Graupner 600 smokes

Hi all,

I bougt a brand new Graupner speed 600 engine today. I mounted it on my test-bank and it runs just fine. But at the moment it stops, smoke comes out of the engine (just a little bit), and the axle is verry hot (the bit on the back side of the engine). I burn my finger when I push it agant the axle.

Is it just some oil from the bearings, or is it something else and should i return it to the store? (the store is closed now.. otherwise I would have called them).

Sven

Reply to
Sven Goosen
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What are you loading it with? Try a drop of oil on the rear bearing and the front as well.

The brushes will need bedding in, but it shouldn't get THAT hot on the normal prop - 8x5 or 7x6 - not enough to burn you, tho the case will get too hot to touch after a few minutes.

Reply to
The Natural Philosopher

Sven Goosen wrote: : Hi all,

: I bougt a brand new Graupner speed 600 engine today. : I mounted it on my test-bank and it runs just fine. : But at the moment it stops, smoke comes out of the engine (just a little

Carbon dust? If your motor is new, the brushes are probably setting and wearing to the proper shape. I have broken in a few Speed motors under water, and it tend to get quite murky from the carbon in the process...

-Tapio-

Reply to
tapio.linkosalo

Hmm.. that could be... I'll run it again tomorrow and see if it's smoke or dust (if i can tell the diff.)

What do you mean with braking it in under water? I can't imagine you put the entire engine in the water? (I don't think the electrics can stand water too well..)

But I'll give the guy a call tomorrow, and see what he thinks about it.

Sven

Reply to
Sven Goosen

Put the motor in a glass of water, hook up a battery of about 1/2 the voltage you're going to use, and let it run for a few minutes. You'll see the water get murky in about 10 minutes from the carbon brushes wearing to the shape of the comutator. It doesn't hurt the motor, it just breaks in in quicker. Just let it dry out, then lubricate the bushings or bearings with a drop of light machine oil.

It could be the smoke you see after running was caused by the brushes arcing, which is why you break it in under water. The arcing pits the brushes, reducing the area in contact with the comutator and thus the efficiency of the motor. However, this still doesn't explain why it gets hot enough to burn you. I would be suspicious of that motor.

Morris

Reply to
Morris Lee

Ahh, I could be wrong but I bet you need to properly 'break' it in. It sound dodgy but this has worked for me in the past. Put your wires to the motor and sink it in water with NO prop. Run it ONE charge of your batteries and the brushes should seat with no extra problems. Then use some light oil for the bearings.

Reply to
Six_O'Clock_High

Wow... This is something i would never have expected from a Electric motor.. (water and electrics usually don't mix well)

Does it have to be half the voltage? or can it be the normal voltage? (My batt. pack is sealed.. so it's verry hard to use only 3 cells) And there are several electrical components on the engine (to prevent electrical interference I think) can those resist water? And how about rust (oxidation) that's not a problem at all?

Thanks allot for the verry good tip.. it's something i would never had thought of doing (let alone dared to put a engine like this in a bowl of water!)

And the guy at the RC store told me that i could use the engine with no problems of the shelf... Guess he wants me to come back and spend more money :-)

Sven

Reply to
Sven Goosen

Reply to
Paul McIntosh

Sven,

You're not gonna want to to hear this, but if you've already run that motor with OR without a load, using the full power of a 7.2V battery pack, you have probably already caused arcing and pitting of the commutator and brushes.

If so, the brushes will NEVER seat/make contact as they would have, had you properly broken in the motor. The motor will NEVER develop the power & rpm it could have.

Sad but true facts...

Bill

Reply to
Bill Fulmer

Urban myth.

Facts.

|(i) Motors come without bedded in brushes.

(ii) they get better after a few minutes running.

(iii) its better not to put TOO much curent through them before the brushes bed in as there ins't that much bursh area to carry the curent, and you can get a little pitting of teh commutator, however unless you are running a massively ppwerfl motor at massicve current, this all polsihes off.

(iv) doing thie running in underwater helps both wash the carbon out, and keep the brushes cool, but is inno way mandatory.

(v) All you are doing, like any new mechanical engine, is polishing up rubbing surfaces to make a good snug fit.

To this end, a few minutes running at hopefully less than full power will do the job. Water helps get the dust out thats all, but it generally blows out by itself.

Yu can see when you look at teh brushes that the acrs and sparkling starts out along the brush edges. Once it moves to be almost anywhere around teh brush surface, the brushes are bedded in.

this is going to boil off first run.In addition, if the motor HAS got any oil, or any other kind of loose muck in or near the windings - which get pretty hot - often 100C or so - Not to worry.

The faileure modes of these motors are simple.

(i) The brushes wear out or break. That takes a LOT of high speed running.

(ii) The windings get so hot the insulation melts, and then tehy short. That takes a seriously overloaded motor. Usyually teh controller blows up first.

(iii) The magents get too howt and lose magnetism. Thats a clasc dign of a motor run too hot too long. They draw more current, and may seem to be more powerful before they burn out compleletly.

(iv) The bearings run dry and run out - leading to shaft chatter and loss of power.

(v) The shaft or case gets bent in a crash, leading to a stiff motor that draws lots of current - and may burn out.

Seriously pitted commutators are very rare except in high performance motors that are seriously abused. The 600 is not such a motor :-)

Reply to
The Natural Philosopher

There is a good site somewhere that explains under water breakin. Can't find it though. Use a glass of water with a drop of dish soap in it. Run on 3 volts. (two 1.5 volt d size cells). Run it in reverse for 3-4 minutes then run it in the direction you will use it for 3-4 minutes. When done, shake all of the water out of it and oil the bearings.

John VB

Reply to
jjvb

That is an electric MOTOR!

Engines are GAS/GLOW/Diesel Engines!

Learn the difference, Goose.

D> >> What do you mean with braking it in under water? I can't imagine you

Reply to
Checkursix

"Checkursix" schreef in bericht news:rQl2c.47180$ snipped-for-privacy@fe2.texas.rr.com...

sorry mate.. where i come from there is no diff.. it's just a translation error..

take it easy.. no need to shout..

Learn to read.. it's Goosen

unless it's a diesel ;-)

Reply to
Sven Goosen

Excellent article about electric motor break-ins in the latest Backyard Flyer including water break-in, half voltage break-in, etc.

Reply to
Fubar of The HillPeople

| To this end, a few minutes running at hopefully less than full power | will do the job. Water helps get the dust out thats all, but it | generally blows out by itself.

Right. I think the water thing started with car racers who were given a brand new cheap can motor for their race (to make things fair, I guess), and they wanted to get it broken in quickly, because they only had a few minutes to prepare it for the race.

Still, a few minutes of slow running seems prudent before really giving it full throttle. But if you can't find two 1.5 v cells to power it -- no worries. You can just power it with your plane's power system -- just keep the throttle down. In fact, you can break in the motor in your plane if you wish -- just remove the prop (for safety more than anything else) and put it on a low throttle setting (just enough to let it spin slowly) and let it go for 10 minutes. Then charge your battery up again, and go fly!

Reply to
Doug McLaren

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