I'm getting ANGRY!

[Bulldog]

Ok,

I have two HH BRXLs I've used them here and there and they always worked fine. I have one setup right now to a tekin 35t pro. I'm running a CCBEC running into the bind port of a Futaba RX (using a futaba 3pm). From what harley says, the futaba RX can handle the voltage. The red wire is removed from the esc going into the throttle channel.

The problem...everything is working fine. I've recalibrated it numerous times and checked the field link. I've got a ton of fresh new batteries. The issue I'm having is that from a dead stop, I have no power going to the rig. If I give it a little kick start by pushing it, it works fine. It's doing it in forward and reverse. I've checked throttle trims, and played with about every adjustment I can. I've reversed the power wires and reversed the throttle...same deal. Can anyone think of what's going on?

This is really frying my chip. Thanks in advance and happy fourth!

[Charlie-III]

First...happy 4th of July....thank a vet if you want to.
Second, sounds like a motor issue. It's called "armature stall", basically a winding is shorted. If the motor has a brush that falls on the bad winding, the motor is "dead". A slight movement of the rig moves the motor so the brushes are on the 2 working windings.
Testing (with a meter) will likely NOT show an issue.
Either replacing the motor, or, the armature is the only easy way to fix the issue.
I can rewind the armature, but that is a bit beyond most people here.

Let us know, but I'm willing to bet that is your issue.

[JokersWild]

Yup or com is bad/ dirty or distroyed

[Jus]

Make sure the brushes are making good contact with the comm. A hung brush will do what you're describing. I've had it happen after running in really dusty/sandy conditions.

[Postclanker]

Originally Posted by Jus

Make sure the brushes are making good contact with the comm. A hung brush will do what you're describing. I've had it happen after running in really dusty/sandy conditions.

Plus 2....take the brush wire out a little with the spring still attached and let it "pop" back into the the comm...or change your brushes.

If you know what a comm cleaner is, polish up the comm and the brush...my bet is your problems go away

[Bulldog]

This particular motor only has about four hours of run time... So a hung brush or debri sounds possible. Thanks for the ideas guys! I'll check things out and let you know where I end up. Fireworks time!!! And yes...think of those who have served and are in the bad part of the world right now away from their families!

[Postclanker]

I've seen brushes break right out of the box....granted, not with a high quality motor...just saying

Check it out....just might be the problem

[Bulldog]

So here's a little surprise surprise. I think we found the issue.




So obviously the brushes are gone. I just read this from JRH regarding premature brush wear. Sounds right...but a lot of things don't apply.

"Try advancing the timing to 12 degrees and using a softer spring to increase your wear. Below 7 ounce springs tend to arc, stay above that rate. Stay away from water too. If you have a BRXL turn off hold mode. If you are using 3s lipo, realize you are putting almost double the voltage to your motor as compared to racing days. If you are at zero timing, add some for a happy motor.


The lower the motor resistance, the faster a brush will wear on a given voltage. 27t wears faster than 35t, 55t slower than 45t. Handwounds wear faster than machine wounds. 55t machine wound motors can be run for years with just a little care and clean running.


The biggest wear factor is all about the person on the throttle. I have seen kids wear down brushes in 30 minutes on my rig when I just got done putting 10 hours through a set. Forward to reverse action eats them fast, and is something you would never come across in racing use/abuse."

So my side of the story is a TEKIN PRO (handwound) that hasn't seen a drop of water, run for four hours without ZERO drag brake or forward to reverse. Yes, it was run on 3s. I never even thought to check the brushes on this one because of the time. So I'm guessing a comm cut is necessary and new brushes. Or stick to my brushless setups. If anyone has anything to add by looking at the pics and words...let me know. Thanks in advance for any ideas. Greg

[SINister]

I don't know if your going to be able to cut that comm it looks pretty bad. Hard to tell from the pics but it looks like it's burnt almost all the way through the copper. Hopefully Eddie or John will see this thread and give you their opinion on it.

[EeePee]

Thankfully, I'm not John or Eddie, but in my opinion, that thing is done. It'll take 20 passes to smooth that out again, and there won't be much left. Got calipers? Check the middle.

Four hours of use and that brush being that gone is not normal.

[TEDROCKZ]

I think that brush broke a way before it got to that point. Then what was left of the brush wedged it's self back against the comm and reseated all funky and bound then caused some bad heat and arcing issues. Long story short a new arm is in order. That thing is done

[65BAJA]

Just curious but what does the other side brush look like?

[Bulldog]

Originally Posted by 65BAJA

Just curious but what does the other side brush look like?

Exactly the same. I'm just scratching my head. I've got plenty of other motors with way more time on them. I can understand if I put a lot of pain on the motor, but I'm a scale driver. And when I say four hours on this motor...that's being generous. Maybe three packs of 2200mah and filming the video in my sig. Half the time I was setting up cameras and such. Blasting in the loose dirt and not a bind to be found, just doesn't add up. Any other ideas? I'd agree, the comm looks cooked. I'll get a caliper measurement...but for a "Quality motor"...I'm pretty surprised (disappointed).

[EddieO]

Arm is done....no way a cut is gonna fix that. You need a new arm, brushes....can probably needs a zap.

I don't think the brush broke, it honestly looks like it wore down to that.

Without the motor in front of me, it could of been a host of things that caused it. Can I see the rest of the armature? Windings and such.

I must ask, what truck and gearing was it run at? Was there a motor in the truck before this one? If so, what and what was it geared at.

Later EddieO

[Postclanker]

I'm surprised that ran at all...even after kick starting it

[trig n tahoe]

kickstart LOL

[Charlie-III]

I can't say I recall brushes that short...... they usually quit working before that.

As mentioned, yep, I believe that arm is done. New arm with brushes a cheap way to go while improving the performance (provided the magnets didn't get hot).

[Bulldog]

Ok,

Major User error is starting to heat up. After swapping transmissions around and not paying attention, I had a wraith tranny running 80/20 gearing. At one point I lost a pinion and threw a 24 on there and forgot about it It had the spur cover on as well. So this gearing on a 9lb rig is definitely the kicker.


Here are the pics of the arm and measurement of the comm. 9.74MM



So not being familiar with replacements, does it make more sense to get new guts and spend money on shipping or just turn it into a paperweight?

[65BAJA]

Wow. It got hot enough to sling the solder off where the windings attach to the comm. You should either send the motor in for a rebuild so they can zap the can or just get a new motor.

[Zeks05]

Id Hit John or Eddio up for a new custom arm... and reuse ur case and grap some new brush and springs... maybe bearings too coz it looks like it got really hott lol.