Stripping dapu geared hub motor

mr watts

Pedelecer
Jun 4, 2020
49
0
64
sheffield uk
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.jpgIMG_20210520_195903.jpgIMG_20210520_195903.jpgIMG_20210520_195916.jpgIMG_20210520_195903.jpgIMG_20210520_195829.jpgIMG_20210520_195739.jpgIMG_20210520_195648.jpgIMG_20210520_195620.jpgIMG_20210520_195916.jpgIMG_20210520_195829.jpgIMG_20210520_195739.jpg
 

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vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
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.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
The keyways on the hollow axle/motor wire side plate have been mangled, a four keyway spanner is needed to undo the screw thread.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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I think the screw joint is as arrowed.
IMG_20210520_195903_LI.jpg


Vfr thinks it is this one.
IMG_20210520_195903_LI (2).jpg

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

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Aug 7, 2014
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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.
 

mr watts

Pedelecer
Jun 4, 2020
49
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64
sheffield uk
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?
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
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West Sx RH
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
 
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vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
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Basildon
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!
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
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West Sx RH
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.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,917
8,533
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West Sx RH
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 ?
 

bigdrago

Just Joined
Jul 5, 2024
1
0
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
 

thelarkbox

Esteemed Pedelecer
Aug 23, 2023
1,209
371
oxon
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


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

saneagle

Esteemed Pedelecer
Oct 10, 2010
6,814
3,151
Telford
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.
 
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