Dealing with Com-Port errors

[yokoyoko]

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Hi,

some of you may know - I struggeled alot with com-port errors in the past. After some hints of sirnoname and an "eye-opening" aha moment with my load cell for brake-pedal I finally got the sollution.

I've tried alot of things before!
- usb isolator / galvanical seperation for every usb connection
- One Usb Port per Motor
- Ferrit Cores for the wiring to motor
- Shielded "expensive" Usb Cabels for the JRK's
- Different Position of wires, boards and Pc
- Caps inside the motor for "noise cancelling"
- Used a usb port monitoring software to see what is going on
- stuff I blocked out

You can read about this issue in this post too --> http://www.x-sim.de/forum/viewtopic.php?f=19&t=302&p=2139&hilit=com+ports#p2139

All this trials had no effect on the com-ports errors - or the effect was rather random and not reproducible...

The solution that helped me alot is to "isolate" the motors completely of the frame. My rig is made of aluminium and electrically conducting.
I can't really explain the phenomenon why the com port errors appear - but I think it has to do with induction which is disturbing the usb part of the JRK's.

Notice that the wipers were treated to not lead the ground through the case and this was tested this way:

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(Thx BobBuilt for the grafic)

But like said above - some induction during using these motors in combination with a conducting rig (and mounting to the motors) is not a good idea. I realized this because of my load cell (also mounted to the rig) was disturbed while x-sim and the motors were running (small [mV] changes).

For solving this problem I completely isolated every motor and all parts connected to the motors.
Like this: (picture will be edited)

I used a 1mm "ABS" plate - but you can use every isolating material. I "sandwiched" my motor-mount with this plastic. Additional you have to take care that the hole/drilling for the mounting screws is isolated too. Therefor I used a plastictube with a fitting diameter. In my case 8mm inside 10mm outside. The tube is cutted to the height of the motor mount and placed in the drilling.

After you have done this you can test if you were sucessful - I used a cheap multimeter. Very easy with the continuity tester - which is part of the most multimeters.

Best regards
yokoyoko

[motiondave]

well done dude, you got that right, islolate the motor earth, especially wipers.

[prodigy]

Well done fixing your problem.

I've had the same problem with motor isolation, in the end I didn't want to change my frame parts like you did, I've bought another wiper instead
But that one wasn't so good either

[yokoyoko]

For solving this problem I completely isolated every motor and all parts connected to the motors.
Like this:

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I've had the same problem with motor isolation .... I've bought another wiper instead

Hi prodigy - I don't think it is necessary to buy different wipers and sorting out the one that work. I think you have done the "ground mod"? If it is done successful there is no grantee if you have a conductive frame/rig that there will be no comport errors using the jrk's. (just on my experience - I hope Martin will write something here with some electrical background ^^)
"Ground mod" (see also BobBuilt's pic above!):

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Forget about the comments in the pictures. I tried everything -> with caps, without caps, different "size" of caps, ferrit cores etc.... Just get sure that there is no Ground or Potential comming through the case of your motors.

In my experience it is still necessary to isolate the motors of an electrical conductive frame!

Tested with many differnet wipers (Vw golf 3+4, Audi a6 4b, ....) -> all bosch-numbers in a same range AND the ZYT90 motors.

Best regards yoko

[motiondave]

How about just buy some good motors like the motion dynamics or ebay daytons. They are already earth isolated. Not to mention faster, more powerful and bigger than wipers.
I understand if you already have wipers for a very cheap price and you can fix them, then go ahead and use them.

[yokoyoko]

How about just buy some good motors like the motion dynamics or ebay daytons.

Do you have a copy and paste key for this on your keyboard?

....AND the ZYT90 motors

In my post I said that i own also the ZYT90 - most common more powerful alternative here - and NO I am not willing to import standard dc motors from australia...

The wipers are the cheapest = for beginners best diy possibilty = worldwide affordable. Even SCN5 users are very pleased with the motion of my current wiper setup. The "naked" motor is not the only important part of a great motion sim.

I mentioned that the errors are related to the conductive frame - no specific problem to the wipers. If you buy the ZYT90 with an aluminium gearbox housing you deal with the same probs. Many users use the "cheaper" Plastic housings of the MCP4 - so probably no problems ... (or the rig is of wood, or who knows...)

[prodigy]

If you buy the ZYT90 with an aluminium gearbox housing you deal with the same probs. Many users use the "cheaper" Plastic housings of the MCP4 - so probably no problems

I didn't know that, is that really so?
I thought that they have good isolation and that aluminium boxes are just stronger version than plastic ones..

Good that I've ordered plastic housing then..

[ScottSim]

Hi guys'
great thread and some good descriptions that assist in fault finding, I understand in this instance the COM port errers were intermittent.
In my instance the error, was an unable to open comport error as well but having never ussied xsim , thoght it was windows or my settings.
I did not think the usb cable could have been the isue, but after checking and checking software and set up (as a noob) I replaced usb cables and my drama was over. (Jrk software ran fine )

Oh well at least I know my motor earths are good

Cheers

[motiondave]

If you buy the ZYT90 with an aluminium gearbox housing you deal with the same probs. Many users use the "cheaper" Plastic housings of the MCP4 - so probably no problems

I didn't know that, is that really so?
I thought that they have good isolation and that aluminium boxes are just stronger version than plastic ones..

Good that I've ordered plastic housing then..

Thats weird, I have cast aluminium casing and gearboxes on my motors, no earthing problems at all.