How To: Fix cogging problem on Lehner ESC´s

[Mr. Constructor]

hi there, after having some trouble with these LEHNER ESC´s again and again (mostly the warrior series and several others too) most people tend to use a battery pack for the rx and shut off the BEC on the controller.

Here´s a new Version that is easier to make and use (as the place needed for it will be lot smaller):

buy a 1000 nF max. 16 V condensator and solder a red/black wire to it (shrink the wires at the solder points !!) and put a small servo type connector to it (the same than your servo maybe futaba or JR) and put the wires in the same position as the plus and minus on the servos.
(check out the capacitor/condensator it has a marked plus side (some have marked minus) so you know the solder direction)

this Unit connects to a free rx channel (NOT the bec connection port !!) to get the juice from the esc, the capacitor/condensator will now "puffer" a little extra energy for coming over the voltage low spikes that cause the cogging problem when going from zero to full in a hurry or having cogging due to bad gear selection.

You could try smaller capacitors/condensators if you like, they´re faster "filled" but don´t go under 220 nF (it´ll be too small)

Good Luck on testing this out !!

[glassdoctor]

Sounds like the old "stutter stoppers" I think Novak might still have something like that.

[starluckrc]

Yes....and the info is posted on BK's site now as well.

[bob2300NX]

Starluck: where is this on there site. I looked but could not find it.

[FninjaP90]

So this will make a Lehner ESC as smooth as a Uforce75?

[rstnboy]

I just looked at BK's web page and found the information. Their information conflicts with what Mr Constructor posted on one small detail. The capacitor they list is 1000 uF (micro farad) whereas Mr Constructor says to use 1000 nF (nano farad). The 1000 uF sounds as though it would be the one to use.

Mr Constructor - can you clarify? Thanks.

[bob2300NX]

rstnboy: Could you post a link to this info??????

[rstnboy]

http://www.bk-electronics.com/bk_eng.html

Then move your cursor over the speed control towards the upper right side. A small test box will pop up saying "Controller Programming Step by Step." Move your cursor over this box and a menu will appear on the left side. The capacitor info is listed under "Further information."

[666yeti666]

rstnboy,
you are correct that it has to be a 1000uF capacitor, a factor 1000 larger than a 1000nF.
However, I just tried a capacitor of 4700uF on the free rx connector and it didn't work out !


I'm using it on a lehner micro1895 and a basic 5300 in a 2 wheel drive duratrax evader truck with masher 2000 tires (18 pinion, 88 spur) with a 6 cell sanyo 2400 pack.

Maybe it does work out on a warrior controller, but to be honest, I doubt it very strong ....
What do you think the extra capacitors on the controller are needed for ....

[Mr. Constructor]

sorry got that mixed up was too fast with my fingers, yes it should be MICRO farad, nano would be any effect either off course !!

i found it a good idea, but as general, the software itself isn´t that good than hacker or schulze, so this is only small fix, to fix the biggest problem at all !!

as a cheap car esc it really is a try esp. in the 12 cell class, but when using 6 go for a hacker or schulze !!

[bob2300NX]

Thanx rstnboy!

[OpIvy]

666yeti666 on www.offroad-cult.org tried it, and it didn't work..
-Nick

[666yeti666]

bob,
did it work ???

[OpIvy]

oh, 666yeti666 is on these boards too lol.
sry, I didn't see your post.
-Nick

[bob2300NX]

666yeti666: I can not try it because my esc went bad and is on its way to BK.

[666yeti666]

bob,
did you fry it ...
Maybe I should not say it, but I'm not really charmed from the BK guys. I've had some email conversation with them about the cogging problem, but it seems someone answers that doesn't know where he's talking about, no engineer for sure.
He just drops things that can done, but without technical explanation for it. Just as the thing with the capacitor on the rx.
On the other hand, brushless in cars is still pioneering I think.

what controller do you have ?

[bob2300NX]

I had the warrior 7018. It fryed in like 4 days so it was falty.