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Stripping dapu geared hub motor

Featured Replies

Hi, all I am currently stripping my 250w dapu rear hub motor to repair phase wiring.

I have unscrewed the drive side cover and removed the freewheel and planetary gear assembly, however I'm unsure how to remove the main motor assembly.

The images enclosed show that the sun gear assembly won't pass beyond the ring gear.

It seems that the motor must be removed through the opposite side.

However this cover doesn't look to be threaded as I can't see a seam anywhere.

I've enclosed some images of both sides which hopefully show the dilemma.

Any input appreciated.IMG_20210520_195916.thumb.jpg.fe8ca5ba2185b5ebec91e908cb7eed19.jpgIMG_20210520_195903.thumb.jpg.1bd6d59ff6db962a6e0ca133ea31cbbb.jpgIMG_20210520_195903.thumb.jpg.1bd6d59ff6db962a6e0ca133ea31cbbb.jpgIMG_20210520_195916.thumb.jpg.fe8ca5ba2185b5ebec91e908cb7eed19.jpgIMG_20210520_195903.thumb.jpg.1bd6d59ff6db962a6e0ca133ea31cbbb.jpgIMG_20210520_195829.thumb.jpg.ccc02f44967aca779634f271c641f3f3.jpgIMG_20210520_195739.thumb.jpg.5bc5e45d8a20e18bee202575c30f0bcb.jpgIMG_20210520_195648.thumb.jpg.f2ad1216965bcabc7a1481e1372fb908.jpgIMG_20210520_195620.thumb.jpg.f1243e664ebae07cde276912a5684b55.jpgIMG_20210520_195916.thumb.jpg.fe8ca5ba2185b5ebec91e908cb7eed19.jpgIMG_20210520_195829.thumb.jpg.ccc02f44967aca779634f271c641f3f3.jpgIMG_20210520_195739.thumb.jpg.5bc5e45d8a20e18bee202575c30f0bcb.jpg

IMG_20210520_195648.thumb.jpg.7c8d88563a4ff2b9cf519626e2c600a7.jpg

As always, you've taken photos from every angle except the one you need to see the join. It looks like the join is about 3mm in the top outer axial surface before the spokes. heat up the hub between the spokes until iy's just too hot to touch to make it easier to unscrew the side-plate. There's always a chance that it's a left hand thread.

 

Draw a pencil line across the join to see if you make any progress when unscrewing.

Edited by vfr400

The keyways on the hollow axle/motor wire side plate have been mangled, a four keyway spanner is needed to undo the screw thread.
  • Author

The keyways on the hollow axle/motor wire side plate have been mangled, a four keyway spanner is needed to undo the screw thread.

Thanks, logically it should be a right hand thread I assume.

I think the screw joint is as arrowed.

IMG_20210520_195903_LI.thumb.jpg.265fa6398c3b3550100393825a8274bd.jpg

 

 

Vfr thinks it is this one.

IMG_20210520_195903_LI(2).thumb.jpg.61ba68e021229cfcc271551723efff61.jpg

 

Which ever it is the keyweys are where the spanner needs to fit to add pressure/purchase to open it.

Edited by Nealh

I think the screw joint is as arrowed.

 

 

 

Vfr thinks it is this one.

No it's the outer axial surface. Like this one:

DSCN5178.JPG

Edited by vfr400

  • Author

No it's the outer axial surface.

But how would a motor pass through that small opening?

  • Author

But how would a motor pass through that small opening?

It just looks so seamless maybe it's machined after assembly.

The Chinese are very good engineers, the joint appears seamless but is a fine pitched thread. Hence the keyways for a spanner to be used.

But how would a motor pass through that small opening?

What small opening? The openoing is the size of the motor. Look at the photo I just posted.

  • Author

What small opening? The openoing is the size of the motor. Look at the photo I just posted.

Hi, sorry about the confusion.

I don't see any way that cover is threaded and I can't move it either way

It seems as though the motor was put into the casing then the ring gear was sweated on making it almost impossible to remove.

Is that possible, or am I way off here?

Hi, sorry about the confusion.

I don't see any way that cover is threaded and I can't move it either way

It seems as though the motor was put into the casing then the ring gear was sweated on making it almost impossible to remove.

Is that possible, or am I way off here?

 

Off the mark definitely.

 

As mentioned on the side of the hub is the keyway for a 4 keyway spanner to locate a bit of force/torque and it would/should open, unfortunately the keyways have been butchered on your hub so one may not fit or get good purchase.

 

This is similar type of tool you need.

bafang bldc hub engines opening tool for BPM2, SWXK, SWXK5, SWXU-greenbikekit.com online store for e-bike battery, Bafang motor parts, e-bike kit-GreenBikeKit.com

Edited by Nealh

Hi, sorry about the confusion.

I don't see any way that cover is threaded and I can't move it either way

It seems as though the motor was put into the casing then the ring gear was sweated on making it almost impossible to remove.

Is that possible, or am I way off here?

Did you read what I wrote? Am I wasting my time? You didn't respond to any of it!

Did you read what I wrote? Am I wasting my time? You didn't respond to any of it!

 

Some people I'm sure think they know better.

Hi, sorry about the confusion.

I don't see any way that cover is threaded and I can't move it either way

It seems as though the motor was put into the casing then the ring gear was sweated on making it almost impossible to remove.

Is that possible, or am I way off here?

 

Can I ask as to what method you have tried in opening unscrewing the hub side plate ?

  • 3 years later...

I have the same motor. I have been using a hammer and screwdriver but it wont open! I need to repair my power cable.

Did you mange to open the motor? 250w Dapu M123

I have the same motor. I have been using a hammer and screwdriver but it wont open! I need to repair my power cable.

Did you mange to open the motor? 250w Dapu M123

 

The diameter and pitch of the thread pose a significant resistance to tapping with a hammer and you may not be able to deliver a significant enough blow without deforming the head since you concentrating the impact with a blunt chisel.. .

 

What i know as a 'Crank Spanner' or sold as a 'universal spanner' in this amazon ad

819WfY1pFXL._AC_SX679_.jpg

 

Might be a better option with a long steel pipe handle for leverage? If you cant find a suitable tool as linked above.

I have the same motor. I have been using a hammer and screwdriver but it wont open! I need to repair my power cable.

Did you mange to open the motor? 250w Dapu M123

You have to heat up the hub between the spokes with a hot-air gun until it's just too hot to touch. Sometimes these side-plates have left hand threads too. Some motors even have a small pointed grub screw that goes in through the edge to lock the thread, so look out for that too.

 

Draw a pencil line across the join, so that you can see when something moves.

 

Lastly, you can use any sensored motor you want. It doesn't have to be a Dapu one. It'll cost you £15 for a motor cable. You could put that towards a new motor or a used one from Ebay.

Edited by saneagle

  • 1 year later...

I have exactly the same problem with a DAPU M123 RD motor;

 

I opened the right side plate with a 4 keyway spanner , where planetary wheels are, but I can't open the left side where is the cable. The point vfr signed is exactly where it opened on the right side, but on the left side it seams sealed. I passed a screw driver and a knife to look for filing under the painting but I can't see it at all. Forcing with the hammer on the spanner actually resulted in breaking the spanner ring!

IMG_20260227_202217.thumb.jpg.59e11ec6159c992259f5fa78be5801d0.jpg

IMG_20260302_235215.thumb.jpg.f61f79191888119f0a9235600bb07e00.jpg

IMG_20260302_235223.thumb.jpg.271a6efd159c1e6f4becc8292ee37369.jpg

I have exactly the same problem with a DAPU M123 RD motor;

 

I opened the right side plate with a 4 keyway spanner , where planetary wheels are, but I can't open the left side where is the cable. The point vfr signed is exactly where it opened on the right side, but on the left side it seams sealed. I passed a screw driver and a knife to look for filing under the painting but I can't see it at all. Forcing with the hammer on the spanner actually resulted in breaking the spanner ring!

 

One doesn't open the other side, the motor core has to be extracted with a puller to over come the motor winding/magnetic force field ,.

Why not show photos of that side of the motor so that we can help you. You only showed the side that you already solved.

Because the pictures are exactly the same of mrwatt, if not for the pinion thread

 

You can see the signs of screwdriver and knife on outer diameter to look for the gap of the thread under the paint, but with no success (as in the narrower pictures I posted)

IMG_20260302_235156.thumb.jpg.6f0602c19f5c9f71ef27ba7dd26db256.jpg

IMG_20260304_000921.thumb.jpg.be6479ba120d23644766bdeed63e0673.jpg

Edited by mmmx

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