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View Full Version : MR03 VE reverse problem


dameetz
2014.10.11, 12:56 PM
Just got a 2nd VE for myself. Has 2 problems.....

1)when i try to reverse , the car just shake, sometimes it will get to reverse but most of the time it just shake like the current is not enough to power the motor. If i increase the brake EPA, it seems to be better but do not solve the problem completely and it affects my brake adjustment liking (too strong). Even if I bump up the brake epa to maximum, its reverse speed is not as high pitch sound as the forward speed.

2) from standing still if i apply the throttle, the initial movement is not smooth, like its cogs a bit before moving.

My other VE do not have this problem. Only 2 VE cars are having similar problem in my local club (including mine). The ICS and radio setting are the same as my 1st VE.

What i have done so far to rectify the problem:

- WIRING:I have checked all the wiring, found nothing is wrong. I changed the motor wires, the current wires connecting to the terminal but the problem still exist.
-BATT TERMINAL:The battery terminal is the gold plated SP chassis and its still new. I have tighten the screws on the terminals as well.
- MOTOR: change to a known good working motor, still exist.

Any other thing I should be looking for? Anyone with similar problem like mine? Possible the FET is not good?

mleemor60
2014.10.11, 03:28 PM
Seems you tried everything but a fresh set of batteries. Insufficient voltage will create a low speed reverse as well as cogging going forward.

dwight
2014.10.11, 05:11 PM
I had that problem to after I program it the car worked fine

dameetz
2014.10.11, 10:52 PM
Seems you tried everything but a fresh set of batteries. Insufficient voltage will create a low speed reverse as well as cogging going forward.

Tried freshly charged batteries too, problem still exist.

dameetz
2014.10.11, 10:54 PM
I had that problem to after I program it the car worked fine

You mean program by ICS? Can you share it pls...

El Tigre
2014.10.14, 09:18 AM
Have you tried re-binding the radio to car? I have had quirky issues that clear up with a rebind of the radio/car. Make sure radio batteries are good too.

dameetz
2014.10.14, 12:26 PM
Changed the motor to PN brushless and the problem is gone. Apparently the stock Orion motor has some issues.

dameetz
2014.10.20, 01:03 PM
After few days working fine now the problem came back, the PN motor still installed, tried few different motors that I know are working fine with my other VE....the problem still exist....so the stock motor that I mentioned earlier must has been fine.....I m running out of ideas on what to do now.....could it be the FETs are defect? Has anyone tried to replace the VE fets? Are the they the same type as brush motor fets?

TheSteve
2014.10.20, 01:10 PM
I would think it is a solder connection issue somewhere. Fets themselves will never be intermittent, they either work or they don't. It is also possibly a radio issue, not all MiniZ's have the same neutral point - some are very picky.

dameetz
2014.10.20, 01:34 PM
I would think it is a solder connection issue somewhere. Fets themselves will never be intermittent, they either work or they don't. It is also possibly a radio issue, not all MiniZ's have the same neutral point - some are very picky.

I already tested with different radio last time and its still there. Can you suggest where to look for for a possible solder connection issue? I just re-soldered the motor wires, check and clean the batt connection terminal, tighten the screws as well without any success on solving the problem.

Let me try to explain again the problem, when I put on the gas, the car jerks a bit and move forward, when I do reverse the car just jerks/shaking, sometime it will go to reverse but most of the time it will only jerk. Compare it to my other VE, the forward movement is really smooth and so is the reverse function. From my view as if the ESC is not giving enough current to drive the motor or possibly only 2 phase of 3 phase needed to drive the motor are working thus why i m suspecting the FETs.

Also as you mentioned, if it has Neutral issue, how do I adjust it? Can the board be calibrated like the normal big scale esc?

Thanks for helping, i m willing to try anything to solve this problem.

Kay-Dee
2014.10.20, 01:52 PM
Hy

Have you tried to program the ESC ?
Use the same settings from the cars which works fine !

dameetz
2014.10.20, 01:59 PM
Hy

Have you tried to program the ESC ?
Use the same settings from the cars which works fine !

Done that already, exactly the same setting as my other VE.

TheSteve
2014.10.20, 02:10 PM
I have seen your exact problem before and I am sure it was a connection issue. The reverse just sort of pulses because the VE chassis has very low power in reverse. Forward will cog/hesitate a little.
Make sure the positive tabs on the batteries are making proper contact and aren't just barely making contact because of some interfering plastic.
I have also seen the exact problem with bad batteries.

Either way it is always a lack of voltage getting to the electronics.

KWT
2014.10.20, 11:17 PM
Have you contacted Kyosho? They could repair it for you if the car is still in warranty.

dameetz
2014.10.21, 02:29 AM
We don't have an actual Kyosho distributor here in my country, only hobby shops and most if not all are not warranted. I have just done replacing all the wiring to the motor and from the batt to the board, clean the gold plated terminals and sand the contact tab which is screw together from the terminal (would direct soldering these improve the current flow?) I ll be testing it again later at the track and report back here if the problem is gone or not.

dameetz
2014.10.21, 11:00 AM
Ok just got back from the track.....the car is better but the problem is not 100% gone. The cog/pulse is still present when throttling up but not as worse as before. Now it can do reverse all the time at least tonight but the initial movement is not as smooth still has little cog/pulse for half a second before moving. Overall i would say it improved a lot though the problem is still there.

One thing I notice with this car was it is punchier and faster than my other VE (the smooth one). I tested it back to back a few times, comparing between the two. Both use PN 7500kv motor and same batteries same gearing. The smooth VE can only maintain the punch about 3 mins of continuous hard drive after that it will soften and maintain the speed while the problematic VE can maintain punch and speed about 5-6mins. I have yet to swap the motors between the two maybe I try that tomorrow. So i guess its a give and take thing.

So far I m happy about the improvement and hopefully the problem will not come back again, though the cog/pulse is still present at least it can go to reverse all the time, I could live with that.