capstan sandblaster

[Mars Amp Repair]

Hi folks,
Well I managed to find a turntable stand on forum (thanx again Enzo ;-] )...now I'm in search of another ancient test fixture.

Set the Wayback machine to circa 1975:

Does anyone remember the device we used to use for sandblasting 8 track capstans? It was a thin vertical standing white plastic gadget that was all molded plastic. On one end it had a quick fit for the compressed air & then it had a hole through from side to side with sealing grommets.

You'd fill it with the sand they used to use to clean spark plugs & then you'd stick the capstan through the grommets & blast the capstan & voila...new surface.

I'll have to find some of the consumer audio sites & post this there, too. I have an old WEM echo unit that needs the capstan resurfaced. We also used to use PC etching solution to etch the shiny surface to a dull finish, but that method never lasted all that long.

Thanx, glen

[jrfrond]

Forget about the Rube Goldberg device. When I need to resurface capstans, I let them run and wrap a piece of #400 wet/dry carbide sandpaper around it and run it up and down to get an approximate crosshatch pattern, then I'll clean it off with lacquer thinner. Works great. Been doing this for over 20 years.

[drewl]

never even heard of it.
Anyway, I used a light fine sandpaper to buff and smooth the corroded flywheel shaft of an echoplex I recently rebuilt.

[Enzo]

I'm with John, I would do the exact same thing.

Seems like an overly complex gadget for such a thing.

Of course if you want it for show and tell, that's different.

[unparalleled]

Hi folks,
Well I managed to find a turntable stand on forum (thanx again Enzo ;-] )...now I'm in search of another ancient test fixture.

Set the Wayback machine to circa 1975:

Does anyone remember the device we used to use for sandblasting 8 track capstans? It was a thin vertical standing white plastic gadget that was all molded plastic. On one end it had a quick fit for the compressed air & then it had a hole through from side to side with sealing grommets.

You'd fill it with the sand they used to use to clean spark plugs & then you'd stick the capstan through the grommets & blast the capstan & voila...new surface.

I'll have to find some of the consumer audio sites & post this there, too. I have an old WEM echo unit that needs the capstan resurfaced. We also used to use PC etching solution to etch the shiny surface to a dull finish, but that method never lasted all that long.

Thanx, glen

I serviced hundreds of tape machines over the decades, just hold sandpaper flat to face of capstan while it is revolving in play mode until a clean surface is seen, then hold sandpaper to pinch roller while revolving until fresh rubber is exposed. A bit of meths on a cotton bud will shift any remaining rubber residue.

[Mars Amp Repair]

thanx all,
The device was actually a manufactured fixture made expressly for this purpose. Not Rube goldberg at all. It produced a like-original professional sandblasted surface on the capstan that was consistent & wouldn't mar the tape.

Also many of the capstans on the 8 tracks rode on an upper & lower bushing which required that you keep those surfaces untouched.

Anyway, it worked really well esp when we were doing quite a large quantity back then. I'd still acquire one if I could find one for the nice professional results & longevity of the resurfacing. I guess ya had to be there...

At this point I'll probably defer to the old tried & true wet sandpaper or crocus cloth methods. thanx, glen