ICE CRUSHER | 16ply HOLYPRO | 4W chain drive MTB | 4x 6374 170kV APS | quad ESCAPE | Steering damper

I read about this problem several times, but only on APS motors. It seems, that they had or have a problem with their glue or glueing process. Jenso broke 4 APS motors within a few days. I tried to fix them: broke all magnets out, cleaned them, cleaned the bell and glued them back in. I tried this several times with different glues but had no luck. They always came loose again.

I hope you have better luck with yours, but you should maybe lower your motor amps until you get your replacement bells.

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I‘ll upload some pictures after my New Years vacation which started today :wink:

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That’s I interesting to hear. Thx for your input, very much appreciate that. I had a small talk with bruno from aps and he said that they had this issue before but solved it on newer motors by applying more or different glue. But he also said that that should have been on the motors I have. However, I noticed a big difference in how the magnets on the 6374 motors glued in, compaired to the 6384. on the 6374 motors you can der that there is some epoxy or other glue even around the magnets. On the 84 motors that’s not the case. I wonder why especially the APS motors have that. If you say you tried different glues it maybe could be the material they use on the bells. Maybe the metal part expand faster or something like this and with it the epoxy get lose from the magnets or can’t hold the magnets anymore.

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Have anyone tried using green loctite to glue the magnets back in? My guess is that the loctite should be strong enough to keep the magnets in place, however the heat of the motors might be an issue…

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As far as I know @Kug3lis used green loctite to glue his magnets back in on the 6384 motors. As my magnets already totally broken I can’t glue them back with loctite. Honestly I applied some green loctite inbetween of the magnets in hope it will fill out some parts which maybe not glued properly. Buuut as we can see that didn’t do the job in my case.

Last update was that I broke some magnets in some of my motors. That´s why I decided to “battle harden” the bells of all the still working motors. I´m very tired from this picture: IMG_7651 It´s already the third motor and this way is my last hope to get this motors work more reliable. But what is battle harden? Battle harden means to fill all gaps in the motor with epoxy. this way the magnets are more strong fixed and should withstand even an impact. It´s mainly used for fight robotic stuff. What do you need?

  • Epoxy (maybe also some thickener for your epoxy)
  • some wooden sticks
  • heat shrink big enough to cover the motor shaft
  • cups for mixing
  • lots of papers
  • gloves if you want

How it works? If you too lazy to read through, watch this video:

In the description you will also find some product information. As I sourced all my stuff locally I´ll not link anything. The epoxy I use is a 4min epoxy used for motor and car stuff. For me it has the perfect consistence. It´s fluent but still thick enough to don´t run away from the holes.

First you need to take appart the bell from the stator. Than you want to remove the shaft. As this might be not comfortable for most of us, you can just cover the shaft with heat schrink in the right size. You really don´t want to get some epoxy on the motor shaft. If you work on an old motor it makes sense to clean first the bell and make sure everything is dry before you continue to apply the epoxy. Depending on how fast your epoxy is getting dry and how fluent it is, you will need to mix up more or less epoxy. For me it worked best doing 3 lines than clean up everything, wait 3-4 min and continue with the next 3 lines. If you mixed up the epoxy you fill the space between the magnets with it. Probably your magnets will be covered with some epoxy too. Use the wooden sticks to clean the magnets as good as possible. Repeat this till all your magnets glued in and it looks like this or better :wink:

It´s recommended to let the bells sit like this as min one day. During this time I had a look at the stator too. Here you could do the same with all windings. It could probably help if you have a slightly lose winding or strange high pitch noice coming out of the motor at a specific speed. I for my own deceided that it´s not really necessary. One thing I didn’t like on the motors, that the phase wires are pressed to the housing. In this place the windings also soldered to the flex awg cable. I have seen pictures of broken/cut isolation exactly in this place, that´s why I decided to cover this place with epoxy too and restrict the cable moving to like zero.

If you do this too, take care that the phase wires are in the right angle coming out of the motor. If they stay up too much it´s not possible to mount your motor later :sweat_smile: One more thing you could do in the same time, cover the sensors and pcb with some lack or epoxy too. waterproofing your hall sensors can save you from a lot of troubles.

Ok, so it´s time to put everything together again. Turn the bell with your hand and make sure nothing is rubbing. if it is, some 500 sandpaper can help to get rid of this.

I also recommend to do a new motor detection after you assembled everything back, to make sure everything works how it should.

Happy riding!

For now I could test the battle harden motors only on the bench. Still waiting for one replacement bell for the 6374 motors. If all this was worth the work will be reviewed in one of the next updates here.

@Riako finally made it to write everything down :wink:

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Definetly something I’ll wanna do when I start building, if it works its worth the hassle over the cost and time of a broken magnet

Good writeup!!

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I know that @sender made the same with his dark matter motors. I think it looks even better on his motors :sweat_smile: I really hate to work with epoxy :joy: I don´t know if he already had a time to take them for a ride but he said that they spin way much more silent and accurate after this modification.Aas min on the bench.

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Wow, thank you so much to write all this with the detailed process and photo Andy !! It’s awesome !!! I will do this on my APS 8072 for sure :wink: :+1: For now, I don’t have any question or misunderstanding :slight_smile: (I haven’t watched the video yet but I think I will need to do some on the stator too). Hop, Ice Crusher Bookmarked! Looking forward to your updates !!

Big Up Andy :v:

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Thx! The video is super detailed. With it you will know exactly what to do and how to do it. Good luck with your APS8072.

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Awesome write up! I was going to, but I will just be linking this instead!

Bookmarked!

Thanks @Andy87

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I hope I didn´t forgot anything. If you have a time I would be happy if you could post here 1-2 of your pictures. Your motors look way much batter made than mine.

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20181208_181323 20181216_095519 20181216_095515 20181216_090939 20181216_084014

Here are a few. I thought I had more, but I can’t find em

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looks very good! thx!

Great thread thanks, gonna try this battle hardening

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Should have updated this… it’s already a pretty long time ago since I was driving last time. I had to wait super long for the replacement bell and vacation and other things just didn’t gave me a lot of free time. But let’s update some things I done on the board since the last time. I removed all cans and battle harden them. I also fixed the phase wires with epoxy on the place where they leave the motor.

On my last ride I had the issues that one of the xt90 plugs came lose. That could happen as the wires from the battery to the vesc box are pretty tight and fixed on the bindings. The movement of my foot caused the xt90 to get slightly lose which resulted in a power reduction of the back motors. As i didn’t wanted to make new cables I made one xt90s extension plug. Easy peasy and problem should be solved with it.

  • this place is left free for pictures when I can upload again :sweat_smile: *

I also cleaned the chains. They now shiny and smooth like new :relieved:

Over time one tire lost air. Seems to be a very small leakage as the tire hold a good pressure for about a week after filling it up. Need to see how that goes when I drive more often. Luckily I have a spare inner tube on hand, just in case.

So, all in all the board is ready to go again. Just need to find a time to take it out.

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man great content! I will do it to the motor I am making. They are already disassembled so easy peasy. Whihc epoxy do you suggest for doing it? A high temperature one I guess.

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I bought epoxy which used for motor parts in cars etc. It’s local Russian production :sweat_smile: so i can’t tell you any European equivalent. Just take care that it’s not too fluent. It’s not nice to work with if it is. Best consistency is like warm peanut butter :stuck_out_tongue_winking_eye: Like this it’s flowing nice in the gaps and you can easy take away the epoxy which came on the magnets. 5min dry time is optimal. 3-4 gaps, clean up everything, wait 2min than go on with the next 3-4 gaps.

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What about using an insert and a low viscosity epoxy and ‘cast’ the magnets and wires into solid blocks? I imagine it has better grip and weight balance