Cracking open a BaFang8Fun ? How?

[SoSauty]

I need to get a metal gear into my little BaFang. I'm running 48V and am nervous that the nylong plastic gears could go soon (1,000 miles now). There's no seam in the cover opposite the power wire/cassette gears. Underneath the gears, the cover has a seam, and three 3/8" dimple holes. The seam appears to be very precisely fit, maybe painted over, and almost invisible. I've conjured up a tool with 3 5/16" bolts to fit in the dimple holes, yet can't break the cover loose. Seems I saw a thread on how to do this in the past, but struck out after looking for more than an hour. Please help I'd love to have reliable transportation come Monday

 

[dnmun]

i forgot where that thread is too, maybe ask zukster. but the cover threads on and you use a pin spanner in those holes to unscrew it after taking off the freewheel. never done it myself, but you could mount some bolts in a piece of plywood that match the holes and then screw that to your workbench and push the hub motor down on it and twist it off in spite of the locktite, or find a pin spanner that fits. not the sorta tools most people have. maybe the yahoo ad spam bot in the banners at the bottom of the page will come up with a source for PIN SPANNER when it reads this.

wow, where is yahoo when you need them? wow, when did that happen?

go google then if you wanna find the pin spanner that would go around the freewheel threads and will fit the hole. it only has to fit into one hole to function as a spanner.

 

[SoSauty]

dnmun; thanks! I made a spanner wrench, sortof, but your comments about placing the bolts thru a plywood or work table got me to thinking. So I put the board/homemade spanner on a short bench,braced its' handle against the wall, got my wife to help hold the wheel down, and I turned the wheel (rather than the spanner handle). Almost gave up, but 1 last heave hoo and it broke loose :wink: I'm on my way to having the metal gear installed and ready to ride!
http://i76.photobucket.com/albums/j25/SoSauty/BaFangOpenCover-1.jpg
Thanks dnmun

 

[dnmun]

neat, i was thinking you could just screw the wood piece to the bench and then twist by grabbing the rim while pushing down against the bench to set the pins in the hole.
to mount the bolts on the plywood, you could even use the type of nut that has the three little tabs that dig into the wood for wood furniture construction. whatever they are called.

neat work, certainly beats the $40 channel-lock pliers someone used before.

ps: put that picture on your avatar for people to see.

 

[johnrobholmes]

I have used channel locks in the past when all else fails. I have one motor here that wouldn't come open no matter what I tried. Even 3 feet lever arms wouldn't budge it.

 

[Lyen]

That is very clever of you. I will try to do the same. Thanks!

 

[GrayKard]

you could even use the type of nut that has the three little tabs that dig into the wood for wood furniture construction. whatever they are called.

They are called: t-nuts

Gary

 

[dnmun]

hey, yeh, i knew that,,, just on the tip of my tongue. they really work well too.

you should measure the radius of the holes so people are able to make their own jig. use a hole saw for the freewheel opening in some plywood and some t-nuts every 120 degrees. what size screw? 3/16"?

screw plywood jig to workbench or stump, add wife to hold it down, presto torqo, opened

 

[Russell]

I don't have a close-up of the Bafang QSWXB but this is the side you take off, after removing the 6 screws of course. The seam between the right side cover and the housing on this polished Bafang QSWXB is almost invisible but it is there. I used an Xacto knife to score the joint followed by a chisel and hammer to crack it open. After I got it opened a pinch I went around the motor with a flat-blade screwdriver to widen the opening until I could grab the cover and wiggle it off.



The second motor, a GM MIni which is actually a Bafang QSWXH, was much easier to open using the same technique. Here is a picture of that motor with the seam clearly visible.


View attachment 1

-R