Do you have access to a service manual for the Yamaha FC3 pedal?

I’ve got two of these dogs and it seems the pots are failed on both of them.  I know they are 10kB pots but I haven’t been able to locate a direct replacement (12mm D-shaft, I think).

I was hoping the service manual would have a part number.

The pot has such a small travel as the pedal is pressed, I’m surprised the design works at all!

Sorry, I don’t have access to the FC3 service manual. It does show up on eBay.

I wonder if the built-in pedal section of the MFC10 uses the same pot as the FC3. You can download the manual for the MFC10 here:
https://elektrotanya.com/yamaha_mfc10.pdf/download.html
See page 32 of the PDF, reference number E40a. It’s a 10k pot with “B” taper (linear). Yamaha has tended to use ALPS switches and controls over the years. The RK163111 is an ALPS number, although that just indicates the series, not the specific pot. You should be able to search for ALPS info online and perhaps find a pot which matches the physical and electrical specs of the one in the FC3.

Contact info for parts, including US toll-free number:
https://usa.yamaha.com/support/parts_manuals/index.html
Help may or may not be available under current conditions.

My reply timed out on the screen.

Anyway, thanks!
The part# RK163111 seems like it could work.

Does it seem weird that the pedal uses such a small part of the pot’s range?

You’re welcome, I hope the information helps.

The Yamaha part number shown in the MFC10 SM is VV042000. If you want to order from Yamaha, you’d have to verify with them whether that number is valid for the FC3 as well. The ALPS info might be useful if you look elsewhere for the part, but there’s more to that number that will describe the resistance, shaft length, etc.

The shaft of a typical single-turn pot can rotate about 270 degrees, but of course that wouldn’t be practical for direct connection to a pedal. Manufacturers can either use a mechanical arrangement to have a small pedal excursion turn the pot close to full possible rotation, or they can design the pedal input circuit so that a change in pot resistance value over a narrower mechanical range works correctly. Either type of design has pluses and minuses.

I just ordered a MODX8.  😀

BobosCurse - 08 May 2020 05:21 PM

I just ordered a MODX8.  😀

Since that has nothing to do with the subject of this thread, I suspect you meant to post it in this thread:
http://www.motifator.com/index.php/forum/viewthread/480681/

Motifator doesn’t support the MODX. Have fun with your new toy.

That is WEIRD because I was in the other thread when I posted!!

Why doesn’t the site support MODX?

BobosCurse - 08 May 2020 09:29 PM

That is WEIRD because I was in the other thread when I posted!!

Hmm…

 

BobosCurse -

Why doesn’t the site support MODX?

The basics:
http://www.motifator.com/index.php/forum/viewthread/480696/

An earlier thread with more depth:
http://www.motifator.com/index.php/forum/viewthread/479059/