Part for Unimax thumbwheel decade switch - Page 1
Forum section: electronics / repair

author: jrmymllr
author_rank: Regular Contributor
timestamp: June 06, 2025, 05:07:08 pm
content: Does anyone know where to get the endcaps for these Unimax/C&K thumbwheel switches? The back is stamped "71 C&K" but "Unimax" is printed into the plastic. I haven't found anything. I can find the individual switches, but not the endcaps. Maybe they are unobtainium?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: June 06, 2025, 05:51:24 pm
content: Even the switches themselves seem to be available primarily (maybe only) in the surplus/salvage market.This is the kind of problem that 3D printers are made to solve. You can even customize the end caps to best fit your application/mounting. The printers are now cheap and I find that through making parts for my electronic toys and replacements for various household items they more than pay for themselves. If you are willing to go Chinese JLC3DP will print designs for you.

author: jrmymllr
author_rank: Regular Contributor
timestamp: June 06, 2025, 06:49:37 pm
content: Quote from: CatalinaWOW on June 06, 2025, 05:51:24 pmI don't have have a 3D printer but that is a good idea. The only downside is the shape of it is somewhat complex.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: June 06, 2025, 11:49:39 pm
content: I did a little more looking and you may be able to buy them at Digikey. They have several variants of the C & K switch. Don't know which one you have. If you can find the switch style you have at Digikey, download the data sheet. That has options for the end cap styles and part numbers for them. Then search on the part number. Digikey had the one I looked at for $2.10.The pictured end caps are not that complex. Easily printable with the possible exception of the locating pins. You can work around that with insert pins.

author: jrmymllr
author_rank: Regular Contributor
timestamp: June 09, 2025, 03:30:26 pm
content: Quote from: CatalinaWOW on June 06, 2025, 11:49:39 pmThe endcaps for the one I have has a lot of curves, 4 plastic pins that go into the switch, and spring loaded white plastic barbs that prevents the assembly from falling out of the mounting hole. I think the model is SF21. For someone who's never designed a 3D part, seems like a frustrating part to make! The ones I saw just now at Digikey appear to be a different style, possibly a newer one.Incidentally I happened to find some obscure website selling all sorts of salvaged stuff and they had a used switch like this with the endcaps for under $20 so I'm giving that a shot. Never heard of them but it seems legit.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: June 09, 2025, 06:27:19 pm
content: A part like that can be tedious, but not particularly hard. Remember that in the era that switch concept was developed some guy with a straight edge, compass and french curve drew itPlacing the part on a scanner and then tracing/overlaying the scanned image is probably the easiest approach.Good luck with your surplus find.

author: JacobPilsen
author_rank: Regular Contributor
timestamp: June 09, 2025, 07:20:56 pm
content: https://www.ckswitches.com/products/switches/product-details/Thumbwheel/3/https://uk.farnell.com/c-k-components/413402000/front-mount-end-plate-thumbwheel/dp/4336893

author: floobydust
author_rank: Super Contributor
timestamp: June 09, 2025, 07:34:12 pm
content: Sometimes you can get lucky here:Nebraska Surplusthere are some Unimax and Digitran but can be expensive.C&K/Unimax is a separate catalog. An older C&K Switchescatalogsbut little mention of Unimax.

author: jrmymllr
author_rank: Regular Contributor
timestamp: June 10, 2025, 07:16:12 pm
content: Quote from: JacobPilsen on June 09, 2025, 07:20:56 pmThat's a different part, looks more recent.

author: jrmymllr
author_rank: Regular Contributor
timestamp: June 10, 2025, 07:20:42 pm
content: Quote from: floobydust on June 09, 2025, 07:34:12 pmI actually found the ones on NE Surplus, but no endplates. Interesting store by the way. And looking at the catalog you provided along with other info I found, it's the SF series. I love archive.org.I bought a salvaged 3 digit unit from gridchoice.com. It's on the way. We'll see how that works out but I'm optimistic. I think it's cool online stores like this still exist.