received new used 646se with a pair of batteries inside

[Burgerman]

A totally destroyed brush, and a new (almost) brush...

Which do yours look like?
These ruined/destroyed ones like on the left, came from my 2 year old chair.
When I hit it with the compressed air and spun the motor a huge cloud of black dust came out.
The oe on the right was its replacement, new. After a month.

Not all brushes look the same. Some are shorter even when new. The only way to actually KNOW is to compare your old ones to the MANUFACTURERS brand new ones for that motor specifically. By then you already have them! So fit anyway.

[yeshelp]

HI
ok I have been able to remove the stuck brush with a bit more insistance and back and forth movement. It was compressed powder around the brush that was creating a layer of material creating a blockage.

I plan to brush the holes and brushes with a End-Tuft Soft Tapered Trim Toothbrush parondontal toothbrush. Ai says that The bristles (filaments) themselves are made of a synthetic material like nylon or polybutylene terephthalate so that seem ok.


To look at the Armature, you write Yes turn the motor. Look with a light/torch. Look at all of it to make sure no damage.
When unpluged and on freewheel the axle does not want to turn nor the armature i tried to push a bit with a screwdriver. Probably since the brakes are automatically on when unpluged. So I guess your suggestions is to leave the 4 holes open and plug the motor back in the power module to look by he hole window? That armature probably turns fast when the joystick is pushed. I might only be able to look at random spots instead of checking all the armature if it turns too fast but I can try to see what I can see.

About the black dust. Opening the can would be better but the pozi 1 2 3 dont really fit deep in the front cap screws of the motor. There is probably rust layer preventing to go deep in the bottom. It feels like i would strip them if I try them like that. Also the motor probably has a seal or glue (maybe dried) that would probably not be as water proof after if I open it. The motor works so Im not sure it is a good idea to open it .

What i understand from your suggestion is to just leave the 4 holes open and blow air east west north south a coulple of times while the motor is plugged in and moving from the joystick .Is that what you meant or did you mean to blow air in the holes unpluged while turning the motor in my hands manually like literally turning the motor on itself ?

Idont know if the black powder would be air pushed on other parts inside the motor instead of coming out from the holes ... Could it bring new problems or is it still a better choice than doing nothing about it ?

When you say take a while, just to have an idea, would it be blowing air for 2 min 5 min 10 minutes ? Since the motor will be pluged in but in my hands should I try to position the holes lower(motor vertically ) so that at least gravity brings the powder in this part? I dont know if there are separations in the motor but if it kind of open space blowing while the motor is vertical (hole at the bottom)could make sense.

thanks
here are pict of the front screws

[Burgerman]

So I guess your suggestions is to leave the 4 holes open and plug the motor back in the power module to look by he hole window? That armature probably turns fast when the joystick is pushed. I might only be able to look at random spots instead of checking all the armature if it turns too fast but I can try to see what I can see.

The armature will not turn at all if you removed the brushes! And the power module will also give an error.
You can either REMOVE the brake (and give that a clean while you are at it) and that will allow you to turn the wheel/motor. Or you can take a 12V battery and ower JUST the brake.

About the black dust. Opening the can would be better but the pozi 1 2 3 dont really fit deep in the front cap screws of the motor. There is probably rust layer preventing to go deep in the bottom. It feels like i would strip them if I try them like that. Also the motor probably has a seal or glue (maybe dried) that would probably not be as water proof after if I open it. The motor works so Im not sure it is a good idea to open it .

The back dust is the rest of the brushes after they wore away. Its carbon. Its abrasive, ruins bearings, and wears laquer off windings, and causes sparking and errosion of commutator. So you need to remove it. You only need compressed air. Remove the two screws, use the CORRECT brand new screwdriver which willlikely be a posidrive no 2 probably, and hit it sharply in place with a hammer so it shocks the bolt/screw and seats the X on the head correctly. Keep tapping as you try to unscrew it. DO NOT let it slip as you will destroy its head if it slips just once. This requires experience...

What i understand from your suggestion is to just leave the 4 holes open and blow air east west north south a coulple of times while the motor is plugged in and moving from the joystick .Is that what you meant or did you mean to blow air in the holes unpluged while turning the motor in my hands manually like literally turning the motor on itself ?

Physically by turning a wheel.

Idont know if the black powder would be air pushed on other parts inside the motor instead of coming out from the holes ... Could it bring new problems or is it still a better choice than doing nothing about it ?

When that motor is running it is whipped up into a cloud of abrasive dust by the airflow... Get rid of as much as you can.

When you say take a while, just to have an idea, would it be blowing air for 2 min 5 min 10 minutes ? Since the motor will be pluged in but in my hands should I try to position the holes lower(motor vertically ) so that at least gravity brings the powder in this part? I dont know if there are separations in the motor but if it kind of open space blowing while the motor is vertical (hole at the bottom)could make sense.

As long as the air pressure is HIGH and lots of airflow and that you PHYSICALLY turn the motor into a few different positions you just keep going till no more dust comes out. Unless you completely disassemble the motor and clean with degreaser, brush, and at this point you will need new bearings, etc and its all way too much for you.

thanks
here are pict of the front screws

Take them out and remove the brake, clean brake, turn motors by hand while blasting air in all 4 holes.
The black dust is carbon dust. The dust is actually the brush material.

[shirley_hkg]

When unpluged and on freewheel the axle does not want to turn nor the armature i tried to push a bit with a screwdriver.

Yes. You are right about the brake in ON when there were no power.

However, it is released, when you turn the freewheel lever to PUSH.

It doesn't want to turn because it is in low gear (armature turns much faster than axle).

Have to turn the axle HARD. Put the nut back and turn with a wrench.

Clean the carbon dust by an air gun, or a can of compressed air.

[Burgerman]

turn nor the armature i tried to push a bit with a screwdriver.

I cannot stress enough that you NEVER do that!!!
Any tiny scratches or bigger marks that you cause on that soft copper commutator will destroy the brushes and cause terrible damage. If you inadvertently damage any of the copper windings, the segments of the commutator, or the point that those windings connect then the whole motor core is now junk! Dead. And even if it still works will soon die.

DO NOT put anything like that into those holes!


I keep telling you that you need experience. This is the wrong thing to gain that experience on. You stand a bigger chance of ending up with worse motors than you started with. Theres only2 sensible ways to fix this.
1. Leave well alone. Save for new ones.
2. Total strip and recondition. Which isnt really possible as parts are not available which means replacement unless you are very experienced and can make, adapt other parts and understand what you are doing. And even then some important parts are still not available. Whilst fitting new brushes may be possible the rest of the motors will still be worn too. They all wear out as a unit and lose efficiency.

[yeshelp]

Have to turn the axle HARD. Put the nut back and turn with a wrench.

Hi Shirley,
Thanks for the trick

[yeshelp]

. DO NOT let it slip as you will destroy its head if it slips just once. This requires experience...
Thanks for the answers Burgerman.

I will try to get someone to hold the motor while I try to hammer the screw on using pozi attached to the breaker bar.
If I just try to turn and hammer I guess it could slip since between hammering times there is no pressure on the bit correct? What is the best way to hammer it while turning so that it does not slip? would push turning with the breaker bar plus hammering be it?

The guy happens to be a electro mecanician for trains but never touched a wheelchair. he might have some usefull tools to bring if I ask him to. He told me that in wort case scenario if we strip the screw, it is posible to take it out and retread the hole. Humm sure I would like to avoir that but is it realistic since the hole of the screw of the front cap is so small? Would the metal allow retreading?

He told me we could use brake cleaner to clean the motor. Is this ok to use on the parts?If not I will not allow him to use it.

He might have the envy to open the motor can . To know the consequence of that, I would like to know something. Atm the motor is waterproof I imagine. Do you guys know if the motor can is metal on metal with the gearbox side or is there something in between to make it waterproof. If there is I would order some of that stuff before since we would probably try to do what is to be done in one shot.

--------------
The third screw is behind the freewheel lever. I removed the bolt at the very end of the motor as seen on picture. The freewheellever metal part used with our fingers is a bit loose but does not come out .. Im am not sure if I have to try to force it out OR if I need to do something else.Maybe it is normal that I cant take it out.
By something else I mean that there is a yellow screw inside the hole from the part I just removed and I also see that there is an hexagonal shape to the thing that contain the screw in the very center....

Here is a 30 sec video of it https://vimeo.com/1141708468?fl=ip&fe=ec
thanks

[Burgerman]

Where to start...

Get a few old motors, lawn mowers etc and strip them. Learn what works, how things go togther, learn how and why, learn from and gain experience and all of the above will become obvious and trivial. I genuinely dont know how to explain to anyone in a painting by numbers way how to do this stuff. Just take it apart! Cant believe we are still looking at this same motor!

You are going to need to learn. You will damage things and may fail. But theres only one way that motor comes apart and thats to grab your tools and just do it.
Why ARE you taking it apart? I already explained that parts are not available and that you will be unlikely to know how to evaluate what you see anyway. And are quite likely to do more harm than good. If you want experience practice on things that are vaueless that dont matter when you screw them up. Theres really no aternative.

Personally I would have took it off the chair and fully striped it in about 30 mins.
At that point I would evaluate what I saw, and either ordered parts, and properly cleaned and painted the rest while bearings, cush drive, brushes, seals etc arrived. Then reassembled, tested, fitted. Or I would have ordered replacement motors and thrown the old ones away.
In another maybe 2 additional hours.

What are you aiming to do and why? Just taking off a couple of parts isnt going to achieve anything.

[yeshelp]

Hi
Well the suggestion is to blow air into the 4 holes while turning the motor wheel. To turn the motor wheel and armature the brake needs to be powered or removed and to do that the cap need to be removed. To remove the cap there are at least the 3 tiny screws to be removed. One of them is behind the freewheel level (either freewheel or drive position still dont provide acces to it). So I try to remove the freewheel lever.

Could I just blow air through the 4 holes without rotating the wheel -armature? maybe idont know . The suggestions was to have the armature turn both to see it surface and to turn it while I blow the air. That is what I am trying to do.

Since the person I talked to said he would use brakecleaner to rub the parts of the motor I was wondering if it is a good practice too or if it should not be done. The other questions seem usefull to know to maximise the chance I dont strip it and to know if the motor would still be waterproof after I open it if the guy is enthousiatic about opening it while he is there.

[martin007]

Simply apply pressurized air to the brush holders.

[Burgerman]

What do you mean by strip it? The thread? The X in the head? If you do as I suggested it would all have been removed days ago,

Blowing air in without turning it? Will half clean the dust out... Whats the point.

Why not just power the brake and turn the motor? Or use the freewheel lever? Or whatever it needs/takes?
Brake cleaner? Where will you use that?? Its carbon tetra chloride. It shouldnt hurt anything. But firing it into an assembled motor is pointless. Stop looking for cans of stuff to fix everything!

The time it took to write that last post was all the time it takes to actually do it. I cant believe we are still talking about a couple of screws! Just undo them.

[yeshelp]

Yes by tripping I meant the x of the 3 tiny screws. I only have sometime times in the evening to work on the chairs so yes it can look a bit slow but I also had to let the penetrant work.

I think I will not open the brakes in the end and just blow air through the 4 brush holes.

When I was trying to remove the freewheel lever I tried what I could meaning that I loosened the central screw(the one yellowish not the removed on that seems just a protection) inside the hole on the picture. It was not oubvious that it was progessing out even though it was turning. Now I know it is probalbly not realistic to ask how much do I have to turn it. The other motor screw at the same place I checked was still wanting to turn(clockwise) when screewing which leads me to think maybe it is not a holding tight type of screw system but an adjustment kind of bolt .

So for the motor I turned it to unscrew, I just very approximated turned the same amount of turns which could change adjustement if it is the role of this screw.
So my question is anyone knows the role of that screw in the very center? so that I can be aware of the changes or problem it could cause if I have screwed it too much or not enough.
thanks

[Burgerman]

Looks like it adjusts the amount of "action" or free play or how much the lever lifts the brake. So if adjusted too far in or out it will not fully release the brake when operated or will hold the brake off even when its in the normal position and the brake wont hold.

Again, its all about experience. How to adjust it? By feel.

If that lever actually works you can turn the motor...

Also. When you do a video or photo, turn your phone horizontal. My laptop or desktop PC doesent work on its edge...

[yeshelp]

Ok thanks ,
Is it a black or white situation that if the freewheel works it means the screw is in between the too much and too little?
or could it be like bicycle brake meaning that the brake could be partly but wheel still turning?


When on drive both motors have the wheel immobile and when on freewheel both whels can turn but i notice the one that I m unsure to have screw it back to same place is a bit harder to turn with my hand.

I guess having a partially engaged brake is what i want to avoid when rolling

When you say to adjust it by feel, do you mean that when I screw tighter or looser this screw I would se a difference in the amout of force needed to turn the wheel by hand?

[Burgerman]

When you say to adjust it by feel, do you mean that when I screw tighter or looser this screw I would se a difference in the amout of force needed to turn the wheel by hand?

Yes. You want it to have:
a) when the brake is in normal driving position to have free play. So that it isnt partly releasing the brake while you roll.
b) that it releases the brake FULLY so that you can easily turn the motor and wheel so its easy to push.

It is adjustable because when manufacturered it had to be configured. And because it can go out of adjustment due to wear and corrosion.

[Burgerman]

When you use the word STRIP that means a thread. Its very unusual to strip a thread when undoing something. Thats usually caused by an ape with a tool. Stripping a thread is very different from damaging or rounding a bolt or screwhead. If those "slip" once they are already damaged. Tool and fastener. Once.

I honestly have never stripped a thread since I was a teenager. I LOOK at the size and pitch of the threads. The length of the area that is threaded. The type of materials, the hardness of the bolts or nuts, or even the type of self tapping screws into plastic. Experience tells me when something is feeling right, or is starting incorrectly. Or that is too tight. I know when to stop or to apply more pressure to prevent a screwdriver slipping. I also know when building engines or pipework, or wheelchairs what is the correct tightness by feel. I know when to use grease, loctite, replacement bolt, which type of washer or no washer. What type of bolt or screw. All of that comes from a lifetime of taking everything I ever had apart. That includes motorcycles, years of engine tuning, working on aircraft and cars. And houshold stuff... Year and years. Thousands of errors! Thousands of mistakes, and thousands of times repairing stuff I cannot reach or see by feel. Brakes, hydraulics, electrical and electronics, and laptops, tools, wheelchairs etc.

You lack ALL of that. What is seemingly obvious and easy and intuitive to me is hard to impossible to you. I watch my carer doing stuff for me today and it frustrates the hell out of me to watch him as he obviously just doesent get the stuff I see as obvious. The way he HOLDS a screwdriver... I can see he will damage the thread, or the head of the screw or the part he is working on LONG before he actually does it. When you try and explain he thinks you are nagging him, but he does not know what he doesent know!

An example.
I never allow a screwdriver or socket or allen key to slip ever. Not EVER. A QUALITY correct type and sized screwdriver such as the Posidrive ones will SNAP a screw off before the tool will slip. Unless its damaged.
If a cross head screwdriver slips JUST ONCE it goes into the box of old junk screwdrivers. Because even if its not obvious by casually looking at it, the carefully ground edges are now rounded and damaged. Once... Before the now damaged screwdriver ruins something else expensive I get rid of it! To my carer, that screwdriver is perfectly "fine" because of his ignorance. So when he allows it to slip (again...) , I just see another £4.99 cost... And whatever new damage it will cause. Theres a 1000 such examples like this in my brain. Because I learned from EXPERIENCE!

[Raro]

When you use the word STRIP that means a thread. Its very unusual to strip a thread when undoing something. Thats usually caused by an ape with a tool. Stripping a thread is very different from damaging or rounding a bolt or screwhead. If those "slip" once they are already damaged. Tool and fastener. Once.

I honestly have never stripped a thread since I was a teenager. I LOOK at the size and pitch of the threads. The length of the area that is threaded. The type of materials, the hardness of the bolts or nuts, or even the type of self tapping screws into plastic. Experience tells me when something is feeling right, or is starting incorrectly. Or that is too tight. I know when to stop or to apply more pressure to prevent a screwdriver slipping. I also know when building engines or pipework, or wheelchairs what is the correct tightness by feel. I know when to use grease, loctite, replacement bolt, which type of washer or no washer. What type of bolt or screw. All of that comes from a lifetime of taking everything I ever had apart. That includes motorcycles, years of engine tuning, working on aircraft and cars. And houshold stuff... Year and years. Thousands of errors! Thousands of mistakes, and thousands of times repairing stuff I cannot reach or see by feel. Brakes, hydraulics, electrical and electronics, and laptops, tools, wheelchairs etc.

You lack ALL of that. What is seemingly obvious and easy and intuitive to me is hard to impossible to you. I watch my carer doing stuff for me today and it frustrates the hell out of me to watch him as he obviously just doesent get the stuff I see as obvious. The way he HOLDS a screwdriver... I can see he will damage the thread, or the head of the screw or the part he is working on LONG before he actually does it. When you try and explain he thinks you are nagging him, but he does not know what he doesent know!

An example.
I never allow a screwdriver or socket or allen key to slip ever. Not EVER. A QUALITY correct type and sized screwdriver such as the Posidrive ones will SNAP a screw off before the tool will slip. Unless its damaged.
If a cross head screwdriver slips JUST ONCE it goes into the box of old junk screwdrivers. Because even if its not obvious by casually looking at it, the carefully ground edges are now rounded and damaged. Once... Before the now damaged screwdriver ruins something else expensive I get rid of it! To my carer, that screwdriver is perfectly "fine" because of his ignorance. So when he allows it to slip (again...) , I just see another £4.99 cost... And whatever new damage it will cause. Theres a 1000 such examples like this in my brain. Because I learned from EXPERIENCE!

It's infuriating, no matter how you explain it to whoever you want to do it seriously, in the end you prefer they don't touch it because you know they're going to mess things up and on top of that they often get angry.

[shirley_hkg]

When on drive both motors have the wheel immobile and when on freewheel both whels can turn but i notice the one that I m unsure to have screw it back to same place is a bit harder to turn with my hand.

Freewheel lever unlocks chair to let you push it around manually.

In driving, brakes are released electrically (solenoid) and always 100% released. It can't be partially. Simply examine this by listening to the "click" , every time you push the joystick and when you stop.

Sometimes, we encounter a completely damaged freewheel linkage. However, we still can drive the chair as long as we get chance to fix it. Can be months later.

You are overly concern. Relax.


The drag issue below can be easily verified. Drive your chair for 15 mins and touch the motors to feel any unusual difference in temperature.

I guess having a partially engaged brake is what i want to avoid when rolling.

[yeshelp]

Ok thanks , good to know it is not possible to have a semi engaged brake.
Will hand touch the motor in road nest time I road test it.

[martin007]

Stop looking for cans of stuff to fix everything!

[yeshelp]

Hi everyone,
I air blowned the 4 holes of the 2 motors until nothing seemed to be released.

Most motor brush holes are rather clean but there is one that even brushing with paper toilet around a round metal chirurgical tool without metal to metal contact(my mini tooth brush was not fitting in) there is some black left in the hole of the brush as we see in the pictures. I wounder if I should clean that with some kind of liquid. Do I need to liquid cleen the dark chalk part of the brush too?

There is also the electric question about the brush. I manipulated the brush kind of brass part with my fingers and humans we have oil on the skin. Oil insulate electricity I think. Is it important to clean the brass part of the brush and its hole or is it such a detail nobody does it? what to clean it with ?

THanks

[Burgerman]

Dont clean the brushes, throw them away.
Get new ones. Theres no point replacing old brushes.

The brass square "holes" all need to be cleaned completely. They are how electricity is transfered. And the brushes must slide smoothly.
Use a small wire brush or something. Should be clean with no oxidation.
https://www.amazon.co.uk/Zocipro-T-Shap ... B0DLND81ZL
These are DESIGNED for the job.

Dont use liquids... Or amazon miracle fixes unless its DeOxit. You wont like the price. Use that only AFTER you clean to the metal.

Then fit the 8 new brushes.

It will/may sound a tiny bit strange until the new brushes bed in properly after a day or so. Once put back together lift the wheels off the ground, then run at max speed for 15 to 30 minutes.

[Burgerman]

Your PHOTOS are now the wrong way around!!!

Also you SHOULD be doing this. Or even fitting new brushes is a full repair.

As I said in the beginning. Repairing motors is a waste of time unless you also replace all bearings, shims, seals, grease, motor couplings, clean properly, brushes and brakes. Just fitting brushes is a waste of time really. Because the rest of the motor wears out too.


youtu.be/oB-h-vZc6FY

[yeshelp]

Hi thanks for the link, the metal brush might not go into corners though, would it be ok to use a fine grit sandpaper instead?



I see Deoxit has many products with different pourcentages. G is for gold, sheild seems for extreme environments and D seems for general purpuse but there are choices
D 100l only 18 doll [url] https://www.amazon.ca/D100L-16BX-DeoxIT ... 305&sr=8-6 [/url]

and D5 spray can at 36 dol [url] https://www.amazon.ca/Caig-Deoxit-Conta ... BV4G&psc=1
[/url]

Are they valid choices? i would just buy one

-------
About the brushes, It would make sens to change them indeed if I can find some compatible at low price like you said.
Are you certain that the jive one are compatible?How did you figure it out they are compatible?
Could you provide the url where you saw the price please I cant find it?

Here is serial Number of the chair frame S64A-052891 .
manufactured 07 2012 .

Here is the sunparts us . I dont find Jive in there. Would compatible brushes be under different name? http://www.sunparts.us/partscatalog/template/index.php

Here is the sunparts canada. Cant find Jive in there neither. [url] http://www.sunparts.ca/partscatalog/template/index.php
[/url]
On eparts.sunrisemedical.eu searching with 112281 I can see a line with jive (as on picture ). but I cant see a price. Also I can add it to the cart but strangly I dont see a cart button nor a purchase pay button!. Maybe that is not the site you are talking about.

Thanks

[ex-Gooserider]

One of the reasons a brush won't come out easily is if it has worn to the point where it is either dropping below the level of the brush holder (unlikely given the state of the others) or gotten 'cocked' over to one side a bit so it's wedging... Short of dismantling the motor to get access to the inside of the holder, the only real way to get a stuck brush out is to do a lot of wiggling and gentle pulling... It can sometimes help to push down w/ a probe at the same time in order to cause the brush to wiggle in different directions until it lines up with the holder enough to come out. (this is a sign that the brush should probably be replaced...)

The other reason is if there is corrosion or other debris partially blocking the upper parts of the holder or wedging between the sides of the brush and the holder. In both cases the best fix is to try to blow out the holder and possibly gently clean the inside of it, wiggling the brush will also help to dislodge debris...

Mostly it's just a case of wiggling it 'just right'...

ex-Gooserider

[Burgerman]

I use deoxit D5 because it works for the last 30 years!

Sunrise do not sell to the public. Go to a shop that is a sunrise dealer...

Wire brush WILL get the corners. You dont want sandpaper as you will end up with abrasive dust in the motor all sealed in!

The REAL way to clean them is to fully strip the motors. Replace bearings, in gearbox, motor, cush drive, brake, repaint, rebuild with new brushes after a REAL CLEAN. As I said theres only one REAL way to fix motors. And unfortunately you just dont know enough, dont have the experience or skills, and will likely do more damage than good.
If I was you I would buy a set of motors, fit them, rebuild the chair as new, fit new batts, tyres, upholstery, bearings, stainless bolts, grease, and throw a sheet over it and call it your backup chair. Put the old motors on a shelf as emergency spares, or ship them to a motor restoration company. Or take your time and fully rebuild. But I dont think you will be able. Remember almost all parts are not available anyway.

[yeshelp]

the only real way to get a stuck brush out is to do a lot of wiggling and gentle pulling... It can sometimes help to push down w/ a probe at the same time in order to cause the brush to wiggle in different directions until it lines up with the holder enough to come out. (this is a sign that the brush should probably be replaced...)

HI Ex Gooserider, Yes wiggling them a lot is what worked. I used a screw driver small to encourage the wiggling.
thanks

[yeshelp]

8mph linix motor as used on the Jive chair, same as yours.
Part 112281 Motor brush kit for 4 - pole motor 4 pcs./pack £ 6.00
So £12 total. Plus delivery. Sunparts website.

Hi
It would be nice if I could get new brushes from sunrise to have piece of mind. when I provide them the serial number of the chair S64A-052891 they say the price is 124 dol so 150 dol for 4 brushes from the shop and that is not even installed. 300 dol plus tax for 8 brushes seems a lot.

If it is easy to find the url of the place where you saw them at 6 euro for 4 that would be nice. I tried but cant find what you found. I could try to ask them to send it to the shop or call the shop so they order them.

How do you know that the ones at 6euro are the same as the one sunrise phone peole talk about using the serial ?
Also why would they be so inexpensive (not even 2 euri each) the difference in price is 25 times fold multiplyer.

Thanks

[martin007]

You look for a trustworthy seller on eBay.

[yeshelp]

You look for a trustworthy seller on eBay.

The thing with ebay it that I would have to know what I am looking for and it seems that it is not only the dimensions to get right but also the grade and or composition and maybe other stuff that I am not aware of . When doing a search with @112281 motor brushes@ and @646se motor brush@ what comes up are very different brushes some of them dont even look like the ones I search .

Unless you had a different startegy when saying to look for a trusworthy seller?
A seller can be trusworthy in the sens that he will send what you buy and have a good feedback about expedition but how to know if the seller actually knows which brushes are needed for the motor? So many people are careless in their work for simple tasks, when we talk about choosing a brush that will not harm the motor, I m not sure they will put effort into checking to make sure It is a correct one.