Jittery dual Car ESC - cause?

ESK8 Electronics
1

I recently finished my pneumatics build.

IMG-20170205-WA0000.jpeg2448Ă—3264 915 KB

I am using two HK Car ESCs connected to a GT2B receiver via a y-cable. One of the ESCs however (the one with the cut red wire) is very sensitive causing the motor to jitter when in neutral. I increased the deadband to the maximum value in software but that made no change. Any ideas what I can try?

Also if anybody is wondering: I am using a 6S Lipo and 6S Liions in parallel. Works fine so far

2

try swaping motors/wires to see if its the esc or connection.

this is not a good idea. cells should be identical and balanced. but the super asym motor setup looks interesting…

3

can’t swap receiver cables since I bought the ESC used from a forum member and unfortunately he cut the wire on the ESC side and not on the y-cable. Will swap motors though and get back to you.

They are balanced - I charge them separately outside the enclosure. Also according to this:

it works fine. In parallel I don’t see the issue as long as you take care of them.

The motors are actually set up to result in equal speed via different gearing. The SK3 has a 20/50 ratio and the smaller 140kv Evolve clone has a 15/36 ratio.

4

im using the dual HK Xcar ESC’s and I dont cut any red wire. no jitters here.

5

I’ll try to reconnect the wire then. Would be an easy fix :slight_smile:

6

Ok so I connected the red wire again. First thing I noticed is that now both ESCs turn on and off when I use the switch on one of them - even when the other is turned off. I also connected just the jittery one to the receiver directly and the jitter is also there - so it is not just a problem of the dual config but the actual ESC. Any other ideas? Since it was from a forum member I can’t just send it back.

7

this is normal.

sounds like an ESC problem then. does it work when throttle is applied?

8

Everything works but the neutral position (even after numerous throttle range recalibrations). A small tap on the trigger sometimes makes the jitter stop but returning from like full throttle and releasing the trigger makes the motor jitter then.

9

Did you try to use only one esc and one motor to test the jittering? Someone had a jittery esc before with a dual setup an Y cable. It was gone when he only used one esc for testing. Couldn´t find the thread anymore.

10

Yeah I have tried and used only the jittery ESC (even with differing motors)

11

okok… so the last test i would do is using an other remote to check. If its still jittery, I´d replace that esc with a new one.

12

bad thing is this is a new one I just got from a forum member :cry:

13

hmm thats always bad if you got something and it doesn´t work the way expected. And the forum member didn´t have the same issue with it?

14

I asked him but so far no response

15

So do you have a second remote to check?

16

No - and how can my original ESC work perfectly fine with the same remote when it would have something to do with it?

17

there are sometimes weird problems with some setups and if you change one part, everything works again flawlessly. Sometimes it´s just a marginal different current or different resistance in a part…

18

Might be a stupid question but, Did you do the throttle calibration on both ESC’s?

19

Yeah - several times.

20

well if you swap the esc’s motors your should be able to make sure that its just the one esc that has some issues.

fixing that issue is another question… :thinking:

I have a spare hk120a xcar esc if thats what you are using…