Request for two small steel rod-esque lathed part!

**Ross77** · 23-06-2009

Ah. I see. sounds like a good project.

Is it the no.of turns and length of wire that makes it work? If so you could use a small square bobbin to reduce the wasted space between the coils and then you can drill them to suit the size of the magnet. no need for a fancy holder and hopfully reduce the height.

Just my 2 peneth

**HankMcSpank** · 23-06-2009

It's a combination of the current through the coils, coupled with the number of turns (ampere turns in fact). It's a fine balancing act at that too.

Too many coil windings = too high an inductance, which means the coil presents resistance to higher frequencies feeding into it. The higher frequencies are the thinner strings, less ferrous material in them, so they actually need more drive

Too few windings = not enough magnetic force presented at the strings...only way to compensate is to cranck the current up, but that saps the battery.

Re round vs square coils. Square would be better (as it goes, I'd already considered them...in fact, you wouldn't believe the amount of McSpank Grey Matter processor 'cycles' I've dedicated to this little project!), but my simple coil winder (a drill chuck) cant cater for winding anything other than circular shapes! In fact longer rectangular coils would be better still...slightly overlapping one another so no dead spots when bending strings etc.

Originally Posted by Ross77

Ah. I see. sounds like a good project.
Is it the no.of turns and length of wire that makes it work? If so you could use a small square bobbin to reduce the wasted space between the coils and then you can drill them to suit the size of the magnet. no need for a fancy holder and hopfully reduce the height.

Not sure I fully grasp what you're getting at when you say (re square bobbins) "drill them to suit the size of the magnet" nor how could this proposale "reduce the height" .....I'm all ears, could you put more meat on the bone?

**Ross77** · 23-06-2009

Not sure I fully grasp what you're getting at when you say (re square bobbins) "drill them to suit the size of the magnet" nor how could this proposale "reduce the height" .....I'm all ears, could you put more meat on the bone?

I may have misunderstood, but I thought you said that the magnets were different sizes which was causing problems with holding them? If you use a square bobbin then it could easily be shaped to suit the magnet size (or epoxy the smaller ones)

I was thinking of the small plastic box section that you get from model shops, if you cut to size and put a small bolt through with a washer on each end then you would have a former and be able to hold it in jacobs chuck......

With regards to reducing height I meant that if the square section utilised the availble space better then it wouldnt have to be as tall...

Is that better?

**HankMcSpank** · 23-06-2009

All the magnets are the same size 5mm rod (which will be the core of the coil), this bad sketch i did for Dean helps visualize...

(it's probably worth pointing out, that the above sketch was a simplified version of how it'll look....and only used for testing. The coils will not eventually be visible ...as I intend mounting them into some CNC milled perspex. The only bits you'll see arethe tips of the magnets protruding above the perspex holder)

**Ross77** · 24-06-2009

Did Dean sort you out?

Will you be selling any of them? Im always keen to try new ideas, but havent got the time to make my own yet. Can you wind inductors for Wha's with that machine? Just replaced the inductor in my cheap wha with a halo and totally transfromed it.......

Ive got a bit side tracked with this thread and just spent the last hour on Utube looking at pickup winding...

**HankMcSpank** · 24-06-2009

Originally Posted by Ross77

Did Dean sort you out?

Will you be selling any of them? Im always keen to try new ideas, but havent got the time to make my own yet. Can you wind inductors for Wha's with that machine? Just replaced the inductor in my cheap wha with a halo and totally transfromed it.......

Ive got a bit side tracked with this thread and just spent the last hour on Utube looking at pickup winding...

What's a Wha?!!

Dean is up to his eyeballs - when he offered to help it was conditional that I wasn't in a hurry. I'm not (& remember he's doing this for free!).

re selling them...this isn't a commercial venture...& to be honest, even if I wanted to sell them (which I can't imagine it being worthwhile!), there's still an awful lot of further experimentation done wrt the coils themselves (number of of turns, wire gauge, type of core material etc)....the final coil design is still some way off.

I have no real proper coil winding facilities...just something I've put together myself "Blue Peter-esque! ....a 48V DC cooling fan, an encoder wheel striped disk (the pattern which I downloaded off the net, then printed onto a CD label & attached to a CD...I then cut out the middle of the CD & mounted on the fan!), a DC motor PWM speed control circuit (based on t he good old 555 timer!)....an optical pickup cct (to read the encoder disk) and most importantly a little bespoke PIC program that I wrote (which took me yonks as I hadn't a clue about PIC programming!). Previously I've been winding the coils onto small sewiing machine bobbins...but they're too big...hence the need for wanting to wind straight onto the magnets.

**Ross77** · 24-06-2009

What's a Wha?!!

Wha wha pedal....(Wah Wah if your fussy)..........AKA voodoo chile intro
Dont want to interfer, but if Dean gets mega busy then I could have a go.
Just re-read the thread, sorry about the previous posts.

Is this Idea limited to just sustain? if the coils where energised from a PIC then could some strange new effect be created? Ie just sustaining certain strings for a preset time.............:dance: