AX10 Glitchy and Runs Out of Steam
 

Hey guys,

I'm a newb to the crawling world. I bought an older used AX10 RTC that functioned fine until I changed the stock 55t motor out for an axial 27t. I ended up putting the 27t in my son's ax10 and switched the old 55t back into mine. Now my truck is really touchy going into reverse. This truck has the ESC that forces you to hit reverse twice before it will go backwards. I have to really tweak the throttle trim to get reverse at all. It still glitches from time to time and the run time has been reduced. It is slower and it has lost significant power. Under WOT the motor sounds like the rpms fluctuate a little. After about 15 minutes it can barely pull itself around. Nothing is getting hot to the touch. I bought a new 6 cell 5000mah nimh stick pack because I thought it might be the old 6 cell split saddle packs going bad but that didn't fix. I'm completely stock. Old AX1 transmitter (not the new 2.4g) and stock ESC and RX. What gives? Any ideas? If I were to replace the ESC and RX with upgraded parts, what should I use and will they work with the old transmitter? I would just buy another motor because that's obvioulsy the cheapest thing to replace but I'm not sure that's my problem. Wait!! It just occurred to me that maybe I got the timing wrong on the motor? Could that cause this? How do you set the timing? Any help would be appreciated.

This may be a stupid suggestion, but are you sure you have the pinion/spur mesh set properly, and the slipper is adjusted?
That may account for your fluctuation in RPM and loss of power when the truck is warmed up...the slipper may be too loose

1-Try recalibrating the ESC to the RX. Throttle trims at "0", EPA's at 100%, then calibrate. See what happens.
2-Depending on the ESC, there may be an "instant reverse" available, look for a manual and see if it's so.
3-If you swap the RX, you really need to swap the TX as well, they won't work together otherwise. AM works with AM, FM works with FM, 2.4ghz works with 2.4GHZ. All these have other limitations, but that is the general. You could look up LosiKids GTB3 hacked radio, it's a 2.4ghz with tons of options for little money. Or try a Futaba 3PM-x or 4PL.
4-Motor timing, maybe it wrong. Is the rig faster in reverse than forward? If so you need to change the timing.
5-Motor maintenance, check the brushes, they may be too short, worn, dirty. Same for the comm (spinney thing inside the motor). Have you lubed the motor bushings/bearings recently?
6-Check for binding in the drivetrain, trans, axles, wheel bearings, etc.
7-Does the ESC have a LVC (low voltage cutoff for LiPO)? It may be on and shutting the ESC down early.
8-Recheck your pinion gear mesh, it may be too tight.

Down the road, you may want to get a LiPO capable charger and some 2S or 3S LiPO's. A 2S LiPO will have a lot more power than your NiMH packs, partly because a 2S LiPO is more like a 7 cell NiMH. You may want to buy just single NiMH cells and add them to your existing packs. I use www.CheapBatteryPacks.com all the time for NiMH & LiPO. Decent prices, no issues and good packs.

1-I've got the old AX-1 setup. The ESC does not have a calibration button
2- No instant reverse option on the AX-1 that I know of.
3- I'll look into a new 2.4g setup.
4- The motor is a cheap novak 55t silver can. I don't think you can change the timing. It goes the same speed in forward or reverse. Reverse may be a little slower.
5-I have not had this motor apart. I have not lubed it either. I simply pulled it out, sat it on the shelf for a day and then put it right back in. What if I changed the orientation when I put it back in ( top screw on the bottom and vice versa). Would that matter?
6-I'll check and report back
7- I don't think the AX-1 has the LIPO cutoff
8- I'll check that. Any tips on getting it right? The slipper has not been tampered with at all so I can't say if it is working properly or not. I would think that if it was too loose the rpms would climb and the truck would not go any faster, right? That's not the case here. Crawler slows and rpm's slow. The rpms match the speed.

Changing the motor mounting won't change the UNLESS you reversed the wiring, then the motor would run in reverse.

I don't believe that motor has adjustable timing, your comment about forward/reverse speed seems to confirm that.

Getting pinion mesh "correct" can be done by placing a strip of regular paper between the gears, then sliding the motor snug against it & tightening the motor screws. When tight, remove the paper, you almost shouldn't see it move but you should sorta feel it.
To gain some more drag brake (keeps the rig from rolling when on an incline) you can close up the mesh a bit more.

If the ESC doesn't have a button it should work similar to castle stuff where you hold full throttle while you turn the ESC on. I think this is where I would start. Should be able to get the manual from Axial's website.

All the above suggestions are good ones for a possible cause. One last suggestion; start with the simple things first; you'd be surprised how many times it winds up being the problem...it's also usually the easiest thing to check

Okay,

I'm not sure what happened but I decided to swap out the motor for a spare 55t motor I had laying around. The rig seems to be working better now. I removed the old motor and plugged it in, holding it in my hand. It had very little speed. When turning the gear by hand it had a "lump-lump" feel to it. I did notice that when I re-istalled the bad motor the first time I had to reverse the throttle on my transmitter to get forward and reverse working correctly. Maybe I ran this motor in reverse and killed it? IDK. I do know that I had it wired white-white and black-black. Why it turned backwards I have no idea. Anyway...spare motor got me back in the game. Thanks for all your help guys!

For a brushed motor, another way to swap rotation is to swap the 2 motor wires."thumbsup"

Does the motor have a preference which way it wants to go and would it hurt anything to reverse the leads? I can't figure out why two times now I've taken a motor out that was red-red and black-black and when I put it back in later the exact same way forward and reverse throttle were reversed. The first time I just reversed the switch on the transmitter. I wasn't sure this was a good plan so I ended up reversing the leads and switching back to N on the transmitter. Which way is better or does it matter? Could this +/- hokey pokey have caused my motor to go bad? I looked a little closer and it's actually a decent quality motor. It's a Novak Fifty-Five. It has timing marks but I never touched them. I'm pretty sure I had the mesh too tight. That may have caused some premature wear I guess. All I know is that on the bench the motor is slow and the rpm's fluctuate under throttle. The motor does not spin freely either. Should it?

Sorry for the newb questions but despite being 43 years old I'm just now cutting my teeth on RC's. FWIW, my six y/o son, Nathan and I have been having a blast with our second-hand AX10's. Nathan got his for his sixth birthday on Nov. 1. I've already bought him a set of HB Sedonas and a 27 turn for his rig. He whips the crap out of me on any obstacle! He lives for RC crawling and watches Youtube crawling vids almost daily. Santa's bringing us both Proline Tuber chassis for our rigs. This looks like a fun father/son hobby for us and I can see us really getting into the crawling thing. I'm glad this forum is here for us. Great knowledge here. Thanks!

Without a pinion gear on the motor, it will spin stiff. Put a pinion gear on and try spinning again, it should spin fairly easily. You may feel a "lumpiness" as the armature passes by the magnets, but it should still spin.
Try lubing the motor bearing/bushing and check again.

If you see the brush braids sticking out of the motor, try gently pulling on them as if to remove the brushes, they should slide easily.

Also check how far the brush spring is in the brush hood slot, there should be room left before you bottom the spring on the hood.

There is a stickie thread at the top of this forum, one thread inside is on motor care, read it.

Yes, it can be a fun hobby. My son & I started with buggies a number of years ago, then he found crawlers spring of 2010. He crawled I drove him to comps. Last CHristmas he built me a 2.2 Bully, so now we both crawl & comp.8)

I started RC around 1976 (gliders), RC cars around 1979, RC racing a couple of years later in 12th & 10th pan cars.

Okay. I found the problem. The old Axial AE-1 tx has a bad throttle pot. If I push the trigger to the side while I pull it back it does fine. Otherwise the throttle is all over the place and slower than it should be. Any ideas on how to replace the pot? What part to use?

am transmitters sell used for $15 or so. no point in wasting time trying to fix one.

id get a 2.4 to start, and a new motor. i never run a motor i got used... they never last. its like buying a new car. if you could get a new motor for $20, why wouldnt you.