Motor for Guitar Tuner

Thread Starter

The_Fleertz

Joined Apr 23, 2012
8
Hey all,
I need a DC servo for an automatic guitar tuner and was wondering if anyone had suggestions for one that would have sufficient torque and be easily controlled using a PIC16f887 and an H-bridge. No RC servos though.
 

MrChips

Joined Oct 2, 2009
30,714
What does a servo motor got to do with a guitar tuner?
Are you attempting to tune the guitar strings with a motor?
I think the required torque is going to be extremely high.
 

wayneh

Joined Sep 9, 2010
17,496
I think the required torque is going to be extremely high.
Not with the mechanical advantage of the tuner mechanism. My old fingers have no problem.

Also, I had my guitar in the shop recently and saw the technician use a motorized winder to speed up a restringing. He just slipped it over the the tuning knob and spun it like using a cordless screwdriver.
 

MrChips

Joined Oct 2, 2009
30,714
Winding up the string is one thing, tuning to a precise musical note is another.
I am a musician and guitar player. I know what it takes to tune a guitar.
 

wayneh

Joined Sep 9, 2010
17,496
Oh I'm not saying it's a simple idea to implement, just that it could be done. The tuning process takes a skilled hand, but I think a computer could do it as well as a human. A device that matched your guitar and could tune all 6 strings at the same time would be pretty cool. I'm sure I'd never pay for one, but I'd want one.
 

MrChips

Joined Oct 2, 2009
30,714
A better idea would not require a perfectly tuned guitar. Play a note and a DSP plays back a perfectly tuned note, chord, chorus or whatever for any instrument of your choosing. Like a keyboard synthesizer.
 
Last edited:

Sensacell

Joined Jun 19, 2012
3,432
You just need a small DC motor with a large reduction ratio gearbox, super low speed, high torque.

Backlash is always an issue, but that's another story.
 

GetDeviceInfo

Joined Jun 7, 2009
2,192
tuning and winding would be substantially different operations. I have a handy electronic device with three lights. I select the note and tune to the lights. Can't imagine a motor improving that simplicity. Winding maybe, but I usually don't put on more than 4 winds as an anchor. For continous fine tuning, a thermal 'motor' might be considered. Someone suggested passing current through the string to create a thermal response.

As I see it, speed for winding is a contradiction to precision for resonance.
 

wayneh

Joined Sep 9, 2010
17,496
I select the note and tune to the lights. Can't imagine a motor improving that simplicity.
I can only speculate that the OP wants to automate the process, to take the "I" out of it. A minimum-wage roadie could then produce a perfectly tuned guitar without knowing jack about it.

Someone suggested passing current through the string to create a thermal response.
Hah, yes I've "enjoyed" current passing through my microphone to my lips. Certainly changed my tune!
 
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