[bigred8080]

Hey Guys,

I finally got my new acme lead screws installed and everything put back together. I jumped right in and engraved some acrylic. While from a distance it looks okay, when you get close, you can see where something seem off. in the picture below, you can see how in some parts of the lettering, it almost looks hand engraved. The C's seem to have the most apparent issues. The outside portion of it isn't perfectly rounded, and in one of them, the inside portion is almost touching the outside (because the outside isn't rounded right). The lines in the logo at the top seem a little shakey, but that may be due to the tracing having some chatter in it.

I have a MDF build (buildyourcnc.com book build)

RPM = 10000 ish
IPM = 40
depth = .01"

any help would be great!

Thanks
BR

[ger21]

The lines in the logo at the top seem a little shakey, but that may be due to the tracing having some chatter in it.

#1, you need to start with a clean CAD file. Garbage in, garbage out. If you're working from an auto trace of an image file, you're not going to get good results.


If you have good, clean g-code, then it comes down to machine rigidity. Build your CNC machines are not very rigid. with the machine off, and no tool in the spindle, grab the collet, and push and pull on it. If it moves at all, then you'll have issues getting clean cuts in acrylic. What you might want to do is take a very shallow, final finish pass, which can clean up any roughness.

[bigred8080]

I used v-carve to produce the trace and the lettering.

about the machines rigidness...yes, i know this ha. but, currently, it all i have to work with. While i reassembling the z motor, i noticed there was some slight movement so i made adjustments to remove this. I mean i could move it if i really want to, but for the most part, it doesn't move. Ill try to "measure" how much it moves with a "given" force ha.

I will take your advice on the making the finish pass and see what results i get (I wasn't aware you could do this ha). Would slowing down the machine do me any good?

[JQ_Quint]

I used v-carve to produce the trace and the lettering.

I think the point ger21 is trying to make is, is the quality of the cad data into the cam software good? If your putting faceted circular lines for example into c-carve then that's what you will produce. Does the cam tool path when zoomed in on the screen look like the final machined result?


Sent from my iPhone using Tapatalk

[ger21]

Yes, imo any auto traced image file, regardless of the software, will result in a poor quality carving, at least in acrylic.
If you want better results, you need to redraw everything yourself, so everything has clean lines.