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Open a q128c

Posted: May 15 2017 12:38am
by RyanC
It looks like I damaged the wires coming out of my q128c. I'm trying to figure out how to open it to replace them, luckily I bought the extra cable kit....

Are there screws under the rotor? I put a little locktite on those and 2 of them are going to be difficult to get off. I took off the 3 on the spline side and the jam nut etc.

I can get the stripped Allen bolts out of need be, but hoping I don't have to unlace the whole wheel...

Thanks

Re: Open a q128c

Posted: May 15 2017 6:46am
by motomech
I assume they are like the Q100's.
To remove the three pan-head screws. you need a hand-held impact driver w/the correct-sized bit. They are not expensive. The trick to using them is to preload the tool before striking it w/the hammer. That is, twist it til the bit is firmly in the screw slots.
There are some tricks to get the cover turning to un-screw, but since you have a used rear motor, I can tell you right now, you will have to make/have made a special tool, something like the one at the bottom of this page;

https://endless-sphere.com/forums/viewt ... e&start=25

The reason you need the tool is because when you pedal, the force of the cassette tightens the motor side-cover.

Re: Open a q128c

Posted: May 18 2017 6:12pm
by RyanC
Yeah-

Yikes this thing is really on there...what a terrible design. My wife's bike has a bafang motor and one of hall sensor solder joints came loose. Easy fix.

This thing might just be trash at this point. I tried several different pin wrenches, like the adjustable types that work for grinders etc. I don't have enough machining skills or tools to make up a tool like in that other thread. I guess I might try to make something like that out of plywood and use some screws or something to get into the holes and see if that works as a last ditch effort.

What a shame. I really liked this motor, I was even planning to pick up some more of them for some other bikes. It's crazy that they don't at least sell the tool at BMS. I did email them...

Re: Open a q128c

Posted: May 18 2017 6:17pm
by Ykick
Problem with these type rear motors is that pedaling seriously tightens the housing cover. Maybe try some heat from a propane torch? Don't get too carried away but a little heat/expansion might release enough to get it off with your tool.

Re: Open a q128c

Posted: May 19 2017 5:27am
by motomech
RyanC wrote:Yeah-

Yikes this thing is really on there...what a terrible design. My wife's bike has a bafang motor and one of hall sensor solder joints came loose. Easy fix.

This thing might just be trash at this point. I tried several different pin wrenches, like the adjustable types that work for grinders etc. I don't have enough machining skills or tools to make up a tool like in that other thread. I guess I might try to make something like that out of plywood and use some screws or something to get into the holes and see if that works as a last ditch effort.

What a shame. I really liked this motor, I was even planning to pick up some more of them for some other bikes. It's crazy that they don't at least sell the tool at BMS. I did email them...
What do you want for a $100 motor that YOU damaged?? Maybe BMS Battery should send a tech over to fix it.
First off, the special wrench doesn't have have to be all shinny and polished like the one in the link I provided. Any shop w/ a gas welding out-fit, a grinder and a drill press could make a wrench out of a flat piece of steel. Instead of welding of pins in, bolts could be used. If you looked around, somebody probably could make it for $25 or less.
I told you I knew some tricks and although I'm not sure you even want to fix the motor, I'll give you one.
Take a piece of 3/4" plywood about 2 ft. square and drill 3 holes aligned w/ the recesses in the motor cover. Then install bolts using 2 nuts and 2 flat washers per bolt, "double nutting" the bolt to secure it. Then, standing one the plywood, fit the cover recesses on the bolts and turn the whole wheel..

Re: Open a q128c

Posted: May 19 2017 4:40pm
by RyanC
motomech wrote: I told you I knew some tricks and although I'm not sure you even want to fix the motor, I'll give you one.
Take a piece of 3/4" plywood about 2 ft. square and drill 3 holes aligned w/ the recesses in the motor cover. Then install bolts using 2 nuts and 2 flat washers per bolt, "double nutting" the bolt to secure it. Then, standing one the plywood, fit the cover recesses on the bolts and turn the whole wheel..

There we go! I'm going to try this. Apologies I was just frustrated- it seems like needing access to the inside of these motors is inevitable...plus I miss my bike!

In any case I'm going to give this a shot.

Re: Open a q128c

Posted: May 20 2017 5:06am
by d8veh
Q128s are quite easyto open without special tools. Same technique as a q100.

Undo one of the 3 countersunk screws in the sise-plate
Screw in a cap-head screw with a washer under its head.
Draw a pencil line across the join where the side-plate screw thread joins the hub near the spoke flange.
Use a hot air gun to heat up the hub until it's just about too hot to touch
Whack the screw head with a large hammer and drift so that it turns the side-plate in an anti-lockwise direction,
Check the pencil line to see progress. It needso go about an inch befireyou can unscrew the rest by hand.
If the screw gets damaged, get a new one and move to the next of three holes.

It's probably a futile effort. It's very difficult to thread the wire through and rejoin them. I've done it a couple of times, but you need a lot of patience and care. The motors are so cheap, it's probably easier to get a replacement. You don't need to rebuild the wheel or buy the complete wheel. When you unscrew the side, the whole motor core comes out with it, so you just swap cores. Practice getting the side-plate offyour old motor, then use your technique on the new one, which will be much easier because the thread won't be so tight. You probably won't even need heat on it.

Re: Open a q128c

Posted: May 20 2017 7:32am
by RyanC
d8veh wrote:Q128s are quite easyto open without special tools. Same technique as a q100.

Undo one of the 3 countersunk screws in the sise-plate

Ah so the countersunk pan head screws don't have to come out? I was wondering because you can see the core inside turn with the axle anyway...thanks this technique seems the easiest yet. Do you know off hand is it a M5?

I might as well give it a shot at least. Thanks-

Re: Open a q128c

Posted: May 21 2017 3:50am
by d8veh
The screws fix the clutch to the side-plate. Here's the clutch separated on the left. If you leave one or more screws in, it remains fixed to the side-plate like the second photo:

Image

Image

Re: Open a q128c

Posted: May 21 2017 4:13pm
by ntr
This is my tool. It takes quite some force to open, this one was just strong enough (I din't heat up the hub). You might even want to use som heavier steel.
DSC03337.JPG
DSC03337.JPG (142.14 KiB) Viewed 1445 times

Re: Open a q128c

Posted: May 21 2017 4:45pm
by zukster
I made a simple tool with a piece of plywood and a brake disc rotor.

https://endless-sphere.com/forums/viewt ... =2&t=86991

since your hub is still is the wheel you can simply clamp the cap that unscrews in a vice really hard, the turn the wheel counter-clockwise.

I don't think I could have opened some without a vice.

Re: Open a q128c

Posted: May 21 2017 5:13pm
by 999zip999
D8veh good advise and pics. Thank you.

Re: Open a q128c

Posted: May 22 2017 2:17pm
by molybdenum
This is great information everyone! I will need to open up my Q series motors soon, and this will help immensely.

Re: Open a q128c

Posted: May 25 2017 3:41pm
by RyanC
zukster wrote:since your hub is still is the wheel you can simply clamp the cap that unscrews in a vice really hard, the turn the wheel counter-clockwise.
Bingo-

My bench vise didn't open that big, but I went to a auto mechanic and they got it open easy-peasy. I went ahead and ordered a large bench vise for the future.

Unfortunately it seems that the problem with my motor is something other than the wires coming out of the axle. They were a little frayed, so I figured that was it, but I taped them all up, and checked out the solder to the PCB and everything looked good but it still gets an 06_Info error. I tried the same setup with my front motor (q100h) and it works, so it must be something else. I ordered another so when it get's here I'm going to swap the core and dig a little deeper.

Re: Open a q128c

Posted: May 25 2017 4:49pm
by zukster
RyanC wrote:I went to a auto mechanic and they got it open easy-peasy.
I did the exact same thing for my first motor, then I got a big vice for the next one.

What device is giving the 06_Info error? There are a number of tests that you can try here:

http://www.ebikes.ca/learn/troubleshooting.html

Re: Open a q128c

Posted: May 26 2017 8:18am
by RyanC
zukster wrote:
RyanC wrote:I went to a auto mechanic and they got it open easy-peasy.
I did the exact same thing for my first motor, then I got a big vice for the next one.

What device is giving the 06_Info error? There are a number of tests that you can try here:

http://www.ebikes.ca/learn/troubleshooting.html
The Slcd-6 with a S12S controller. I know everything with the controller and display are fine because they drive the q100h without errors.

That looks like a good troubleshooting guide though, once I get the replacement Q128C I'll definitely go through that