I finally broke down and purchased a UBEC.....it runs so smooth now.....before I was running a 5 cell 1400 mah rx pack....now with this I have zero cogging even @ slow speeds.......it just added more wires to the mess... but not much....

Hey guys - I'm resurrecting this thread again...

I tried the receiver pack finally tonight and it does the exact same thing - hesitates to respond to throttle input under all sorts of distance and speeds. Actually, I think it ran worse with the receiver pack but I could be wrong.

So back to the UBEC - should I try it mounted in some different positions?

Is there anything else I should consider testing out? I think I'm going to try a different radio just for kicks. I run spektrum (for now) so I wouldn't think that would be the issue but you never know.

Thanks again,

Steve

Id try mounting in different positions, i run a spektrum too and no problems. You run a switch right? What is your bracket made of? aluminum? That could also cause an interference.

Did you try mounting the ubec with the flat side toward the electronics? The board is the shield, That's what the directions told me.

It's hard to tell from the picture; but is your receiver right behind the controller? can you get a more detailed picture?

Did you tried re programming your controller? and you did removed the BEC jumper from the 9920?

I use sponge foam to seperate the reciever away from the metal and the UBEC. Stopped the interference I was having. So they sit on foam, instead of aluminium. ;)

Was an opinion. :024:

Well if you have tried rx pack and ubec. You went thru and checked all your connectors and made sure they got good connection. I would check with different batteries as well to see how they would do. If all this don't help and moving the rx don't help. If you can would or could you try another esc?

I don't have a switch. I probably should, but I thought it would just add more wiring to the confusion.

One of my initial thoughts regarding the ubec was the quality of my soldering on those tiny wires. I had a less than a fun time getting them soldered on to the deans tabs with the other, fatter wires. But since I have the same problem without the UBEC in place, I'm assuming that wasn't the issue.

The controller and the motor connection is what I'm starting to think is problematic. The controller sits on the chassis, attached with industrial velcro, right behind the front shock tower and perpendicular to the drive line. Its just barely out from underneath the motor. I will experiment with some alternative locations on the controller.

The other area I'm not sure about is the motor to controller. If you've ever seen an uninstalled 1940 7 turn hi amp, the back of the motor has three separate solid strands of copper winding coming out of it about a half inch or so. No preinstalled plugs. For flexibilty, I soldered on some 3.5mm plugs onto the ends of these wires and heat shrinked the plug and the exposed wire. Then I soldered plugs onto the controller and made the connections. I found over time that one or two of the 3.5mm plugs seemed a little loose, so I used some electrical tape to try better hold the plugs together.

I guess this was a long way of saying I think this motor was designed to be direct wired. Do you guys think, given my problem, that it might be worth undoing my motor connections and direct soldering?

I would get the meter out and check the resistance of all solder connections to make sure they are good.

Nl - alright, I'm showing my electric ignorance. What do I need to do this (specific name of tool?), how do I do the test, and what is the expected result?

Thanks for the help!

I have the same problems with mine. 9920, hmmm, i would also like to do this test!

Okay, now that I thought about it for a second I believe nl12 is referring to getting out an ohm meter.

Anyone care to describe how to use an ohm meter to test soldered rc connections (motor plugs, deans plugs, etc...)?

here are my questions again.
 

and again..

A normal meter isn't capable of measuring contact resistance bytheway.

Serum - I'll take some detailed pics tonight. The receiver (and the receiver pack or ubec) is at the opposite end of the truck from the controller, near the rear shock tower. The controller is at the front. Both are mounted using velcro to try and isolate them from the aluminum chassis. I have removed (and have always had it removed) the black bec jumper on the underside of the controller (near the programming jumper).

I have not tried re-programming but I should be able to try that tonight as well.

So is there no way to test the quality of a solder join as nl12 suggests?

A bad solder joint wouldn't result in the problem that you have. It would show under hard acceleration.