Typhoon kits - my way to convert Bafang BPMII to middrive

E

evb

10 W
Joined
Apr 29, 2010
Messages
74
Location
Russia
In August 2013 I read crossbreak's topic about converting geared hub motor to middrive and decided to do it. Spent a lot of money for buy lathe, drill machine, band saw etc. And a year later I finished it. Its name is Typhoon :)

Now I suggest short pics manual for repeat my way to get a power middrive kit ( 70+km/h max speed)

I. Disassembly





II. Assembly

1. Alloy hub
material: aluminum 2024-T3
weight: 25g


2. Small thermal bridge
material: alloy
weight: 18g


3.Large thermal bridge
material: alloy
weight: 72g
thickness: 3mm


4.Silicon compound thermal conductive pads
thermal conductivity: 4W/m·K
thickness: 1mm


[youtube]iaxkQC2Fejk[/youtube]

We invented an another way to make the shaft. It's more reliable and can withstand high power.
The shaft consists of two pieces joined thread M12x1.25




Next step - adapter. I make 2 variants of it for different sprockets



Assembling motor, install a mount



[youtube]g_s1IUHcISg[/youtube]

and last step - install kit on a bike



[youtube]BcK9duNRfP0[/youtube]

Now I make Typhoon kits and parts for sale. You can order it here.
 
One of tests shows top limit of torque/phase current for this motor.
Controller: Kelly KBS72101X, phase current is max, 110A.

This phase current was very high and motor crumpled gears


I reduced phase current to 85% and now all is ok, battery current 65A, max power 4.5kW.
But my battery was not good and has drop voltage >10v on current 70A.
When I will test with LiFePO4 A123 ANR26650m1b battery, I guess to see over 5kW.
 
Some pics of a kits and a motor with mount






and a laboratory stand :)

[youtube]_ipVHUf8DpA[/youtube]
 
Hey this is really nice.

You will find that Bafang do not make any more BPM II in the next few months, but BPM 1 continues, and it pretty much the same...
 
Samd said:
You will find that Bafang do not make any more BPM II in the next few months, but BPM 1 continues, and it pretty much the same...
Click to expand...
I didn't know it :( BMP1 has different back cover construction.
So bmsbattery.com has BPMII in stock now.

Now I have a plan to make "Typhoon mini" kit with XOFO mini hub in next a couple of monthes.
 
Hi mate,
Nice job ,you could use bmx half link chain between the cranks and the motor shaft as it is stronger and easier to get the correct length without using the tensioner jockey wheel you have.
Darren
 
cheekybloke said:
you could use bmx half link chain between the cranks and the motor shaft as it is stronger and easier to get the correct length without using the tensioner jockey wheel you have.
Click to expand...
sure, can use a single speed chain, but using the tensioner is necessarily because the motor mount has fixed size.
 
evb said:
cheekybloke said:
you could use bmx half link chain between the cranks and the motor shaft as it is stronger and easier to get the correct length without using the tensioner jockey wheel you have.
Click to expand...
sure, can use a single speed chain, but using the tensioner is necessarily because the motor mount has fixed size.
Click to expand...
Thats why i suggested half link chain as you can remove 1 link at a time, plus it can be run tighter than a normal chain due to its construction.
Darren
 
cheekybloke said:
Thats why i suggested half link chain as you can remove 1 link at a time, plus it can be run tighter than a normal chain due to its construction.
Click to expand...
I didn't know about this type of chain before :) Thanks.
 
Very nice mid-mount conversion.
looking forward to seeing your next project with the XoFo.
 
Four monthes have passed and I have some news about Typhoon kit. We found better motor for convertation. It's Xofo XF-V.
This motor is similar to Bafang BPMI but has some important differences:
- new shaft is more easy to manufacture.
- motor is cheaper than Bafang.
- back cover has smooth surface on both sides, there's way to work more easy and accuracy with it.

Also we made some changes in conversion.

Some pics of new Typhoon version



 
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