Waterlogged Bafang SWXH

[mgfx]

Hi all,

My first post on here is a plea for help! I have recently caught the ebike "bug" after buying a Raleigh Dover panasonic crank drive bike for my wife and trying it myself. Fantastic machine!

I bought myself a much used and filthy dirty Torq 2 a couple of months ago (spent all the money on the Raleigh!) and have restored it to an almost new condition with invaluable assistance from Fleccs Torq site, this forum and Cyclezee. I am very pleased with it, completely different from the Raleigh, but a very good bike.

In my new capacity of "expert" (I dont think!!! )I have now been asked to help out a friend who has inherited a 15 month old Claude Butler Glide 2, which has a 36v Bafang SWXB front hub motor, complete with hall sensors. After the demise of the original owner, the bike was left half in /half out of a shed for months, and although the handlebar module /controller lit up, and the battery is fine, the bike would not run.

It is essentially a pedelec with 6 levels of assist provided by the throttle, but has a "launch control" mode to 4 mph, so the motor can be run without the need to turn the pedal when testing. When I tried to operate this, the motor would make a soft "click" and then nothing. Testing the motor phase wires showed a rise to 10.6 volts, then drop back to 5volts on one of the wires when I operated the throttle.

I tested all the wiring for continuity, and tested all the usual suspects (brake cut outs,etc) for problems, but all seems well.

I decided to take the motor apart, which I believe has got to the root cause of the problem. The unit leaked brown water from the axle when I took the wheel off, and there was plenty more inside when I separated the motor from the casing. The SWXB unit has six screws holding the side panel, so no special tools required as such, just a bit of gentle persuasion. The gears and housing were in a sorry state, but I cleaned everything up, freed off the gears, re greased and reassembled the unit. Launch control tried again, and the motor turned, very slowly at first then slightly jerkily, nowhere near the right speed but at least turning.

So if I am right in distilling down all the collective wisdom on this site, the likely problem is the Hall sensors have burned out or become water damaged. I am more than happy to have a go at replacing them ( and have traced the sagas of a couple of members who have done the same thing) but I am now stuck on a mechanical rather than electrical point.

Does anyone know how the side plate, which is spinning freely in its bearing, is fixed on the axle? And how it is removed? I dont want to force it unneccesarily as its only a piece of aluminium, but without removing it I cannot get to the sensors.

I know that it could maybe got up and running using a sensorless controller, but the current controller is linked to the handlebar module which is a combined battery meter, assist level control, launch control, and cycle computer all in one, so we would like to be able to keep all those functions if possible.

I just need to get the side cover off the axle for starters!

Any help most gratefully received.
Mark

 

[wurly]

I think hall sensors are more likely to 'burn out' if the axle should ever twist and damage the insulation of the wire. That was the case with one of my hubs, where i decided to replace the hall sensors. I might add i didn't have to, my controller works in either sensored or sensorless.

Do you know if your controller works in sensorless mode? why not first disconnect the halls sensor plug and try it again? to replace the hall sensors is quite a bit of work.

 

[shemozzle999]

Hi Mark,

Do you mean SWXB in the thread title?

I have just purchased a new one of these motors (SWXB).

I think it is just pressed on the shaft.

Screw the 2 hub nuts onto the shaft on the cover plate side and lock them together but dont have the shaft protruding through the top nut.

Find an old paint tin to fit slightly inside the cover plate diameter and deep enough to clear the bottom of the motor assembly.

Place the motor in the tin, then with a block of wood placed over the nut for protection tap it lightly with a mallet until you get it to move.

If it remains tight apply some penetrating oil and leave overnight then re-try in the morning.


If you needs spare parts contact Jane at:

http://www.aliexpress.com/store/group/easy-broken-parts/612941_211853776.html

 

[mgfx]

Thanks Wurly,

No it only operates in sensor mode unfortunately. I have read that water is one of the enemies of the sensors?

 

[mgfx]

Yes, SWXB of course, rubbish typing!

I was thinking of trying that sort of approach, but dont want to do any damage! The wires come through the axle on this side, so will only have the one nut to work with (without disconnecting all 8 wires in the connector). I got the motor separated by a simliar method using a sharp tap on the other side of the axle to drive the innards out. If that didn't work I was going to try and get hold of a 3 leg gear puller but it came apart OK. The side cover is fairly free spinning, and I thought it was probably a press fit, but dont like hitting things without confirmation! Thanks for the advice.

Hi Mark,

Do you mean SWXB in the thread title?

I have just purchased a new one of these motors (SWXB).

I think it is just pressed on the shaft.

Screw the 2 hub nuts onto the shaft on the cover plate side and lock them together but dont have the shaft protruding through the top nut.

Find an old paint tin to fit slightly inside the cover plate diameter and deep enough to clear the bottom of the motor assembly.

Place the motor in the tin, then with a block of wood placed over the nut for protection tap it lightly with a mallet until you get it to move.

If it remains tight apply some penetrating oil and leave overnight then re-try in the morning.


If you needs spare parts contact Jane at:

easy broken parts - Shop Cheap easy broken parts from China easy broken parts Suppliers at MW motor on Aliexpress.com

 

[shemozzle999]

If it transpires that you cable is damaged, I have a replacement cable available for hall sensored motors which has a weatherproof plug/socket connector small enough to slide the nuts and washers over.

 

[mgfx]

Thanks Shemozzle, I really appreciate the offer. I am hoping that the problem is water damage (eg the Hall sensors have blown due to being wet when powered up), as apparantly the bike was working fine until the death of its owner. The front wheel was exposed to three months of summer rain, so its either repair it or get a new motor. Hopefully I can replace the sensors, but if its anything else we will have to look at a new motor. Where did you get yours from? The majority I see for sale in the UK are sensorless versions. Going to try to get the side cover off the axle later today, will keep you informed!!

 

[shemozzle999]

I purchased mine from here but only because I needed a high speed version for a Brompton conversion, there are other suppliers of this motor for your wheel size:

Aliexpress.com : Buy 16,18,20,22,24,26,28 inch electric bike BLDC front wheel motor QMWB from Reliable front wheel motor suppliers on MW motor

You would have to contact Jane first with your requirements i.e. Wheel size 700c, hall sensored, voltage etc.

They do sell parts for this motor so you might be able to get just the replacement stator complete with hall sensors, but again be very specific about what your motor requirements are.

It should come with the standard Bafang connector but I would get it confirmed before ordering.

Jane is very accommodating, but please try to keep your emails polite, short and to the point to avoid confusion, should you need to use them. I find attaching photos highlighting the problem areas help a lot with the communications.

Unfortunately they have had to change their couriers so delivery charges have increased slightly.

 

[mgfx]

Well Shemozzle, you were right, the cover is pressed on, and I managed to remove it by placing the plate over a 4" underground soil pipe connecter,( a perfect fit and very strong) and tapping firmly. The water damage is worse than I thought. The end of the bearing the plate pushes on to has a rim of rust, the circlip holding the drum onto the axle had rusted through, and the stator plate does not want to come out of the drum at present, so I have soaked the shaft with penetrating oil and will try again later today. I have a feeling I will have to go down the replacement motor route, unless I can clean everything up like new. If I do that, I think I will separate the new motor, and fit it into existing casing which is undamaged and still laced into the wheel. Thanks again for your help

 

[shemozzle999]

Hi Mark,

Well done.

Sounds as if you have got a plan.

If you have access to a camera your photos could be of help to other members.

Regards, shemozzle999

 

[mgfx]

Hi Shemozzle,
Some days are better than others! Got the stator plate out with liberal amounts of penetrating fluid, and cleaned out all the rust. As luck would have it I had ordered a brushless motor/controller tester from China, arrived this morning. So I reassembled everything, took some photos, put the wheel back on, and all I got was a slight stutter. Then nothing. Worse than before!

I hooked up the Tester, to test the windings, and either the tester is not working, or the windings are shot! Sods Law applies to the connectors on the tester, the plugs and sockets for Hall wires are different to those in my wiring harness!

Watched a Utube clip on testing Halls with a multimeter last night, so tried that. Two sensors stay at 5.0v as the wheel is turned slowly, the other has no voltage.

Operating the "lauch control" sends 10.6v down one of the power phase wires, turning the wheel makes no change to this.

So reluctanly I have come to the conclusion that this motor has had it. I think that the Halls must have shorted out when power was applied after the motor became waterlogged. There is no form of sealant around the cable entry through the axle, I think water must have tracked down the cable and into the heart of the motor.

So unless anyone has a SWXB complete with halls for sale in the UK, I will try your Chinese source for a replacement unit.

When that arrives, and the bike is working, I will have a go at stripping this one again and replacing the halls, but need to check that the rest of it is able to work once I get my head round this Chinese Tester!

Thanks again for everything. Will post photos when I work out how!

 

[shemozzle999]

It is a shame about the timing.
I have just ordered a couple of high speed SWXU motors and they are including a replacement motor shell for the SWXB that was damaged in transit.
If I had know about your problem earlier I could have asked for a complete motor and sent you the unwanted complete stator assembly.

 

[Deleted member 4366]

I hooked up the Tester, to test the windings, and either the tester is not working, or the windings are shot!

Just in case you don't know, you have to spin the motor backwards to test the windings with those testers. The motor then works as a generator and lights the LEDs in the tester.

And you have to rotate the motor backwards to test the hall sensors.

 

[neptune]

Testing motor windings with a mutimeter is very easy. Put the multimeter on Ohms. If there are several ohms ranges, select the lowest one. Connect the leads of the meter together, and it will read close to zero ohms. You have 3 phase wires, call them A,B, and C. Put one meter probe on A and one on B. You should get a reading of less than 1 Ohm . Now test between B and C . Finally test between C and A. The 3 readings should be identical or very close. Now put the meter on the highest Ohms range, or just on "Ohms" if there is only one range. Put one probe on any phase wire, and the other probe on the metal "stampings" on which the coils are wound, or if the motor is assembled, on the hub shell. The reading should be exactly the same as if the meter probes are connected to nothing. For this test, you must not touch the metal part of the probes with your fingers. If the stator passes all these tests, the coils are OK. Windings seldom give trouble. Post your test results.

 

[Old_Dave]

Also.. I don't think the hall sensors are anything special and suitable replacements should be available in the UK, rather than suffering the slings and arrows of the China or HK postal systems


Sent from my iPhone using Tapatalk

 

[shemozzle999]

Hi Mark,

To post photos:

After you press the Reply to Thead button the text box opens, press the Go Advanced button, located under the text box, it will open up additional options under the text box.
Scroll down to the Manage Attachments button - when pressed a new box will open called the File Upload Manager - go to the Add Files button and it will open another box - press the Select File button and it will open your My Computer folder.
Go to the folder that contains your files and left click the file you want (tip! to select more than one file hold down the ctrl key and it will keep adding files or if the files are in a group left click the top file and while holding down the shift key left click the bottom file all the file in the group will be selected) when you have selected all the files you want press the Open button on the My Computer folder box.
It will transfer the file names into the Select box opened previously now press the Upload Files button.
Your files are transfered to the File Upload Manager left click and hold and drag the photos you want displayed into the lower Attachments box.
Finally press the Insert Inline button and your photo information will be added into the text box.

I suggest it might be easier for you to print this guide out rather than try to follow it on screen.

 

[mgfx]

Thanks d8veh,

No I didn't know that. I was following the instructions that came with it, which say "turn the motor clockwise, along the normal advance direction" for both "winding of the motor" and "Hall of the Motor" tests. May well be an incorrect insruction, I will try this in reverse tomorrow!.

Thanks for the tip
Mark

Just in case you don't know, you have to spin the motor backwards to test the windings with those testers. The motor then works as a generator and lights the LEDs in the tester.

And you have to rotate the motor backwards to test the hall sensors.

 

[mgfx]

Thanks Neptune, I will try this tomorrow, and put the results up on here.

The motor was badly waterlogged when powered up again, but I did think the windings would have survived. IF this proves to be the case, I will have a go at the Hall sensors!

Testing motor windings with a mutimeter is very easy. Put the multimeter on Ohms. If there are several ohms ranges, select the lowest one. Connect the leads of the meter together, and it will read close to zero ohms. You have 3 phase wires, call them A,B, and C. Put one meter probe on A and one on B. You should get a reading of less than 1 Ohm . Now test between B and C . Finally test between C and A. The 3 readings should be identical or very close. Now put the meter on the highest Ohms range, or just on "Ohms" if there is only one range. Put one probe on any phase wire, and the other probe on the metal "stampings" on which the coils are wound, or if the motor is assembled, on the hub shell. The reading should be exactly the same as if the meter probes are connected to nothing. For this test, you must not touch the metal part of the probes with your fingers. If the stator passes all these tests, the coils are OK. Windings seldom give trouble. Post your test results.

 

[mgfx]

Thanks Dave,
I hope so too!
Following another thread on here on replacing sensors, I got some SS41s as replacements from Conrad Electronics.

If all else checks out OKJ as per D8veh and Nepyunes suggestions, I will have a go a replacing them!

Also.. I don't think the hall sensors are anything special and suitable replacements should be available in the UK, rather than suffering the slings and arrows of the China or HK postal systems


Sent from my iPhone using Tapatalk

 

[mgfx]

Sorry for the crap typing! should read OK and Neptune!