alanjohnturner
Jedi Trainee
Offline
This motor has a 130 degree gear-wheel and came from a TR3A most likely.
4/4A use 120 degree gear-wheels but evertyhing else is the same.
You can swap the gears about to make any such motor sweep any angle from 100 to 150 degrees.
Often these come up for sale minus the gear. The gears seem indestructible and so can usually be reused.
It ran OK, but took more current than they should do, indicating it was a bit stiff.
It always amazes me how well these have stood up and I've yet to see one that is beyond repair.
But there are a couple of common failures and so here I dismantle this and show how to restore and improve these.
It came looking like this:
https://www.flickr.co...04/12569961143/
https://www.flickr.co...04/12569960223/
There is a bit more corrosion underneath than usual but this is insignificant.
Four screws hold the top-plate, one missing but I've got new ones.
Slip off the Horseshoe clip and C-clip, don't loose the tiny thin shim from the crank-pin.
The bronze conatct is for the self-parker.
https://www.flickr.co...04/12569957713/
This is a carbon-brush set, in good order, note the orientation of the "grooves".
https://www.flickr.co...04/12569956373/
The 130 degree gear, arm and cone-washer
https://www.flickr.co...04/12570304214/
https://www.flickr.co...04/12570301184/
Store the armature carefully to prevent breaking any wires.
If the carbon brushes wear down the two arms will cut grooves into the copper.
I can "skim" these but this one is good. The black ring is normal.
https://www.flickr.co...04/12570297144/
This shows one of the common problems
https://www.flickr.co...04/12569945753/
The arm is bent up. Happens if you try to remove connection to the wire-rack without releasing the Horseshoe-clip.
The arm will scrape on the cover and the wire-rack won't go smoothly into its tube.
You can do without this extra friction.
It takes a few wiggles to get the big self-taps out of the pole-piece.
Go easy they could break off and this would be awkward to fix.
https://www.flickr.co...04/12569923693/
After 1 hour in Caustic-soda. Wear protection!
https://www.flickr.co...04/12593543515/
https://www.flickr.co...04/12593984004/
4/4A use 120 degree gear-wheels but evertyhing else is the same.
You can swap the gears about to make any such motor sweep any angle from 100 to 150 degrees.
Often these come up for sale minus the gear. The gears seem indestructible and so can usually be reused.
It ran OK, but took more current than they should do, indicating it was a bit stiff.
It always amazes me how well these have stood up and I've yet to see one that is beyond repair.
But there are a couple of common failures and so here I dismantle this and show how to restore and improve these.
It came looking like this:
https://www.flickr.co...04/12569961143/
https://www.flickr.co...04/12569960223/
There is a bit more corrosion underneath than usual but this is insignificant.
Four screws hold the top-plate, one missing but I've got new ones.
Slip off the Horseshoe clip and C-clip, don't loose the tiny thin shim from the crank-pin.
The bronze conatct is for the self-parker.
https://www.flickr.co...04/12569957713/
This is a carbon-brush set, in good order, note the orientation of the "grooves".
https://www.flickr.co...04/12569956373/
The 130 degree gear, arm and cone-washer
https://www.flickr.co...04/12570304214/
https://www.flickr.co...04/12570301184/
Store the armature carefully to prevent breaking any wires.
If the carbon brushes wear down the two arms will cut grooves into the copper.
I can "skim" these but this one is good. The black ring is normal.
https://www.flickr.co...04/12570297144/
This shows one of the common problems
https://www.flickr.co...04/12569945753/
The arm is bent up. Happens if you try to remove connection to the wire-rack without releasing the Horseshoe-clip.
The arm will scrape on the cover and the wire-rack won't go smoothly into its tube.
You can do without this extra friction.
It takes a few wiggles to get the big self-taps out of the pole-piece.
Go easy they could break off and this would be awkward to fix.
https://www.flickr.co...04/12569923693/
After 1 hour in Caustic-soda. Wear protection!
https://www.flickr.co...04/12593543515/
https://www.flickr.co...04/12593984004/