Guys I need help!
 

I just finished my Mugen MRX-3 BL conversion and I am having a serious issue. On the bench it winds up quite nicely, but, once on the ground it barely moves. The motor direction is right, the end points on the radio is maxed out, I trippled checked the esc settings...I am at a loss. I did move the spektrum rx to this car from another car but all I did was change model info on radio so that should not matter.

The car rolls freely on the ground with out power being applied. Any ideas would be helpful

Set up:

2 5K Zippy 25C 3S packs in series for 6S
1518 1800kv It is all I had to test with...a 2600kv will go in later
Spektrum 3S

MMM esc settings:
low start power
70% punch
70% brake
10% drag brake
0 timing
3.3v cutoff
Reverse lock out

I once fried a LMT and it would behave like that. This is a new motor tho? IDK, are you sure everything works correctly separately?

Connections...

I will go back and recheck them tomorrow..thanks. Yes the motor is brand new

Yes everything worked before installing into car

Yeah sounds like a faulty plug somewhere. :yes:

Well. I reconnected it to castle link did an update and it goes like the wind...however, when I pull the trigger now it crawls along for 3 seconds and then...WOW it takes off like a rocket w/out warning. Trying to figure out how to get rid of the delay..any ideas

Did you recalibrate the radio after the update?

what would I calibrate on the DX3s? I have gone over and over the radio looking for some way to get rid of the lag in throttle response

Errr, to the MMM, I meant. Endpoint calibration... Sorry... :oops:

Recalibrate the ESC to the radio as if it were a new ESC (full throttle, brake, neutral).

I will try that tonight...thanks

I believe I figured it out...after looking through someone else's on road build I realize I forgot to JB weld the spur to the shaft. It slips just enough before it engages. hopefully this will fix the issue

lol..

Funny how the simple things can really trip you up

So true...not only trip you up but drive you crazy until the little light bulb goes off in your head:yes:

Im glad you got it sorted, I bet that thing rips :whip:

You didn't say the motor was spinning fine... :lol: Glad you got it figured out.

Not so fast all..upon others and myself looking closer, the 2 way bearing is not engaging as I apply throttle. It will engage after a few seconds though...so my question is this. If I JB weld the two way bearing to the shaft so it will not spin will it hold and work?

I'm assuming you mean the one way bearing in the 2 speed? Never heard of a 2 way bearing. Most one ways have rollers that grip the shaft in one direction and are installed on the 2nd gear of a 2 speed. 1st gear is usually locked to the shaft. Can you just use the 1st gear spur?

Jb weld might work. I'd be concerned about the JB being able to grip the smooth shaft and any grease in the one way contaminating the JB. So personally I'd try degreasing the one way bearing as best I can and maybe rough up the shaft where it sits a little.

Can we get some pics of the beasty?

Edit: If you are using the stock 2nd gear spur there is another issue to think about. Even afer locking the one way bearing to the shaft, there is still the actual shift mechanism. This is usually a "pawl" type system that uses centrifugal force to engage. Even with the one way locked to the shaft, until the shaft and the pawl is spinning fast enough, it wont engage the 2nd gear spur and drive the car. From your initial post this sounds like the most likely scenario.

I do believe we have a winner here....I will look into first gear as the more I think about it, the more it makes sense.....crap that means repositioning the motor mount.:diablo:

I will get pics up tomorrow morning as well. thanks a bunch for your help

See a little nitro knowledge goes a long way in the electric world! :lol:

I'd see what you can do about locking it into 2nd gear before reengineering your motor mount. I never paid much attention to all the revo conversion threads, but since the shifting mechanism should be similar, might be a good place to start and get some ideas about locking it into 2nd.