Foredom parts??

So this box managed to walk out the side door of the jewelry shop. But the metal foot pedal has an issue. Anyone sitting on any parts for these? I think I need the 2 switches and the plunger to make this work again. Or just buy the plastic version if it will work with this. I'd rather get this heavy pedal working again if possible.
Any of this help? https://www.foredom.net/product-cat.../flexible-shaft-machines/speed-control-parts/






The two switches in here look a little funky and I'm not sure what that blue thing should look like. I'm guessing plunger that spins and contacts the switches...

 

Those two switches are a VERY common type of switch, they're used in countless other things, I used to have a bunch of them that I scavenged from and copier. You should have no trouble at all finding replacements, any place that sells electronic repair parts should be able to point you in the right direction. Google "cherry microswitch" and you'll see lots of similar switches, they come in 3 or 4 different sizes, get one with the same dimensions as yours and you should be golden.

 

Cherry switches.... Good to know! Thanks! Any idea whats going on with this blue thing?
I think the switch is an E61

 

E61 is obsolete. Got replaced by https://www.digikey.com/product-detail/en/DB1C-A1AA/CH288-ND/280834/?itemSeq=332290880

Now to figure out that blue thing. Are they spring loaded to spinny spin around?

Looks like this had something to do with this..


Interesting... The patent explains how this thing works. That bent piece of shit was twisted and as the pedal gets pushed it twists or screws itself into the blue thingy thus changing the speed by actuating the switches. Learn something new everyday.
https://patents.google.com/patent/US4322711

 

The blue thing is probably a solenoid to alternate forward and reverse functions between the two different contactors or high-speed and low-speed.

Edit; a better look at it, it looks like a mechanical speed control for two speeds. It looks like it switches it from "off" to a 4 pole to 2 pole. This equates to off, low speed, high speed, Depending on foot position.

 

I stuck the VOM on the pot and it's F'd. No part numbers on it either... only CTS. Between that and the twisty piece of metal, this thing might be terminal. I cannot find a thing any where about this SCR-1 foot control. According to the net, it's never existed. Storyline of my life!

I guess I need to ask foredom tomorrow what pedal will work with this motor and just shut up and color.

 

The blue thing looks like a potentiometer or "trimpot" to me based on the construction of it, does it have three wires into the circuit board?. You should be able to rotate through 270 degrees or 3/4 of a turn with a small blade screwdriver in the center slot under all that grease.




The spiral metal strip would convert linear motion into rotation as it runs through the center hole. I use linear potentiometers as a more reliable replacement with an adjustable bellcrank to get the right amount of travel.

 

Yes, there are three contacts.. but notice the blue disc is egg shaped to operate the switches correctly.

 

There are mechanical ways around that cam operating the switches, I'm guessing that bent strip of metal is normally twisted into a spiral and threaded through a hole in the circuit board and then through the screwdriver slot in the middle of the cam to make the cam on the trimpot rotate?.... I see from rereading your post about the patent that it does that. About all you can do is panel beat that strip back into position and replace the busted microswitch. A linear potentiometer would be the ideal fix but may not fit and you'd have to still operate the microswitches with something. The circuit in the patent is pretty much identical to a TRIAC based lightbulb dimmer circuit so it would be possible to substitute one of those into a foot pedal control. There were some plastic footpedal boxes on Ebay a while back that used a moulded rack and pinion to rotate a potentiometer that would have been ideal.

 

That blue thing looks like a pot with a custom cam lobe top. The pedal rotates it to control the speed but at full depress it trigger a switch. looks like at full stop it also triggers a switch. This is probably due to current draw through the SCR at full press. That's a common enough type of pot. You should be able to find a replacement and just swap out the top. I have seen them new in years past but I can't remember (if i ever knew it) the brand name.

 

What plug does the foredom take? I'm sitting on two foredom pedals I can't use because I bought the wrong type for my machine and then accidentally bought a second one somehow...

They are the plastic type they sell though.

 

The crumpled ribbon of metal was originally given a helical twist. Stepping on the pedal drove the helix through the slot in the center of the potentionmeter, rotating the pot and changing the speed.

 

Spelter is correct, that helix thing spins the pot one way and the other. My new switches came in today, so I'll try to tear into it later tonight. Maybe I can get a number off the pot.

 

When you get tired of messing with that one get a foot pedal for a sewing machine, $20.