How to refurbish old motor.

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Mr. Sander
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Joined: Monday, December 3, 2007 - 12:02
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How to refurbish old motor.

Hello V..

My first post to this forum, however I have been a regular visitor for long time but never joined until today. About three years ago I was biking home after work, suddely some guy passed me with his old military bike and I now this type of bike it is withot any gears and hevy as h..., after catch up at the stop light I could have a better look at the his unit - suprice it was electrical, some kind of homebuilt. However this gentleman planted one idee, this ideea has grown stronger every year and I want try to make my own e-bike.

Nevertheless, I always bike all year round, It dosent matter if it snowing, storm, raining 7" nails, or minus 35 Deg. I love to bike exept when it is crap-wheather.

The first problem is limited funds, two kids one car one house etc etc, so for the moment spending money on "what my wife should say unnessesary things" is not high on the priority list. My idee is to design my bike (fun to plan fun to build). Another problem has been to find a suitabel motor without any money, I have searched for an engine during the last year, and suddenly I em very happy owner of a second hand engine... He he, cant stop the grin on my face....

The Bosch GPA 24 part no 0 130 302 013, this motor was used in a permamobile, "very used" see pricture, the motor has built in fan for cooling but the mounting of the engine was in a open area so all road dust etc was sucked into the engine, it is extremly dirty.

No1. I have heard that if you remove the rotor you will destroy some of the magnetic field, the engine will run faster with lower torque. is this true on this kind of motor or is the statament just! I have not yet removed the rotor.

No2. Even if above statement is tru I em forced to totaly disasemble the engine, there is lots of debris/dust/inside. what is the best way of cleaning and what shall I think about during this.

No3. Is there something else that I should be aware of when I cleaning / assemble the engine. Tips wanted.

No4. What shall I do with the brushes?

No5. I have in my possesion nice Hakwer SLA batteries, they are normal 12 volt. what is the best way to charge a battery, paralell as I have read somewher or in my case I have one 24 volt charger, in series but how do you know that the cell voltage is within limit, the batteries can have different internal resistance and then you will overcharge one battery, or?

Sorry long post and spelling as a drunk duck.
Regards,
Mikael

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LinkOfHyrule
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Last seen: 9 years 10 months ago
Joined: Wednesday, October 17, 2007 - 14:54
Points: 730
Re: How to refurbish old motor.

Yah. That's a pretty dirty motor. Definitely needs help. Anyway:

"No1. I have heard that if you remove the rotor you will destroy some of the magnetic field, the engine will run faster with lower torque. is this true on this kind of motor or is the statament just! I have not yet removed the rotor."

1. I don't know where you heard that. You have to remove it from time to time, to clean it out. I think this is only a problem with certain stepper motors. But I don't know. Anyone who does here? You are right about a lesser magnetic field increasing RPM, however, it shouldn't be a problem in your case.

"No2. Even if above statement is tru I em forced to totaly disasemble the engine, there is lots of debris/dust/inside. what is the best way of cleaning and what shall I think about during this."

2. Really I have no idea. I've always kept mine clean. I could go out on a limb and say you could use a toothbrush or something. Compressed air might help a little.

"No3. Is there something else that I should be aware of when I cleaning / assemble the engine. Tips wanted."

3. Don't pinch yourself. Seriously. Those magnets don't fool around. Check the bearings and make sure they're still good. Be careful when you put it back together. If you rotate the brushes (in relation to where they were), you will change the timing. This means that it will only be okay to run it one way. If the brushes end up timed too far ahead, then even the no load current will fry it.

"No4. What shall I do with the brushes?"

4. Well, check them to see if they're still good. Make sure they aren't too worn. If they are, you'll have to get new ones.

"No5. I have in my possesion nice Hakwer SLA batteries, they are normal 12 volt. what is the best way to charge a battery, paralell as I have read somewher or in my case I have one 24 volt charger, in series but how do you know that the cell voltage is within limit, the batteries can have different internal resistance and then you will overcharge one battery, or?"

5. The general consensus here is that it is best to charge the batteries individually. This ensures that the battery gets its ideal charge. You're exactly right about bank charging. The batteries can become unbalanced and some will overcharge, and others won't fully charge. Charging them individually will keep the batteries healthy, and a healthy battery lasts longer.

Good luck!

P.S.: If you're concerned about your spelling, get the Google toolbar. I just discovered it has a spell check button :)!

The author of this post isn't responsible for any injury, disability or dismemberment, death, financial loss, illness, addiction, hereditary disease, or any other undesirable consequence or general misfortune resulting from use of the "information" contai

Mr. Sander
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Last seen: 9 years 2 months ago
Joined: Monday, December 3, 2007 - 12:02
Points: 5
Update refurbish old motor.

CHEAP GEARBOX

One step forward and two step back.
Motor: now cleaned out and works well, appling 24 VDC and just holding the motor feels dangerous, the motor is very strong, my biggest problem is the brush holder inside the motor. Made of soft plastic and not properly fixed in the motor originaly, the cables out from the motor is stiff, just by twisting the cables changes the rpm. I have secured the wires for the moment in the best possible position, this part defenately needs to be upgraded later.

Gearbox issue: my planetary gearbox is beyond save, I have fiddled around and tried to fix the box but now I give up. Spur Gears, attached dwg is made of standard components, have anybody tried this before? I think I will make a try,. / Regards

Bosch_Gear_1.jpg

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