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Old Jan 10, 2010, 07:38 AM
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London, UK
Joined Aug 2005
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Astro 05 brushed motor seizes, sizzles & frys

Running an Astro 05 with a 3.3 Astro Superbox
Max trottle drawing 17 amps as shown on wattmeter
Ran it for more than 5 min
I could see a small spark inside the motor every 2 or 3 min but did not think this was a problem
After 7 min of running it suddenly seized, there was a bit of smoke.
When I opened the motor the main spindle where the brushes make contact with the spindle this part had been totally chewed up. One of the black "ears" appeared to have its glue melted and had move position causing the carbon brushes to eat into the spindle. This motor had seized on a previous bench test at a lower throttle but I thought I had fixed the problem by regluing the ears. I am glad this happened on the bench rather than in the air.

Diagnoses - black ear glue mechanical failure
Result - one 05 Astro destroyed

I continue to be a fan of Astro brushed. But this was frustrating.
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Old Jan 10, 2010, 07:56 AM
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Long Valley, NJ, USA
Joined Dec 2001
1,721 Posts
Sorry for the loss of the motor. The failure seems unusual; however in all fairness a five-minute bench run may have allowed the system to heat up too much.

There's probably a high temp epoxy that works best for the brush holders.
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Old Jan 10, 2010, 06:01 PM
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East Anglia, UK
Joined Sep 2002
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Don't give up hope. I have full sets of spares. What is needed to get it back up?

Amature, fully wound? Casing? Brushes? Endbell?
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Old Jan 11, 2010, 05:35 AM
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London, UK
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I believe the part where the carbon bushing makes contact with the spinning shaft have been wrenched out from the shaft along with one of the black ears along with the part of the front golden housing. The only thing left intact is the black casing, the Astro superbox (3.69:1) including the 13T helical pinion, which was undamaged.

I have a replacement motor (never flown Astro 15 cobalt challenger) in my parts bin and will be using this after replacing the stock 2:1 gearbox with my 3.69 SuperBox. However what I need is to borrow a gear puller that will remove the existing factory fitted pinion from the Astro 15. The shaft size is 5/32 inch. The pinion is very tight though. I have tried with a standard GWS after heating the pinion with a blow torch and it still will not budge... the GWS puller jaws broke in the attempt!!

If there is anyone who can lend me / recommend a strong gear puller; or will pull this pinion gear out themselves (at my risk) please let me know. I am also in the process of contacting Kurt at New Creations in Texas to see if he has any ideas for a tight pinion gear.
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Old Jan 11, 2010, 05:58 AM
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East Anglia, UK
Joined Sep 2002
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Fairly sure I simply put a small spanner under the pinion and tapped one off with a drift..no that was the BIG gear, not the pinion..

I must have replaced a pinion tho. Hmm.

15 is an 05 with low KV armature. Needs 4s to wake up, really.
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Old Jan 11, 2010, 09:22 AM
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Quote:
Originally Posted by vintage1 View Post

15 is an 05 with low KV armature. Needs 4s to wake up, really.
Thanks for pointing that out... I am "long" 3s, so i would be better of fixing or finding another Astro 05. You'll meet me in the classifieds.
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Old Jan 17, 2010, 03:26 PM
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Cripes, that commutator had exploded..

you have mail..its repaired..
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