Flipsky Battle Hardened Motor shaft removal and swap.

Looking for anyone who has had to swap a BH motor can/axle and how best to go about that.

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Should be the same as a non BH motor. BH-ing should only be in between the magnets. Shouldnt effect disassembly

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I am talking about how loctited in that grub screw is. What size allen is it even?

Then reassembly and covering the screw again or na? I simply am asking for the same guide as before but showing how to uncover the grub easiest. Any other tips related to the changes in the later revs.

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hey, i don’t quite understand where exactly your problem is? I took my engines apart during the days. What exactly do you need to know

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as I said people have made tutorials but all before the new gen from flipsky with a ton on loctite on the grub.

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Have you done everything now?

Where is the grub screw even located? I’ve never seen one on my bh fs

Underneath the blue dots on the bottom of the can, theyre just buried in loctite.

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Id start with a blow torch

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I disassembled one few weeks ago. Nothing unusual.

  • remove seger ring
  • remove slim rubber ring
  • remove some kind of thin metal sheet washer

and pop it out.

There wasn’t a grub on the shaft?

TIL another name for circlip

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PL Wiki (Seger ring) :

EN Wiki (Circlip):

So yea, there is a few xD

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So the grub screw is buried under this blue gunk somewhere? Shit is super hard. Time to go digging…

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Probably some kind of epoxy. Localized heat (careful not to overheat the magnets) and/or solvent should help. I’ve had decent luck with MEK.

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Well this was a dead end. Let it be known, there is a ~3/8" - 1/2" long plug of adhesive, no grub screw of any kind.

I used my backup iron to melt through rather than hit it with generalized heat and risk damage elsewhere. Took a few minutes of digging, but got through to this:

Thru hole to a cavity on the other side. Will disassemble the stator from the rotor here shortly and investigate further

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That’s odd because I always heard them called “Jesus Rings” in the 1980s and 90s because only Jesus knew how to remove them.

This was before a quick internet search would locate a $10 circlip tool on Amazon.

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Sorry man I honestly thought they would have to secure the shaft to the rotor somewhere but alas, apologies for the wasted time.

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Eh no worries, we all learned something today :slight_smile:

Super interesting to disassemble a brushless outrunner - never pulled one of these apart.

One snap ring + one wave washer, quick pull, easy peasy (thanks @b264 for the guide)

Great coverage across the sensor pcb

I always wondered if the FS-BH motors had the possibility for mounting screws going too deep and shorting on the windings. I tried - it seems like the mounting holes aren’t fully threaded. The fasteners stop right at the edge.


Good epoxy/adhesive on the sensor wires too

Dual bearings top and bottom on the stator, looked in good shape.
For those who may need replacements - NMB R-2210KK made in Thailand.


Confirmed again - no grub screw on the bottom. It’s a bunch of the battle hardening glue packed in the hole. Probably used during assembly somehow.



The reason I tore this one apart is that I have had a high pitched ‘cricket chirp’ sound coming from this motor. I noticed the bell taps the stator at one point, just barely, in every revolution.

I confirmed this - there’s a very slight amount of wiggle to the axle. The bottom of the axle has a hole, which at first glance appears to be a hex head. I tried every allen key I have - metric and imperial - no dice. Upon closer inspection, it is not a hex. It’s a round hole with a lead-in chamfer. My guess is that it’s used to press-fit the axle in place during assembly.

So… now what?! I could try to press the axle out with a hydraulic press, but I’m not sure how I would even fix this. Or how I would line everything up correctly to epoxy it in place.
Orrr I can just take the bell to a belt sander and grind off 2mm and live with it… it works perfect otherwise.

Anyone want to throw an opinion in here?
@Fosterqc you ever get around to swapping shafts?

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