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Electronics => Projects, Designs, and Technical Stuff => Topic started by: dardosordi on October 02, 2016, 05:53:20 am

Title: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:53:20 am
I needed one and decided to build it, why ?

1. They are expensive, hard to get (where I live) and also shipping would cost half its price.
2. Because its fun.
3. I can repair it if the pot goes bad.
4. Because I can!

I made it using some cogs from an old cd drive, the shaft came from an old radio tuner and a heatsink as the frame. The knob was recycled from an old CRT monitor.

It's actually 13 turns and works reasonably well, Im quite happy with it.  :)

Title: Re: DIY 10 turns pot
Post by: neo on October 02, 2016, 08:09:53 am
This may just be my own opinion but this is genius in its own right, i really like the way you did it, might even do it myself with how many pots i have lying around  :clap:
Title: Re: DIY 10 turns pot
Post by: ElektroQuark on October 02, 2016, 08:46:52 am
DO the original pot behave perfectly linear (or logarithmic) in the new arrangement? I thought they are not so "regular"along all the range.
Title: Re: DIY 10 turns pot
Post by: ebclr on October 02, 2016, 08:56:29 am
USD 1.68 shiped to argentina

https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033 (https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033)
Title: Re: DIY 10 turns pot
Post by: ZeTeX on October 02, 2016, 11:09:40 am
USD 1.68 shiped to argentina

https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033 (https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033)
Those are totally garbage they literally break after no-time use.
but those:
http://www.ebay.com/itm/1pcs-Bi-Technologies-10K-Wirewound-Potentiometer-7276R10KL-25-10-Multi-Turn-/151336206694?hash=item233c574166:g:vbkAAOSwo8hTqA6A (http://www.ebay.com/itm/1pcs-Bi-Technologies-10K-Wirewound-Potentiometer-7276R10KL-25-10-Multi-Turn-/151336206694?hash=item233c574166:g:vbkAAOSwo8hTqA6A)
those actually come with a metal shaft and they are really high quality and cost only 8.6 US$ including worldwide shipping, for a 10 turn pot those are cheap and good.

but other then that, op, really good job! 10/10.
Title: Re: DIY 10 turns pot
Post by: SeanB on October 02, 2016, 11:11:09 am
Used to be very common as a method to get finer resolution on a variable capacitor, like used to tune radio sets. Does nothing for linearity or resolution ofv the pot, you get what it had originally, but you can adjust the wiper very slowly to give a finer control of the position, and there is reduced friction on it.
Title: Re: DIY 10 turns pot
Post by: dom0 on October 02, 2016, 01:40:01 pm
Some variocaps even had these gears built-in. To avoid play when trying to fine-tune to a station they use split-cogs that are spring-loaded. That way you can make even the most miniscule adjustments with no problems.
Title: Re: DIY 10 turns pot
Post by: lowimpedance on October 02, 2016, 02:15:56 pm
This may just be my own opinion but this is genius in its own right, i really like the way you did it, might even do it myself with how many pots i have lying around  :clap:
Indeed a neat re-application of various bits  :-+.
Title: Re: DIY 10 turns pot
Post by: Farley on October 02, 2016, 02:58:24 pm
Nice work.

One feature available with this sort of configuration is the ability to drive a dial/pointer off of the pot shaft. A conventional 10-turn pot does not provide that option.

dardosordi - are you experiencing any objectionable backlash in the gear train?

Title: Re: DIY 10 turns pot
Post by: ZeTeX on October 02, 2016, 03:42:34 pm
Now get a 10 turn pot and make it 100 turns! haha
Title: Re: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:20:45 pm
Nice work.

One feature available with this sort of configuration is the ability to drive a dial/pointer off of the pot shaft. A conventional 10-turn pot does not provide that option.

dardosordi - are you experiencing any objectionable backlash in the gear train?


Thanks!

I have no 10 turn pot to compare it to, but compared against the same pot (I have another spare) it requieres less force and feels ok.


Title: Re: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:23:09 pm
DO the original pot behave perfectly linear (or logarithmic) in the new arrangement? I thought they are not so "regular"along all the range.

The original pot was log and it works the same (these are not real log pots, cf http://www.geofex.com/article_folders/potsecrets/potscret.htm (http://www.geofex.com/article_folders/potsecrets/potscret.htm) ). It actually works pretty well for its intended use a home brew lab PSU.
Title: Re: DIY 10 turns pot
Post by: jonovid on October 02, 2016, 05:23:18 pm
 Like your work. I do similar things, if I need a custom one off part.  10 turn pots
Quote
They are expensive, hard to get (where I live) and also shipping would cost half its price.
have you tried aliexpress? they have blue 10 turn pots and the 10 turn knob's too.
OR maybe with your custom one off part, you can try adding custom lighting. :-+ making a knob glow  lightpipe design  try adding a custom lightpipe down a transparent plastic axle so the knob will glow with led's. like a red , blue or green glowing dot on the knob. a another idea is the fixd axle with a outer rotating sleeve & ring. the knob face is stationary so you can add a tactile switch. but the outer ring moves.  just more ideas.
Title: Re: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:25:36 pm
USD 1.68 shiped to argentina

https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033 (https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033)

Those are half what I pay for a regular pot here. Im travelling to the USA in a bout a week becuase of my job so I'll get some parts when being there. But all in all, this was a fun project and it worked.
Title: Re: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:27:37 pm
Used to be very common as a method to get finer resolution on a variable capacitor, like used to tune radio sets. Does nothing for linearity or resolution ofv the pot, you get what it had originally, but you can adjust the wiper very slowly to give a finer control of the position, and there is reduced friction on it.


That is correct and its what I was expecting, but it will let my PSU adjust in 100mV steps (finer if I bother to do it carefully) so I call it a win.
Title: Re: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:29:46 pm
This may just be my own opinion but this is genius in its own right, i really like the way you did it, might even do it myself with how many pots i have lying around  :clap:
Indeed a neat re-application of various bits  :-+.

Thanks, it drives me crazy thinking about all the work and energy that went into manufacturing stuff that ends up in a landfill polluting the environment! Plus I get to distract myself from coding all day long :)
Title: Re: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:31:02 pm
Now get a 10 turn pot and make it 100 turns! haha

Haha, will not be practical for my application but if resolution of the 10 turn pot allows it then it may be useful for someone else.
Title: Re: DIY 10 turns pot
Post by: dardosordi on October 02, 2016, 05:36:27 pm
USD 1.68 shiped to argentina

https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033 (https://www.aliexpress.com/item/50K-Ohm-590S-2-503L-BOURNS-Rotary-Wirewound-Precision-Potentiometer-Pot-10-Turn/32674459760.html?spm=2114.01010208.3.2.CFMS4L&ws_ab_test=searchweb0_0,searchweb201602_3_10056_10065_10055_10068_10054_10069_10059_418_10073_10017_10070_10060_10061_10052_10062_10053_10050_10051,searchweb201603_6&btsid=b09e4175-4db6-4286-b320-27526c604033)
Those are totally garbage they literally break after no-time use.
but those:
http://www.ebay.com/itm/1pcs-Bi-Technologies-10K-Wirewound-Potentiometer-7276R10KL-25-10-Multi-Turn-/151336206694?hash=item233c574166:g:vbkAAOSwo8hTqA6A (http://www.ebay.com/itm/1pcs-Bi-Technologies-10K-Wirewound-Potentiometer-7276R10KL-25-10-Multi-Turn-/151336206694?hash=item233c574166:g:vbkAAOSwo8hTqA6A)
those actually come with a metal shaft and they are really high quality and cost only 8.6 US$ including worldwide shipping, for a 10 turn pot those are cheap and good.

but other then that, op, really good job! 10/10.

I needed a 5K log pot, but this one may come in handy for another project. Thanks.

Title: Re: DIY 10 turns pot
Post by: TheDirty on January 04, 2017, 06:14:56 pm
Bought a 3D printer recently.  I bet I could design a gear system with holder.  Maybe it's already done, I'll take a look.
Title: Re: DIY 10 turns pot
Post by: dardosordi on January 04, 2017, 07:17:27 pm
Bought a 3D printer recently.  I bet I could design a gear system with holder.  Maybe it's already done, I'll take a look.

That's a fantastic idea, I would love to see it!