Viewing post history: Converting a hubmotor to a middrivemotor

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This page shows all versions of the post, starting with the most current version.

Current post: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over mounting a sprocket to the hub (rather than the axle) for using it as a middrive:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase in torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power (by a so called "thermal bridge" / heatbridge)
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor (edit: I know now it's about triple without additional heatsink).

Warning1! The peak output power is NOT influenced by this conversion. If you could drive your Hub@1kW for a minute, that does not mean you can drive it with 3kW after conversion! But you can drive it with 1kW continuously without overheating it.

Warning2! You might think now that you could still double your output power by changing the plastic gears for metal ones, this is true, but high torque leads to low efficiency due saturation of the magnetic path in the motor! This is why I do not recommend using metal gears. I simply replace my plastic gears once in a year, they are cheap and run much more quiet.

Warning3! Up-Speeding your motor does raise output power, but it has limits. As a rule of thumb, 250Hz field-change-frequency should not be exceeded for motors with 0.5mm laminations, since eddy current loss raises a lot at higher rpm. This means you should not run your rotor faster than:
*1000rpm for the older MAC, 2000rpm for newer 0.33mm lamination motors, as well as the BMC hubmotor which are identically constructed
*2000rpm for the Bafang BPM
*1750rpm for the Bafang SWXB and SWXH
[/color]

EDIT: the conversion described below was abandoned, since I developed a much better one (read second post) this text below just shows how this idea was born. The first succesfull conversion like that was done on a used and very cheap Bafang SWXB front hub motor, but can be done with many others as well or even better

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub (by a so called "thermal bridge" / heatbridge)
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics (graphic found on pg 22):
Attachments
2012-11-04_15-04-43_599.jpg
2012-11-04_15-04-43_599.jpg (79.9 KiB) Viewed 27271 times
2012-11-04_15-09-45_914.jpg
2012-11-04_15-09-45_914.jpg (98.9 KiB) Viewed 27271 times
2012-11-04_15-27-18_541.jpg
2012-11-04_15-27-18_541.jpg (95.17 KiB) Viewed 27271 times
2012-11-04_16-35-11_294.jpg
2012-11-04_16-35-11_294.jpg (71.16 KiB) Viewed 27271 times
2012-11-04_16-36-37_683.jpg
2012-11-04_16-36-37_683.jpg (58.85 KiB) Viewed 27271 times
2012-11-04_17-47-51_454.jpg
2012-11-04_17-47-51_454.jpg (83.97 KiB) Viewed 27271 times
2012-11-04_17-59-48_904.jpg
2012-11-04_17-59-48_904.jpg (98.4 KiB) Viewed 27271 times
Edited by spinningmagnets on Mon Sep 08, 2014 9:39 am.
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Revision 13: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over mounting a sprocket to the hub (rather than the axle) for using it as a middrive:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase in torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power (by a so called "thermal bridge" / heatbridge)
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor (edit: I know now it's about triple without additional heatsink).

Warning1! The peak output power is NOT influenced by this conversion. If you could drive your Hub@1kW for a minute, that does not mean you can drive it with 3kW after conversion! But you can drive it with 1kW continuously without overheating it.

Warning2! You might think now that you could still double your output power by changing the plastic gears for metal ones, this is true, but high torque leads to low efficiency due saturation of the magnetic path in the motor! This is why I do not recommend using metal gears. I simply replace my plastic gears once in a year, they are cheap and run much more quiet.

Warning3! Up-Speeding your motor does raise output power, but it has limits. As a rule of thumb, 250Hz field-change-frequency should not be exceeded for motors with 0.5mm laminations, since eddy current loss raises a lot at higher rpm. This means you should not run your rotor faster than:
*1000rpm for the older MAC, 2000rpm for newer 0.33mm lamination motors, as well as the BMC hubmotor which are identically constructed
*2000rpm for the Bafang BPM
*1750rpm for the Bafang SWXB and SWXH
[/color]

EDIT: the conversion described below was abandoned, since I developed a much better one (read second post) this text below just shows how this idea was born. The first succesfull conversion like that was done on a used and very cheap Bafang SWXB front hub motor, but can be done with many others as well or even better

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub (by a so called "thermal bridge" / heatbridge)
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Attachments
explosion_2.png
explosion_2.png (159.48 KiB) Viewed 24345 times
remove_key.jpg
remove_key.jpg (64.84 KiB) Viewed 24345 times
Edited by crossbreak on Mon Apr 07, 2014 1:36 am.
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Revision 12: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over mounting a sprocket to the hub (rather than the axle) for using it as a middrive:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power (by a so called "thermal bridge" / heatbridge)
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor (edit: I know now it's about triple without additional heatsink).

Warning1! The peak output power is NOT influenced by this conversion. If you could drive your Hub@1kW for a minute, that does not mean you can drive it with 3kW after conversion! But you can drive it with 1kW continuously without overheating it.

Warning2! You might think now that you could still double your output power by changing the plastic gears for metal ones, this is true, but high torque leads to low efficiency due saturation of the magnetic path in the motor! This is why I do not recommend using metal gears. I simply replace my plastic gears once in a year, they are cheap and run much more quiet.

Warning3! Up-Speeding your motor does raise output power, but it has limits. As a rule of thumb, 250Hz field-change-frequency should not be exceeded for motors with 0.5mm laminations, since eddy current loss raises a lot at higher rpm. This means you should not run your rotor faster than:
*1000rpm for the older MAC, 2000rpm for newer 0.33mm lamination motors, as well as the BMC hubmotor which are identically constructed
*2000rpm for the Bafang BPM
*1750rpm for the Bafang SWXB and SWXH
[/color]

EDIT: the conversion described below was abandoned, since I developed a much better one (read second post) this text below just shows how this idea was born. The first succesfull conversion like that was done on a used and very cheap Bafang SWXB front hub motor, but can be done with many others as well or even better

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub (by a so called "thermal bridge" / heatbridge)
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Wed Dec 04, 2013 7:54 am.
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Revision 11: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over mounting a sprocket to the hub (rather than the axle) for using it as a middrive:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power (by a so called "thermal bridge" / heatbridge)
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor (edit: I know now it's about triple without additional heatsink).

Warning1! The peak output power is NOT influenced by this conversion. If you could drive your Hub@1kW for a minute, that does not mean you can drive it with 3kW after conversion! But you can drive it with 1kW continuously without overheating it.

Warning2! You might think now that you could still double your output power by changing the plastic gears for metal ones, this is true, but high torque leads to low efficiency due saturation of the magnetic path in the motor! This is why I do not recommend using metal gears. I simply replace my plastic gears once in a year, they are cheap and run much more quiet.

Warning3! Up-Speeding your motor does raise output power, but it has limits. As a rule of thumb, 250Hz field-change-frequency should not be exceeded for motors with 0.5mm laminations, since eddy current loss raises a lot at higher rpm. This means you should not run your rotor faster than:
*1000rpm for the MAC
*2000rpm for the Bafang BPM
*1750rpm for the Bafang SWXB and SWXH
[/color]

EDIT: the conversion described below was abandoned, since I developed a much better one (read second post) this text below just shows how this idea was born. The first succesfull conversion like that was done on a used and very cheap Bafang SWXB front hub motor, but can be done with many others as well or even better

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub (by a so called "thermal bridge" / heatbridge)
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Thu Apr 18, 2013 1:41 am.
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Revision 10: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over mounting a sprocket to the hub (rather than the axle) for using it as a middrive:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power (by a so called "thermal bridge" / heatbridge)
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor (edit: I know now it's about triple without additional heatsink).

EDIT: the conversion described below was abandoned, since I developed a much better one (read second post) this text below just shows how this idea was born. The first succesfull conversion like that was done on a used and very cheap Bafang SWXB front hub motor, but can be done with many others as well or even better

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub (by a so called "thermal bridge" / heatbridge)
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Mon Feb 04, 2013 9:26 pm.
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Revision 9: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power (by a so called "thermal bridge" / heatbridge)
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

EDIT: the conversion described below was abandoned, since I developed a much better one, see second post, this text below just shows how this idea was born

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub (by a so called "thermal bridge" / heatbridge)
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Thu Jan 31, 2013 8:25 pm.
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Revision 8: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power (by a so called "thermal bridge" / heatbridge)
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

EDIT: the conversion described in this first post was abandoned, since I developed a much better one, see second post, this text below just shows how this idea was born

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub (by a so called "thermal bridge" / heatbridge)
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Sat Jan 26, 2013 1:08 pm.
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Revision 7: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

EDIT: the conversion described in this first post was abandoned, since I developed a much better one, see second post, this text below just shows how this idea was born

To achieve this,
1.the phase wires are cut and pulled out of the axle
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a brass guide pin and a brass washer
4.the left side axle is shortened
5.the stator is screwed to the hub
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Sat Dec 29, 2012 10:38 pm.
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Revision 6: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

EDIT: the conversion described in this first post was abandoned, since I developed a much better one, see second post, this text below just shows how this idea was born

To achieve this,
1.the phase wires are cut and pulled out of the axle (pic2)
2.the axle is cut through behind the planetary gear (pic1,3-6)
3.the "new" output shaft is centered by a brass guide pin and a brass washer (pic 7-14)
4.the left side axle is shortened (pic15 and 16)
5.the stator is screwed to the hub
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Fri Dec 28, 2012 12:26 am.
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Revision 5: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

To achieve this,
1.the phase wires are cut and pulled out of the axle (pic2)
2.the axle is cut through behind the planetary gear (pic1,3-6)
3.the "new" output shaft is centered by a brass guide pin and a brass washer (pic 7-14)
4.the left side axle is shortened (pic15 and 16)
5.the stator is screwed to the hub
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Thu Dec 27, 2012 11:28 pm.
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crossbreak
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Revision 4: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 . The mod is ONLY possible with outrunner geared hubmotors.

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame (to get a light, rigid and NOT ugly looking mount)
-the heat produced by the stator can be conducted to the hub to increase cooling and so the continuous power
-possibility of using sprockets with less than 18 teeth (to speed up the motor and thus raise power and efficiency)

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

To achieve this,
1.the phase wires are cut and pulled out of the axle (pic2)
2.the axle is cut through behind the planetary gear (pic1,3-6)
3.the "new" output shaft is centered by a brass guide pin and a brass washer (pic 7-14)
4.the left side axle is shortened (pic15 and 16)
5.the stator is screwed to the hub
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Sun Nov 04, 2012 9:03 pm.
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crossbreak
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100 MW
 
Posts: 2799
Joined: Tue Aug 02, 2011 11:20 am
Location: Germany

Revision 3: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 .

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit to the frame
-the heat produced by the stator can be conducted to the hub to increase cooling and continuous power
-possibility of using sprockets with less than 18 teeth

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

To achieve this,
1.the phase wires are cut and pulled out of the axle (pic2)
2.the axle is cut through behind the planetary gear (pic1,3-6)
3.the "new" output shaft is centered by a brass guide pin and a brass washer (pic 7-14)
4.the left side axle is shortened (pic15 and 16)
5.the stator is screwed to the hub
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two, three and four done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
Edited by crossbreak on Sun Nov 04, 2012 8:39 pm.
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crossbreak
100 MW
100 MW
 
Posts: 2799
Joined: Tue Aug 02, 2011 11:20 am
Location: Germany

Revision 2: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 .

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit on the frame
-the heat produced by the stator can be conducted to the hub to increase cooling and continuous power
-possibility of using sprockets with less than 18 teeth

The aim is to achieve the double continuous output power of a regular mid-mounted geared hub motor.

To achieve this,
1.the phase wires are cut and pulled out of the axle (pic2)
2.the axle is cut through behind the planetary gear (pic1,3-6)
3.the "new" output shaft is centered by a brass guide pin and a brass washer (pic 7-14)
4.the left side axle is shortened (pic15 and 16)
5.the stator is screwed to the hub
6.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two and three done. The remaining points will follow next sunday. I needed no special tools for the mod, except for a brass cartridge and a 15mm inner dia pipe from the hardware store. I used my lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill, a file and sand paper. Enough talk, here are some pics:
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Edited by crossbreak on Sun Nov 04, 2012 8:24 pm.
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crossbreak
100 MW
100 MW
 
Posts: 2799
Joined: Tue Aug 02, 2011 11:20 am
Location: Germany

Revision 1: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W front driving MBG Goldenmotor for this mod (reviewed the 36V rear version here http://endless-sphere.com/forums/viewtopic.php?f=3&t=4892&p=654910#p652141 .

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit on the frame
-the heat produced by the stator can be conducted to the hub to increase cooling and continuous power

To archive this,
1.the phase wires are cut
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a guide pin
4.the stator is screwed to the hub
5.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two and three done. The remaining points will follow next sunday. I needed no special tools for the mod, but I used a lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill. Enough talk, here are some pics:
Edited by crossbreak on Sun Nov 04, 2012 7:39 pm.
User avatar
crossbreak
100 MW
100 MW
 
Posts: 2799
Joined: Tue Aug 02, 2011 11:20 am
Location: Germany

Original post: Converting a hubmotor to a middrivemotor

Postby crossbreak » Sun Nov 04, 2012 7:28 pm

Hi folks,

The idea is to use the axle of a geared hubmotor as output shaft. No one ever did post anything about this in the past ( I searched a lot), that's why I wanna show how it might work. I use a 24V 250W MBG Goldenmotor for this mod.

This mod has some advantages over just mounting a sprocket to the hub:

-the gear ratio of the hub gear is increased by one (original: 4:1, modded: 5:1, that's an increase of torque of 25%)
-the hub can be used to mount the motor unit on the frame
-the heat produced by the stator can be conducted to the hub to increase cooling and continuous power

To archive this,
1.the phase wires are cut
2.the axle is cut through behind the planetary gear
3.the "new" output shaft is centered by a guide pin
4.the stator is screwed to the hub
5.the "new" output shaft gets another bearing on the output side of the hub (this is necessarily to not over stress the guide pin)

Today I worked 3 hours and got point one, two and three done. The remaining points will follow next sunday. I needed no special tools for the mod, but I used a lathe to get a better result for the output shaft. It could possibly also be done with an ordinary hand drill. Enough talk, here are some pics:
User avatar
crossbreak
100 MW
100 MW
 
Posts: 2799
Joined: Tue Aug 02, 2011 11:20 am
Location: Germany

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