Building a 4DOF from the SK3 kit provided by Simukit

@Stacy Sammons thanks. It would have been great if it works! I purchased the pro simtools to test it but nothing moved. I checked the output from the psu and it showed 0v. When I took the psu out of the rig and played with its potentiometer setting then it would jump to 20v. But if I let it sits for a few minutes then the voltage started to drop to 0v. I made a video and sent it to Simukit and they are looking into it. They seem to think that the psu has a selector switch but as you can see from the picture the selector switch is missing.

So I am now completely stuck.

Simukit was able to contact their power supplier about my 20v problem. Their provider sent a soldering modification for the power supply (see picture). I followed this mod and was able to get the proper power output of 24v. This is a painful problem to fix since I had to remove the psu from the frame and disassemble the power supplies to do the soldering and reassemble the thing again into its frame. The process took several hours as it wasn't easy to take the psu board out of the enclosure.

Hi all,

I have downloaded simtools to try to test the motor outputs but there was absolutely no movement on the motors. If you have some idea where I did wrong, please give me some help.

Here are the things that I have done:

1. I connected the arduino and sabertooths and motors according to this tutorial from Simukit (https://drive.google.com/file/d/1ddeGoTkdeAshr1772pSLyEZbYTr2YisF/view). You can see the schematic in the attached picture.

2. download and install the sabertooth arduino library at https://www.dimensionengineering.com/info/arduino. The software is called "Arduino Libraries for SyRen/Sabertooth Serial (includes examples)
v1.5 by Dimension Engineering"

3. download and install the arduino sketch called XPID_SimTools1_6_6motors_2x32_serial_Micro.ino at https://drive.google.com/file/d/0B8IoIAW9JuhPVl9FLXpqdFZDaHc/view

4. connect the computer to the arduino using usb port and uploaded the code. Code was uploaded successfully.

5. installed program Describe (https://www.dimensionengineering.com/info/describe).

6. connect the computer to the sabertooth using usb port and use Describe in 5. to upload the new config parameters to the sabertooth, i.e., setting the current limit to 40A and baud rate to 115200.

7. download and install Simtools Pro. Set Axis Assignments, interface setting as in the attached pictures, make sure that the com port is that of the arduino.

8. In Simtools output testing, I tried to change the values of Roll, Pitch and Heave but nothing happened. There was just no movement on the motors.

This testing is a critical stage of my built, if anyone can give me some light to get it working, it will be very much appreciated. I am especially looking toward @yobuddy , @jjanu and @axenic who have done it before to give me some leads.

Thank you all.

Thanks @yobuddy for pointing that out. I added the parameter for output rate and it still didn't move. The pictures show my new configuration.

I checked the power supply to the sabertooth boards and that showed 24v. I checked the signals from the arduino and they are connected. I checked the output from sabertooth to the motor and it always show 0V. I am not sure what else to check at this point.

Oh joy! @yobuddy , I got some MOTION now after double checking the connection of the signals from the arduino to the sabertooth boards.

My problem now is that I got too much motion on motor 1 & 3. They always seem to move together constantly. The motors became fairly hot after a while so I had to shut them down. Video https://drive.google.com/file/d/1fmurELmJGw_8oGrqBb2OoaO4YOUt3DVg/view?usp=drivesdk

I still have no clue on how to set the axis assignment and interface setting.

You were asking about the interface output, I got the interface output setting from the simukit tutoriel's link (http://pcshm-simulateurs-homemade.c...s-nouveaux-explication-lien-sch-ma.htm#p61163). Here is the quote from it:

"et ici l'écran de simtools comme il devrait être rempli (VALABLE EGALEMENT JUSQU A 4 MOTEURS):

la ligne de code est : X1<Axis1a>CX2<Axis2a>CX3<Axis3a>CX4<Axis4a>C
"

I changed the Output Testing setting from "DOF Output" to "(a) Axis Output" as you have recommended but I still see motors 1 and 3 move together.

I am not sure of where to go from here yet. Please give me some lead.

@yobuddy , the motors move without me doing anything.

Since I only have 3 motors, I did change the string to have only 3 axis as you have suggested: X1<Axis1a>CX2<Axis2a>CX3<Axis3a>CX4<Axis4a>C . That didn't have any effect on the motion of the motors.

@noorbeast, I have just emailed Simukit for assistance. I am hoping that it is just a software problem like a config setting or a wrong arduino sketch.

@yobuddy, I checked my wiring again and the potentiometer return signals were not connected to the correct a0,a1,a2 input ports on the arduino.

For example the potentiometer return for motor 1 supposed to go to a0. Instead it was connected to a1.

I made the necessary adjustment thinking that it would work finally but two of the motors would shake back and forth constantly. Video https://drive.google.com/file/d/1SxG4Og-NHgUQ0paAwAyVxuG7KeyoKKbf/view?usp=drivesdk

Have anybody seen this before?

Are These both Motors on the Same Sabertooth ? If yes i Had it when i build Mine .. Had to Change plus and minus on one Pot ... If i remember correct

@Ringorumble , these are motor 1 and 3, they are on different sabertooth cards. Motor 2 doesn't shake and seems to respond well to Axis Testing from Simtools.

I am still waiting to hear from Simukit on the problem.

@yobuddy thank you for the lead on the alternate arduino sketch. Look like it needs an UNO board which I don't have at the moment.

I tried to diagnos the problem by writing a sketch to read the pots' inputs and the values look reasonable over different pot setting (see picture). I am beginning to think that either the sabertooth library has a problem or the sabertooth/arduino boards have a problem. I still have not heard from Simukit support yet.

Great joy after the following great piece of advice from @jjanu. I was able to follow it and motors are no longer shaking. Every motor is working like it should now.

Sadly it looks like my motion platform still not working well yet. One of the three motors consistently alternate between seemingly working normal and then violent burst of spin. At first I thought that the pot for that motor was faulty so I replaced it with a new one. However the result remained the same.

Have any body encountered this problem before? Please give me some idea on how to fix it. Thanks.

Video of a normal working rig https://drive.google.com/file/d/1rRKzAREwXDuxi3gffxgaCJq5TelA2EVO/view?usp=drivesdk

Video of a burst of motor violence https://drive.google.com/file/d/1mbxt3ktmdWAHaQwfhgaM-XsIGXijFps7/view?usp=drivesdk