Request for two small steel rod-esque lathed part!

**HankMcSpank** · 19-06-2009

Originally Posted by Hemsworthlad

Do you buy the magnets in 20mm lengths or as a bar and cut it to required size?

that's my next challenge...yes, i bought them as 20mm lengths (this is the only length I can find in 5mm dia) - i've bought some diamond cutter discs for my dremel...& intend using my cnc mill to cut them as they stand vertically while spraying the magnet with water mist! (from an airbrush!)

**HankMcSpank** · 19-06-2009

Originally Posted by Hemsworthlad

small lathe required:naughty:. . . . much easier. . . . . and cheaper

Yes, that's beginning to dawn on me. You'll gather that I'm the kind of guy that'll try & knock something he needs ala scrapheap challenge, but I think a lathe is beyond my ability! I'm now scratching around wondering what I can sell to placate my wife if I do utter the unmentionable under my breath "I think I need a lathe honey" ...it's likely to be a kidney. It'll then likely cost me double as she goes out to spend the equivalent (shoes, clothes, food - other unecessary stuff

)

**HankMcSpank** · 19-06-2009

Ok, I said they'd be bad - it's about the only commitment I can meet!

Hopefully, this will help visualize what I'm aiming for....

& here's a recent coil prototype...

It quickly became apparent, I need a better bobbin (those are sewing machine Bobbins bought from Boyes, Whitby @15p each! The diameter is (ar too wide & the centre hole is just over 6mm ...but then I'm into the domain of specialist bobbins (min order 1000s!). Then I thought, actually because space is so tight (the pickup from top to bottom must come in at less than 9mm in height - see cross section sketch immediately above), then I really ought to dispense with the bobbine completely - this is when my probelms started ultimately ending up here throwing myself at the mercy of the forum!

**HankMcSpank** · 19-06-2009

Cool - that rig actually looks very good (see what you mean about the 9mm diameter - that'd be fine)

When you mount the larger holder in a chuck, how does it turn overall? In my simplistic head, I just can't imagine that it'd turn 'true' ....as it looks like the opposite part would potentially cause wobble, (ie if it was out of alignment slightly?)

Like I say, I could be wrong!

re measuring those magnets I have...I only own one of those ubiquitous simple digital micrometers (allegedly measuring to 0.01mm accuracy)...it's not the best thing in the world (that said, in the main it suits my simple needs), but they all seem to be coming in at 4.96 - 4.99mm (that variance is more likey to be the inconsistent pressure I'm applying on the micrometer thumbwheel!)...I doubt any would come in over 5mm (on the basis it's cheaper for them to make smaller than larger!) ...& I reckon this simple coil making rig could withstand error of up to .2mm 9ie that's just 0.1mm slack either side of the magnet)

**HankMcSpank** · 20-06-2009

For once on a forum I'm chuffed to be wrong - Dean that's brilliant.

If you say the runout wasn't bad & can be (essentially) adjusted away, then that's good enough for me.

I'll drop you a PM.

**Ross77** · 22-06-2009

How dose that pick up work? if I may ask. coil winding is next on the list of machines to build. after mill, router, raduis machine and inlay cutter....

Are each of the coils feed back to amp/processor individualy or are they conected in series for better string balance?

Sorry to interupt the thead..

**HankMcSpank** · 22-06-2009

Originally Posted by Ross77

How dose that pick up work? if I may ask. coil winding is next on the list of machines to build. after mill, router, raduis machine and inlay cutter....

Are each of the coils feed back to amp/processor individualy or are they conected in series for better string balance?

Sorry to interupt the thead..

No probs...I've been scant with the details because after all, this is more of a mechanical-centric forum than an electronics forum. The small coils I intend winding aren't actually pickups (I used the term as it was simpler!).

These coils will actually be sustainer coils. The intention being to keep the guitar strings sustaining as long as the player wants them to. It does this by tapping off the guitar's standard pickup output signal, amplifying it & feeding the signal into these coils...this creates a varying magnetic field...& the guitar strings are ferrous so react to the mahgnetic field.

the coil is the easy bit...the tricky/creative bit is coming up with a good circuit to drive the coils!

re the pickup winder...it really is a heath robinson, but essentially it's a main motor, with an encoder disk mounted on iT (a CD label containing a lot of black/white stripes). I created an electronic circuit to synch the main motor with a stepper motor (buy counting the black stripes). It's via the shaft of the 'synchronized' stepper that the enamelled copper wire feeds onto the coil core.

Because there is so little room to fit my sustainer device (I don't want to route the guitar body), I reckonedthat the only way forward for these coils was to go bobbinless (coils/pickups are normally have a bobbin, upon which the copper wire is fed onto...but the bobbin itself takes space). That's when I had to throw open my plight to this forum...Dean kindly offered to get involved & help out.