4 ms·

Is there some set of standardized benchmark objects that different companies and owners could print and compare? Maybe something that requires increasingly hig

Is there some set of standardized benchmark objects that different companies and owners could print and compare? Maybe something that requires increasingly high precision as a function of volume so you could say "my machine goes out-of-spec at 3 cm^2"?

jacquesm 12y ago
With the amount of slop and the kind of drive used (steppers) going out of spec is the norm, precision is mostly coincidential. If you don't use servos or steppers+encoders for feedback you may just as well assume that anything that you produce is unique. The variability in wire-feed (gripping wire is a tricky proposition) and head temperature adds to this. The result is a fairly rough surface (compared to millwork or lathework) but in the end what matters most here is that it can be done at all. If you require precision then you're probably going to have to do a little bit of re-work (just like you would with casting), if all you care about is looks then you may have to do some sanding to get a really smooth surface. 3D printing right now does not allow fabrication to the same tolerances that we have gotten used to with even minimal metal working tools unless you are prepared to reach very deep into your pockets. See above about renting, good quality equipment can be rented for a fraction of the cost of buying bad quality equipment and will produce workpieces that are very good due to the tight control over the head position and the increased control over wire feeds and temperatures. Consistency (feeds, speeds, temperatures, materials) and precision (accuracy of position, repeatability) are flip sides of the same coin, you can't really have the one without the other, and when both are good then you will have good quality workpieces. If either is not so good then you will end up with rough work, low quality and/or a lack of precision. Not all work requires precision or good surface finish, it is rare to have work that requires neither.
- MrBuddyCasino 12y ago
  A.k.a why not just use Shapeways. The level of detail they are capable of is very impressive: http://www.shapeways.com/model/1987984/tribal-voodoo-skull.html?li=ds.302920.11 http://www.shapeways.com/model/1987984/tribal-voodoo-skull.h... I don't now a lot about 3D printing, are there any serious competitors?
joshvm 12y ago
The Formlabs rook (the one with the helix in the centre) is pretty good, but it's difficult to find an STL for it.

jacquesm 12y ago

With the amount of slop and the kind of drive used (steppers) going out of spec is the norm, precision is mostly coincidential. If you don't use servos or steppers+encoders for feedback you may just as well assume that anything that you produce is unique. The variability in wire-feed (gripping wire is a tricky proposition) and head temperature adds to this. The result is a fairly rough surface (compared to millwork or lathework) but in the end what matters most here is that it can be done at all. If you require precision then you're probably going to have to do a little bit of re-work (just like you would with casting), if all you care about is looks then you may have to do some sanding to get a really smooth surface. 3D printing right now does not allow fabrication to the same tolerances that we have gotten used to with even minimal metal working tools unless you are prepared to reach very deep into your pockets. See above about renting, good quality equipment can be rented for a fraction of the cost of buying bad quality equipment and will produce workpieces that are very good due to the tight control over the head position and the increased control over wire feeds and temperatures. Consistency (feeds, speeds, temperatures, materials) and precision (accuracy of position, repeatability) are flip sides of the same coin, you can't really have the one without the other, and when both are good then you will have good quality workpieces. If either is not so good then you will end up with rough work, low quality and/or a lack of precision. Not all work requires precision or good surface finish, it is rare to have work that requires neither.

MrBuddyCasino 12y ago
A.k.a why not just use Shapeways. The level of detail they are capable of is very impressive: http://www.shapeways.com/model/1987984/tribal-voodoo-skull.html?li=ds.302920.11 http://www.shapeways.com/model/1987984/tribal-voodoo-skull.h... I don't now a lot about 3D printing, are there any serious competitors?

joshvm 12y ago

The Formlabs rook (the one with the helix in the centre) is pretty good, but it's difficult to find an STL for it.