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Simso
20-06-2019, 09:04 AM
Hi folks,

So i am not a jeweller but a musical instrument repairer, lots of tools cross over.

Im stuck on how to do this one.

I need to make 4 brass replacement machine head (handles) for this guitar to allow tuning of the strings.

The existing ones were made from plastic and centre joined with glue, the centre has a 5mm square hole.

Im trying to be able to cast these as one piece if possible, just not to sure how to cast the shape with an internal square hole

3 photos,
guitar - missing machine head handles
One set of machine heads - these were glued around the square shaft
Two pieces together - my end casting goal

Thanks

Steve
Dennis
20-06-2019, 10:11 AM
You could cast them in to halves using the Delft Clay method (see online videos) and then sweat solder them together, or you could use investment casting by making them in wax, or using the originals as a pattern.
But considering the cost, if you have to buy in the tools, it would be cheaper to send them to a small items, or jewellery caster. Dennis
Simso
20-06-2019, 11:28 AM
Yes, deft clay cast and then sweating them together is an option i have thought, just checking if i have somehow missed an easier idea. I am set up already for this method in my workshop.

No idea on investment casting, or wax mold will do some research.

Steve
josef1
20-06-2019, 03:15 PM
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You could CAD them, have them printed then cast. But the cost would be high I guess. I suppose you could offer custom or personalised ones ?
ps_bond
21-06-2019, 06:08 AM
Cast as one piece, drill & use a square broach for the hole?
Or you could use a square piece of graphite as a core.
Or just get them lost-wax cast...
Simso
22-06-2019, 05:06 AM
Lots of ideas, this is a one guitar job only, so not worth the investment of purchasing a square brooch either.

I can cad draw it up, can also cnc route a block of brass and make seperate halves and sweat together.

Lots of ideas, might just deft clay cast each side up and see what it looks like, if that does not work i will cad and cnc route

Thanks

Steve
ps_bond
22-06-2019, 11:36 AM
Purchase? I'd just file one up...