My wattmetter only shows the voltage

[oigoi]

Firstly I would remove the motor from the scooter and see if the motor itself is tight to turn when it is not attached to the scooter. This will identify if the tightness is in the motor or on another part, for example the bearing for the wheels.

 

[cwah]

I completely removed the motor from the wheel:
[video=youtube;d9Yw9ho4HFo]http://www.youtube.com/watch?v=d9Yw9ho4HFo[/video]

It's definitely the motor that's making this sound. But there is no screw I can use around to completely check what is inside.

Don't know what to do. Is it broken?

 

[oigoi]

OK cwah what happens if you old the motor body (the black part) and try turning the sprocket (the 10 tooth cog on the end). Does the sprocket turn around easily? When the motor is running all of the outisde of the motor should stay still and only the sprocket and the shaft it is fitted onto should turn. They should turn easily if the motor's bearings are good.

 

[cwah]

No, it doesn't turn easily. Like a huge drag.

Do you know if there is something I can do?

 

[oigoi]

think the bearing that has seized is in the end of the motor that is the end without the sprocket and shaft on it. I can talk you through how to dismantle the motor and replace the bearing but it might be tricky to put together again!

If you want to dismantle the motor the first thing you do is remove the sprocket from the shaft. Then I would look for any screws or bolts on the outside of the motor and remove them as they may be holding it together. If there are now screws or bolts the motor will be pressed together and you will need to lever it apart using a screwdriver or similar to lever it apart in the joins on the motor casing

 

[Deleted member 4366]

I's guess that that plate with 4 holes in it at the oposite end to the sprocket unscrews so that you can slide off the outer case. You need a special tool to turn it. You might be able to make one by taking a flat piece of steel, drill a couple od small holes the right size for a couple of nails. If you can make the nails a tight fit and then cut the ends off to leave a short stub after banging them in, it should work. The steel needs to be at least 2.5mm thick and the nails need to be the right size to fit in the holes in that plate.

Hopefully, it's only a bearing, but it could be a bent shaft. It didn't take a whack while you were riding it did it? If it did, forget the above - you'll need a new motor.

 

[cwah]

Oigoi, I'm not sure I can remove the sprocket and shaft because the screw is quite damaged:

When I turn my screwdriver on it, it just shape a larger gap on the metal.


D8veh, I would need to buy a drill then. And also a piece of metal and some additional screws?

It didn't take any whack, it was perfectly fine and suddently I had this problem. Just didn't understand how that happened. I initially thought something went inside the motor.

Fixing that seem complicated

 

[oigoi]

I agree cwah it is a shame but I think that to fix your motor will require more tools than you have, so I think your best option is to buy a new motor. how much will a new motor cost?

 

[cwah]

A new motor would cost around £60 and I'll have to wait 3 weeks before it arrives from Hobbyking:
TGY AerodriveXp SK Series 63-74 170Kv / 3250W

But the part on the top of the motor (with the damaged screw) has been customized, so I'll have to move it to the new motor (I don't know how)


I was actually planning to buy a new drill anyway (it may be useful for my later projects and to put my battery in my bike backpack). Is that what I should buy to fix the motor?
- 350W drill
- What should I get to drill holes and put screws?
- The metal sheet
- The tool to cut the metal sheet

Not completely sure it's the right tools, but as I may need that later, why not get them now?

 

[oigoi]

Blimey cwah that is a fairly powerful motor! Is that correct it says the power rating is 3250w?!

The drill you have shown is a good one I have one like that. You don't have to use a pillar drill you could just use a handheld electric drill:

NEW 500W 240V ELECTRIC POWER TOOL HAMMER DRILL 3 YR WAR | eBay

The metal bar you need something stronger - like this:

Mild steel flat bar 30mm x 10mm x 1metre | eBay

Then you need some bolts that are the correct size to screw into the holes in the end of the motor. Then you could try the method dv8eh has suggested and unscrew the motor end casing.

You can buy metal bar at B&Q it may cost less as there would not be the postage. The bar does not need to be as long as 1 metre, about 400mm long would be plenty.

To drill out the damaged screw you will need some good drill bits. For a job like this I use cobalt ones:

2 x 3.0MM COBALT DRILL BITS 3MM DRILLS TOP QUALITY | eBay

You would probably have to drill the screw out to about 4 or 5 mm depending on it's diameter. Then if the thread in the sprocket is damaged you would have to repair the thread with a tap:

HSS Tap Set M6 x 1 6mm | eBay

 

[cwah]

Thanks Oigi for all these links.

I'm going to buy the drill. I've found the size of the screws:

3.87 mm size. I suppose I would need 4mm drill bit?

I've seen holes on the left and right:

Not sure if it's of any use.

And found un-used metal bar in my flat, maybe I can use them?

Aaaahh.. I feel so newbie.. That's really nice from you helping me.

ps: Yes, modelism motors are so much more powerful than bike motors. But this motor can only handle 3000W during a very short time (and not continuously) because it's for plane.

 

[Scottyf]

Blimey cwah that is a fairly powerful motor! Is that correct it says the power rating is 3250w?!

It maybe drawing that much power for short periods but it has spinvery very quickly in order to create its power. Its like a small engine where the higher the rpm the better.

It will also be quite a loud motor unlike hubs due to the high rpm.

But still its a hungry little beast!

 

[Deleted member 4366]

That hole in the side has a grub screw in it, which you take out with the right size allen key. Maybe you don't have to unscrew that plate on the end. It might just come apart after removing the grubscrew/s.

 

[Deleted member 4366]

This one looks very similar to yours and seems to show the grubscrew screwed out. Maybe the procedure is: unscrew grubscrew and slide off endcap with main outer; remove sprocket; remove circlip; slide off other end cap. It's possible that you'll have access to everything once you've removed the first endcap with the body, so you don't need to take the sprocket off, so don't drill just yet.

Endless-sphere.com • View topic - another 80-100 rear drive build thread (now with pics)

 

[oigoi]

I agree with dv8eh the link he's posted shows one of these motors dismantled so perhaps looking at that will help you understand how it is held together

 

[cwah]

Thanks guys. For now I'm just on the first step: unscrew the top part:

I know there is loctite on it making it impossible to remove without heat. I tried to put my soldering iron on it during few minutes (at 450 C). Then let it cold and try to remove it again.

But it really seem to be stuck. Do you know any other way to remove these screws?

 

[Deleted member 4366]

You don't need to touch that. Start with the other end of the motor by removing the screw that's down the hole.

 

[cwah]

I've seen in other pictures in endlessphere that they may remove the inside from the top side:

Endless-sphere.com • View topic - Stinky Turnigy 80-100 -Nuvinci semi auto

Now I'm not sure anymore from which side I should open it. I was thinking I may need to remove it from the top side?

 

[Deleted member 4366]

I believe that you can normally do it either end, but you can't get the sprocket off, so work from the opposite end. The shaft is separate to the end caps.

 

[cwah]

I removed the screw from 1 side, but from the other side it seems that I can't remove it:

There is no grip for my screwdriver. Or maybe there is nothing to remove?