Glowforge Software – Precision of Parts

qa

#1

I understand that a user will not be required to know anything about CAD/CAM software or its usage to create drawings that can be cut or engraved on the Glowforge. That’s all good. But what about those users that do know a little CAD/CAM and would like to have the ability to fabricate parts that carry more precision than a picture of a house drawn with a marker on a piece of acrylic. Will the Glowforge be able to take a 2D or 2.5D CAD generated drawing and cut a part that is accurate to, say, .001” on the XY plane? Will the Glowforge software do the equivalent of what a piece CAM software does for an endmill on a CNC mill application and offset the actual cut to correct for the width of the tool? In the case of the Glowforge, will the part be cut to the specification of the original CAD drawing (+/- the tolerance) accurately adjusting for the width of the kerf/width of cut, or the original CAD drawing less half the width of the cut?


HOWTO: Kerf Measurement and Jig
Adjustment for Kerf
#2

Lasers are a bit less predictable than a mill. One problem with lasers is that the kerf is not always the same. Different materials behave in different ways and thus have different kerfs. That being said, when you make line drawing and feed it to the GF, you can identify pieces of the material as ‘scrap’ or ‘not-scrap’. When doing so, the GF will offset the cut-line in the same manner as a mill does - thus accounting for the kerf of the laser.
GlowForge will be opening a materials store selling materials that have well understood and predictable cutting properties. As a result, you will be able to get accurate parts without your own testing. As far as tolerance of final parts, that is a question for @dan


#3

@Brandon is dead on. We’re not quite sure how consistent we can get kerf prediction for our known materials, which is probably going to be the limiting factor - but it’ll be, at most, a few thousandths of an inch. I’m hoping we can get it to less than a mil.


#4

@dan Wouldn’t it be beneficial to code an “advanced tab” feature into the CAM aspect of the cloud software where the user could manually make an offset adjustment for the kerf of a cut relative to the edge of the part? This is exactly what CAM software does when it adjusts for tool diameter when generating a toolpath for a milling operation.


Compensating for kerf?
#5

Sorry if I was unclear - that is exactly how it will work for non-Glowforge-provided materials.