4th axis for a reprap

I have been doing a lot of planning for the reprap I am building and had a thought about a 4th axis on the reprap that would allow you to make perfectly round objects. it would require a head and tailstock aligned in the x axis and some type of mandrel, either glass or your print material which would be rotated by another stepper motor.

I'm wondering, do you think that this ability would be of value to the community? has there been any work on this concept yet?

Thanks!

Clay

It's been talked about here a few times, I think some of the suspected problems have been:

hard to get rotational accuracy at large radii without gearing steppers down
difficult to program for (IMHO by far the hardest bit)
probably impossible to remove the mandrel
not necessarily better: printing a torus would still be tricky because the inside would need support material, like it would on a normal printer.

It'd be interesting though, and i'm sure there are some applications it'd be brilliant for. I would recommend starting with a normal printer though, so you have a bit of practice first.

Making a "perfect" algorithm for circles on a 3 axis bot would be a lot simpler and give equivalent results, IMHO.

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Generation 7 Electronics	Teacup Firmware	RepRap DIY

... a 4-th axis only isn't worth the fuzz ... but 4+5 (pan+tilt) will make a really big difference for printing without support and bridging/stringing all sorts of complex geometries!

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Viktor
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Aufruf zum Projekt "Müll-freie Meere" - [reprap.org] -- Deutsche Facebook-Gruppe - [www.facebook.com]

Call for the project "garbage-free seas" - [reprap.org]

RepRap Squad has been doing a design for the last year and a half pertaining to the 5 axis reprap. We have been designing it for pan and tilt as you mentioned. It is going to be up for physical development soon. I will put it on a post as soon as I have some physical models for you guys to see. To check out RepRap Squads current projects click on the link.

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