On 24/10/2014 22:31, just fixed it wrote:
On Wednesday, April 22, 2009 3:17:37 PM UTC-5, wrote:
Anyone know how these old singer foot pedals work? There's not much
to this thing, but I can't for the life of me figure out how it's
supposed to work!
The one I have contains a long ceramic tube filled with a stack or
maybe 100 graphite disks. One end connects to the sewing machine
motor (I assume), and at the other end there's a contact that's
brought closer to and eventually touching the contact on the end of
the tube as the foot pedal is depressed.
The foot pedal was dropped and I'm trying to repair it, but so far I
can't get any variable speed out of it - I get either off (when the
contact isn't touching the end of the graphite-disc-tube) or ON-HIGH
when the contact touches the end of the graphite-disc-tube.
Sorry for the miserable description - it's been about a month since I
had the thing apart - just figured I'd post here to see if anyone had
any suggestions.
thanks!
-Pete
Just fixed one of these and found this ancient thread. Thought I might put this up for people finding this thread. The carbon discs get burned, so go through the stack and discard any that have broken, then take a very fine sand paper (600 grit)and lightly sand both faces of each disc. Make up the space for any discards or accidentally broken while sanding discs with some small washers. It is important that the gap be filled with something strudy, not foil or steel wool. We don't want springinees to the stack. The discs are poor conductors and need to pushed very hard together to decrease the resistance, therefore increasing the motor speed. You don't want the little metal nub at the end of the tube that engages the arm to be mobile. Do not bend the leaf spring unless you think it has been changed, it's tension is set to not break the discs. Good luck.
Good on you.
I went to an open day with these people
http://www.tfsr.org/
they have a room , with expert retirees , repairing hand and powered
sewing machines as well as all the carpentry and engineering tool
repair/reconditioning