After a alot of help and maybe a bit of advise too..... Help, basically!

[bobtheboater]

Hi Guys and Gals, after some advise. Hopeful someone can help
Hi, i have a gearbox im buidling for a scale model and i need a duplicate or 6 of a gear i already have, the manufacturer (original) is long gone, so getting a genuine part is impossible, is it possible to scan (using terms i use sorry) the existing part and 3d print a replacement? is there anyone out there who does this?

any help / advise / thoughts greatly appreciated

[cbernhardt]

What size is the gear? Can you post a picture?

[bobtheboater]

its 31mm diameter and 10mm thick

[bobtheboater]

tried to upload a picture, not sure its worked

[cbernhardt]

If it is a simple straight cut gear you might look at a program called Openscad to create the gear rather than trying to scan it. The gear model below was created with their example program called "gears.scad". http://www.openscad.org/.
For some reason I also cannot upload a picture, so here is a link.
http://www.carols62.com/gears.jpg

[bobtheboater]

ok thankyou, im not sure if its simple or not, im kind of stuck with the project until i can get some gears, i hoped 3d printing duplicates maybe relatively simple

[cbernhardt]

By "simple" I meant a simple square cut gear. Here is a model of a 31mm x 10mm gear.
http://www.carols62.com/gear31x10.jpg

[bobtheboater]

yeah my gears are not square as in that image, sadly, if only it were that simple, is it possible for it to be scanned and duplicated?

[cbernhardt]

Your gear probably needs a high degree of accuracy in order to mesh correctly. I have limited experience with 3D printing, but what little I have would indicate that high accuracy is difficult to obtain. Perhaps others here could comment on that aspect.

If you have an original gear you may be better off trying to cast the part. Use a flexible silicone molding material to make a mold and perhaps an epoxy resin for casting the gear. I have used several products from Smooth-On.com for casting larger parts, but never tried something as small as your gear.

[curious aardvark]

piece of piss.
you can produce any shape gear teeth in openscad, and It will be quicker and easier than trying to 3d scan.

I have yet to find anything I can't duplicate with a set of digital calipers and openscad.