Problem burning ibt2

Currently I am building a 3dof. The motors are 24v, 350w geared. With arduino R3 and ibt2. All the connections are per the diagram. When I use ecm3 (I did change to mode 2 for the program to arduino)I follow the instructions step by step with the first motor, and it works fine. I get the first motor to run fine and it runs smooth. When I try to go and set up the second motor, is when the problems begin. It’s runs for about 10-20seconds and it burns not only the ibt2 for the second motor but, also for the first one. I have double checked the connections countless times, I tried different psu, I tried one psu for both motors, separate psu for each motor, all with the same results. The psu are 24v 50amps. I even tried lowering the psu to 20v. I tried the Fpwm a 25 kilohertz and 20 kilohertz. Tried switching motors No difference. When I run it, it has cooling fans, even though I don’t think heating is the problem because when they burn they don’t feel hot. Why do my ibt2 keep burning?

IBT2s are known to burn out at 24V, working configurations that I know of are:
1. 250W motor with a supply of around 18V.
2. two ibt2's wired in parallel.
3. removal of the heatsink and application of thermal paste to the IBT2 + extreme version, sanding down the paint from the areas under the heatsink to better dissipate the heat + thermal paste.
I have burned about 6 ibt2s myself.
I tried 1 and 3 but finally I bought this controller
https://www.xsimulator.net/community/threads/reasonably-priced-100a-motor-controllers.17638/
So far it works fine with 24V 13.4 A 250W motors.
I do not know how it will behave with more powerful motors, theoretically it supports up to 100A but it is however made in china
Mount the KBPC5010 diode on the power supply to protect the power supply from regenerative current.
Do you have one 50A power supply for three motors ?

Thanks for you help , I already tried number 3 , I tried from 17 volts (that’s the lower my psu goes) all the way to 24 volts I do have a psu per motor. I’m not and expert on this but I think if power was and issue when I run a single motor I will see problems already but like I said before the problem is when I connect the second motor to test that burs the ibt2s ,burn then so fast that I’m not even get a chance to Test the second motor.
I was thinking to run each motor with they on arduino ,since I have not problem running just one motor,but how you setup 2 arduinos or 3 with scm3 utility when you can only choose 1 port?

Ok, will try to help.
1. first a description of how it should work: in SMC3Utils there should be two motors working properly without load, other behaviour indicates some kind of bug, hard to find remotely.
2. question how do you test? in my experience turning on square wave or fast movements of manual mode burn IBT2.
3. do the test by switching ‘Sine’ on the lowest possible voltage if again IBT2 fails , again check the wiring.
4.Show your settings in SMC3Utils and exactly what motors you have .

Thanks again for your help.
When I test the the first motor it runs in sine ,in manual in square with load and no load no problems.when I give power to the second motor like I said before I’m not even get a chance to test it because it burns the IBT’s.
The pic of the utility is for motor 1

A hard case
I am running out of ideas.
Looking at the pictures:
- why isn't the green line in the middle and overlapping the purple and blue lines?
below the correct calibration , the other settings are only correct for me, do not suggest them




It's all a bit mysterious , did you swap the motors in place maybe one is faulty and overloading IBT2?
Did you run them directly from the power supply?
Looking at those motors they look the same as my 250W 75 RPM

The green line is not centered with the blue because when I took the pic the rig was in resting position (power off), I did swap motors thinking the same as you but that was not the problem
Yes it looks the same motor the different is my motor is 350watts

Question do you test the motors connected to the seat ?

Yes

Do you know if Can I run an arduino per motor ?

Detach from the seat during testing.
Yes you can easily set up one arduino for each motor for testing in SMC3Utils , each arduino will have a different COM port in Windows, just edit the SMC3Utils.ini file
in the SMC3Utils directory, or make two directories each with a different port entered.
I don't know how to configure it in simtools, where you can only enter one port, so it won't work.
Maybe in FlyPTmover it is possible to set 2DOF on different Arduino.
I use Flyptmover.

Thanks I will try

Problem solved! I bought the motor controllers that you recommended me and now everything works perfect! The ibt2 controllers was my problem they couldn’t handle my motors I guess. Thanks again for your help!