Senton 3s blx lost 3 motors

[Cheapbastard]

Yep I could not find it either. Yes 5mm.

Motor bearings I guess.

Yep 5X13X4mm are the motor bearings size.

 

[SrC]

Tear down that motor and press out the old bearings, press in new. Easier said than done. But can be done for sure. A new set of motor bearings really make the motor like new again. Make sure to lube the bearings. Don't depend on what's in them as new.

 

[t_MoneyCR250]

Yep 5X13X4mm are the motor bearings size.

Ok I will clean out the old motor and use it as a spare. A lot of dust in there from spur gear getting rounded off.

 

[rabidsquirrel]

There definitely seems to be a design or materials issues with the Senton 3s motor mount/bulkhead assembly. My nephew’s Senton eats spur gears and motors within a handful of sessions at the Lake Park, Florida track. There’s too much flex in that assembly between the pinion and spur gear/slipper clutch assembly. I’m on the third motor, third spur and pinion gears. It really sucks as the rest of the truck is pretty good. I was going to pick up a second one to run with him, but this motor bulkhead issue has scared me off of doing that. I used to race 1/8th scale buggies. I don’t really crash and he’s not had any big crashes with it either. He’s been really careful with it in fact. We’ve only really run it together. Probably less than 5 packs worth of run time. I know how to set gear mesh. I’ve even set it slightly looser which seemed to give us more run time between failure(s).
The nylon/plastic clutch shroud assembly seems to be the culprit, allowing for too much flex. I’m not sure if there’s an aftermarket fix for this other than a full metal assembly...

 

[slick2500]

There definitely seems to be a design or materials issues with the Senton 3s motor mount/bulkhead assembly. My nephew’s Senton eats spur gears and motors within a handful of sessions at the Lake Park, Florida track. There’s too much flex in that assembly between the pinion and spur gear/slipper clutch assembly. I’m on the third motor, third spur and pinion gears. It really sucks as the rest of the truck is pretty good. I was going to pick up a second one to run with him, but this motor bulkhead issue has scared me off of doing that. I used to race 1/8th scale buggies. I don’t really crash and he’s not had any big crashes with it either. He’s been really careful with it in fact. We’ve only really run it together. Probably less than 5 packs worth of run time. I know how to set gear mesh. I’ve even set it slightly looser which seemed to give us more run time between failure(s).
The nylon/plastic clutch shroud assembly seems to be the culprit, allowing for too much flex. I’m not sure if there’s an aftermarket fix for this other than a full metal assembly...

If the motor is eating the bearings the mesh gets out of whack and that is probably what is destroying the spurs. The simplest fix we have found for dirt getting into the motor module is this https://www.arrmaforum.com/threads/3200kv-blx-3660-motor-bearings.9826/#post-367654

This could eliminate the flex that you are experiencing https://m2cracing.net/arrma/583-m2c-3160-arrma-17mm-hub-extenders.html

 

[rabidsquirrel]

That M2C brace is definitely a possible solution. Best potential solution I’ve seen so far. Thanks for the heads up!
FWIW - Dirt entering the mount housing hasn’t been an issue in our case. Nylon dust from the spur gear being eaten by the flex between pinion and spur gear/slipper clutch builds up in the assembly over time. It may be a slight contributing factor to the motor failures, but I believe the root cause is the flex itself. Lateral pressure on Motor shaft from the aforementioned flex is destroying the front bearing and motor. There is always a bit of play in the motor shaft when we swap out the failed motors...

 

[rabidsquirrel]

Bought the M2C motor mount/brace. I should be able to run it at the track sometime tomorrow. Installed it and it seems promising.

 

[rabidsquirrel]

OK. Ran the Senton 3S through 4-5 packs today before it ate the spur gear. Oddly enough, this represents a significant lifespan improvement, so I’d say that the M2C Racing motor mount and brace are a success.

I was getting a little over a pack outta of the stock setup before gears were toast.

now I’m going to slap the HD steel spur gear in there to see how long that lasts with the M2C Racing setup. Should be much better...

 

[Puddlejumpernva]

It definitely sounds like you know what you're doing but I feel like there's something else at play here for your spur gear issue. Like maybe the slipper adjustment or hub damage? Drag in the diff or some seized bearing somewhere else in the drivetrain?

I've had similar issues with my v3 Big Rock. I pulled the trigger on the M2C mount and brace but haven't got around to the install. My motor was flexing enough to crack the chassis below the aft part of the can. I stuffed some support material under there, seemed to help.

Horizon actually replaced my slipper hub and threw in a few plastic spurs when my Spektrum motor locked up and seized my drivetrain. Offered to replace the bent motor mount plate too but I had already bought a Hot Racing one.

Let us know how it goes please!

 

[rabidsquirrel]

Yeah, there is probably some other contributing factor, but a 4x lifespan improvement of the gears is significant in my opinion.

I did detect some lateral play in the motor driveshaft, so it is also on its way to failure and it’s brand new. Did a warranty swap in the store for the original stock motor, b/c I’ve been waiting on the replacement motor from Arrma since January.

I haven’t disassembled brushless motor cans before, otherwise I would attempt to swap out the front motor bearing... it’s probably pretty straightforward, but I don’t feel like potentially voiding the warranty and/or making it worse. I’ll just swap it again when it fails I guess.

every time I replace the gears I check and clean the driveline bearings. Soak in solvent, blow ‘em out and spin them up, then rinse them again and repeat. Then I’ll give them a drop of bearing oil and spin them up/blow out again. Pretty much my SOP.
However... This disassembly revealed that the front slipper clutch bearing had completely come unglued as well. Tiny ball bearings fell out of the power model as I removed it.
ordered some replacement bearings and awaiting their delivery.

 

[rabidsquirrel]

OK, gang, the M2C brace for the Senton 3s is the real deal. Definitely helping the spur gear (Nylon), pinion and front motor bearing last a lot longer! I’m probably getting 15-20 packs (Track use) through a set now - I’m resetting/readjusting the mesh every 5 packs or so. I think this setup is ready to race now. I just need to source a good 2s Lipo or LiFe battery for racing.

BTW/FYI - the composite pivot balls that come with the kit are basically garbage after 15 packs on a track, so find the hot racing aluminum replacement kit at your earliest convenience. If anyone happens to know the measurement (Size) of the suspension arm pivot balls, I’m all ears! I can’t seem to find the sizing info anywhere online and I’m too lazy to pull out the calipers/experiment to figure out if another manufacturer’s pivot balls are a direct replacement.

Figured out how to disassemble the motors, clean them and replace the bearings by watching YouTube vids. It’s pretty easy to do, but the can screws are super easy to strip, so be really careful!