Sabertooth 2x60 serial packet motor driver - oscillation issue

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Hello.

Back in Jan 2019 I purchased a sabertooth 2x60.

The target was to drive two 500w dc motors through arduino for a motion simulator.

I am using a 1200W dc power source in parallel with a 12V battery.

Everything run perfectly fine until 2 days ago. I switched off the pc and the motors started for some seconds and smashed to mechanical stop.

The day after, after resetting the position, The motors started oscillating until hitting the mechanical stop.

I am using SMC3 windows tool to setup the motors and I am using the sketch shared in the link below.

Please see also a couple of vids showing the reproduced issue. I used to have 300Kp and pwm max set at 200. Now at Kp 100 and pwm max 60 it starts to oscillate.

It seems like the motors are driven with some delay with respect to arduino command.

https://drive.google.com/folderview?id=1eddFnKkVWk30mpkYob-QXNhIqhcFq3wa

My setup is exactly as shown in the tutorial.

Using SPS mode with dip switches set to 001111.

I already tried to change usb port and change Arduino board without any success.

Could it be some issues rwlated to Sabertooth?

One additional note:I have a kill switch that “opens” S1 cable. If I push it during oscillation, the motors keep moving until mechanical stop (… And on…).

The sketch automatically enables serial timeout. Why does it not work?

I look forward to receive your feedback/help.

I am electrical engineer, but with very poor digital skills.

I am available for any further info.

Thank you, Best regards,

Paolo

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Hey @pimpi84!

Do you mind sharing the model number of your motors, battery and power supply?

Since you are doing some kind of simulation on the motors, do you think you might’ve gone over it’s duty cycle and let it run for too long?

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Hi @Magmator!
Thx for the reply.
I am in touch with Dimension Engineering.
My sabertooth does not even connect to DEscribe software.
I am sending back as RME for repair.
They think it might have been damaged because of my 7Ah 12v battery I used as sink for regenerative currents.
DE says that for the 2x60 it’s needed at least a 24Ah battery to avoid damage.
I suggested DE to write it clearly in their website.
Hope it helps others…

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That’s good to know, thanks for the feedback.

Dimension Engineering knows their product very well. I suggest that you try to contact them first if you ever encounter another problem like this

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