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DIY Stompboxes => Building your own stompbox => Topic started by: Octavian on January 13, 2016, 05:39:56 PM

Title: Sources for very small potentiometers?
Post by: Octavian on January 13, 2016, 05:39:56 PM
Looking for a few different types of pots, and I'm having trouble finding places to buy them.

The first is a thumbwheel pot (kinda like these http://www.top-up.com.tw/front/bin/ptlist.phtml?Category=60653 ) in various values (really if I could get A50K and B50K I could deal with it) and, preferably with numbers printed on them.

The second is something like this (http://www.top-up.com.tw/front/bin/ptdetail.phtml?Part=9PM1VF-D&Category=251925) or maybe something else that would give me a very short (maybe 5mm max) long shaft with a very compact body - trying to fit this in a very small space!

The third, and I don't even know if these exist, is a very small (doesn't need to be quite as small as the others, but no bigger than an inch or so square) dual axis joystick pot without a center spring.

Everywhere I look for these kind of things either has a huge minimum (most parts suppliers) or lists it but doesn't actually carry them (mouser, digikey, etc)

TIA!
Title: Re: Sources for very small potentiometers?
Post by: dschwartz on January 13, 2016, 08:22:16 PM
Sorry i can't help..just want to rant.."why the hell is so hard to get small or vertical pots "????
Title: Re: Sources for very small potentiometers?
Post by: stallik on January 13, 2016, 09:01:58 PM
AliExpress if you don't mind ordering from China... Lots of 5
Title: Re: Sources for very small potentiometers?
Post by: smallbearelec on January 13, 2016, 10:53:42 PM
Re your second request, maybe these:

http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-9mm-right-angle-pc-mount-w-knurled-plastic-shaft/

Re the thumbwheels: I did not realize that they might be of interest for pedals, will consider adding them if other people want. It is very helpful in this respect if I get a request from a decent-size pedal boo-teek wanting a particular made-to-order style. That is the way it is with these items: A pot- or switch-maker like Alps, Alpha or any of many other shops has a catalog with thousands of possible variants. The ones that you see on a distributor shelf represent some MBA's guess at what will move. I target a niche, and I am always listening for ideas. When physical space and investment $$ permit, I add line items. Stay in touch...

SD
www.smallbearelec.com
Title: Re: Sources for very small potentiometers?
Post by: stallik on January 14, 2016, 01:17:02 AM
Hmm. Just how many of these pots could you cram into a 1590a? Without needing to leave any room for knobs
Title: Re: Sources for very small potentiometers?
Post by: PRR on January 14, 2016, 01:53:23 AM
Back in the 1960s, thumbwheel pots were available in several values.

However the main use was transistor radios, and they all tended to use 5K.

I have not seen any value other than 5K in a thumbwheel in many decades.

If you want to pay to stop the line for a day, run off many-many test samples to get the carbon-ink right, then buy enough good parts to make it worthwhile for the factory, you could get any reasonable value. (25 Ohm or 1Meg may be unreasonable at that size.)

If you find where all the unsold 50K thumb-pots from 1963 were stored and forgotten, then the only problem is they may want you to take ALL of them.

With amplifiers, at some level, you "can" re-design the amplifying circuit to use any pot-value you can get. Sometimes this even leads to a nicer design, though often more expensive.

Trimmer pots can be small and "can" have knobs added. Problem is that a knob-pot is expected to last 5,000++ turns, a trim-pot not even 100 turns. But they are cheap. If you can figure a dead-easy way to replace the trimmer between shows, on the bus from Tulsa to Albuquerque, it may be viable. 
Title: Re: Sources for very small potentiometers?
Post by: Octavian on January 14, 2016, 10:44:50 AM
Quote from: smallbearelec on January 13, 2016, 10:53:42 PM
Re your second request, maybe these:

http://smallbear-electronics.mybigcommerce.com/alpha-single-gang-9mm-right-angle-pc-mount-w-knurled-plastic-shaft/

Re the thumbwheels: I did not realize that they might be of interest for pedals, will consider adding them if other people want. It is very helpful in this respect if I get a request from a decent-size pedal boo-teek wanting a particular made-to-order style. That is the way it is with these items: A pot- or switch-maker like Alps, Alpha or any of many other shops has a catalog with thousands of possible variants. The ones that you see on a distributor shelf represent some MBA's guess at what will move. I target a niche, and I am always listening for ideas. When physical space and investment $$ permit, I add line items. Stay in touch...

SD
www.smallbearelec.com

Thanks, but how long are the shafts on those?

--

Was thinking about finding / making new knobs for those 100k trimpots that have a knob (the blue ones), but like PRR said, reliability is a concern.
Title: Re: Sources for very small potentiometers?
Post by: smallbearelec on January 14, 2016, 08:58:17 PM
Quote from: Octavian on January 14, 2016, 10:44:50 AM
Thanks, but how long are the shafts on those?

http://diy.smallbearelec.com/Library/Mechanical%20Drawings/Alpha9mmPlasticShaft.pdf
Title: Re: Sources for very small potentiometers?
Post by: duck_arse on January 15, 2016, 09:04:11 AM
this, just in (three lines down).

https://www.rockby.com.au/Rockby/Mailer/CLEAR036_3.htm

the rest of their specials are always an interesting read.
Title: Re: Sources for very small potentiometers?
Post by: Octavian on January 15, 2016, 10:43:16 AM
Quote from: smallbearelec on January 14, 2016, 08:58:17 PM
Quote from: Octavian on January 14, 2016, 10:44:50 AM
Thanks, but how long are the shafts on those?

http://diy.smallbearelec.com/Library/Mechanical%20Drawings/Alpha9mmPlasticShaft.pdf

Thanks, actually found the specs online and bought a test batch yesterday.