Request for two small steel rod-esque lathed part!

**John S** · 18-06-2009

In the latest Digital Machinists magazine there is an article on a small coil winder by Weston Bye.

If you want I'll scan it later tonight [ got 102 winch levers to keyway this afternoon - aahhgg - crap job as they are a blind bore ] and can't play....................

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**HankMcSpank** · 18-06-2009

Originally Posted by John S

In the latest Digital Machinists magazine there is an article on a small coil winder by Weston Bye.

If you want I'll scan it later tonight [ got 102 winch levers to keyway this afternoon - aahhgg - crap job as they are a blind bore ] and can't play....................

.

hi John,

that'd be interesting, but only do it if you're at a loose end....my coil winder is done (could have done with the article 4 months ago!) ...but I'm always interested in stuff like this (it'd probably draw in a few people onto this site if Google steers them this way too)

**BillTodd** · 18-06-2009

Interesting coil winding thread on the 'zone
[ame="http://www.cnczone.com/forums/showthread.php?t=2497"]CNC Coil Winding Machine - CNCzone.com-The Ultimate Machinist Community[/ame]

**HankMcSpank** · 18-06-2009

This might help you visualize it...note though, that it's just been lashed up temporarily to photograph for that purpose! (especially the M8 threaded rod aspect!)

Just for illustration (& give some sense of scale), I've placed the magnet in the drill chuck jaw...presently the magnet is 20mm long, but it will need to be cut down in length to be 7 or 8mm.

After I've got the bits needed ...part 1 (as per my sketch further up), will be held by the drill chuck, the 5mm dia magnet will then be placed into part 1's end pocket/recess & part 2 will be forced up against the other end of the magnet (forming a a 'virtual bobbin for the copper to wind back/forward in between)....part 2 will rotate with the M8 threaded rod supported in turn by the bearings you can see in the photo.

I originally thought to use the M8 hex coupler you see in the photo to join part 2 onto the threaded rod, but I guess part 2 itself could have an M8 threaded hole in that end, which would eliminate the need for the coupler - not sure what's easier from a 'making' aspect? (a tapped whole or a 8m rod with an M8 thread cut into it)

**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..