is higher. In other 2DOFs the distance is even more less.

Sure an external controller would be better. But I dont think thats the problem here. In a lot of other projects there is also used the same HW, K8055N and a sabertooth 24V. So this should not be the problem.

As the worm motor mentioned above isnt't available in Germany, I will try to get this ones: http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=150899640238&ssPageName=ADME:X:DERP:DE:1123