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Old 14th Oct 2017, 8:34 pm   #9
David G4EBT
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Join Date: Feb 2003
Location: Cottingham, East Yorkshire, UK.
Posts: 5,737
Default Re: Making replica wooden knobs on a lathe

Thanks for reading guys, and for your kind comments.

Yes Dave, 3-D printers seemed to offer much promise but have rather gone of the radar screen of late.

From my very limited knowledge, looking at items in exhibitions that have been 3-D printed, I think the main shortcoming is the standard of finish, but in many cases, that may not matter as appearance will take second place to functionality. But knobs of course are on display, so getting a finish that's very close to the original may pose quite a challenge.

I was recently at the V&A where they were demonstrating a range sophisticated 3-D printers, way beyond the realms of DIY jobbies.

They were making all manner of complex objects, large and small. The larger ones used large nozzles to build the object quite quickly, then to get a good surface finish, switched to finer nozzles. However, even with the fine nozzles, the end result had small and distinctly discernable ridges where the filament was applied. I'm not sure whether - if knobs were made using 3-D printing - the plastic can be sanded and polished with burnishing cream so as to look like original Bakelite or plastic knobs - say like those for the Ekco A22 for instance.

The other issue might be matching the filament to original colours, though I guess most plastic radio knobs were made in fairly standard colours such as cream, green red, white, black, brown. If a full set of matching knobs is made, they don't of course need to be exactly the same colour and finish as the originals - only to each other.

for me to get into that, the equipment would need to be so simply to use that I'd just need to point a scanner at an object and say 'make one just like that'.

The other option is casting in resin - I've had a dabble at that, making moulds from original knobs using Alginate, but so far, with little success.
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