First, I am not sure I am using the correct terminology. When I say “step over” I am referring to the amount that is cut again when the bit makes an adjacent pass. So…if I am using a 1/8" bit, it makes a cut 1/8" wide. When it makes a pass right next to the first pass, I believe it cuts 1/16" new material and 1/16" of the space cut on the last pass. 50% step over. On to my question…
Can the step over percentage be changed in Easel? How/where?
Thanks!
@NAM37
That was quick!
Am I correct in assuming that a higher percentage results in less new material being cut?
Thanks!
The smaller the percentage the less new material is cut. 100% would step over the full diameter.
Good thing I asked!
You know what happens when you assume! LOL
I’ve always assumed is was the percentage in relation to the bit size (I don’t think I’ve seen it specifically documented). So the smaller the step over the better the finish.
I just did my first test in acrylic.
I used the 1/8" single flute upcut bit from that came with my X-Carve. It cut fine but I am not satisfied with the finish. I thought I would start with the step over.
Any other suggestions?
Are you talking about the finish in the bottom of a pocket?
yes
Are you using a flat bottom end mill?
I am using this bit that came with my X-Carve -
https://www.inventables.com/technologies/solid-carbide-single-flute-upcut-end-mill
Judging from the pic on the web site it does not have a flat bottom.
Well, there’s your problem 
To get a good bottom finish you need a flat bottom tool.
Can you recommend a bit for this application?
How large is the pocket you are cutting? This is the tool I use for small pockets
http://www.ebay.com/itm/361219021028?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT
If you’re getting gouging or rippling in your pockets, make sure your spindle is perpendicular to your material both front-back and side-side. You may still see toolmarks after that but the wavy texture will clean up immensely.
Also, with acrylic make sure you’re keeping chips clear and your tool cool, so you may need to babysit the spindle with a vacuum just to keep air moving around. Heat is the nemesis of milling plastics. Heat melts the chips and they fuse to the bit, heat causes the material to flow out of the way of the bit as it moves through instead of being chopped away, and lots of other problems.
I did not have any gouging or rippling. I was blowing air on the cut so I don’t think that is problem.
The bit (provided by Inverntables) does not have a flat bottom. I suspect that is the source of the issue.
Can anyone recommend a plastic cutting bit that leaves a nice finish on the bottom?
I just looked at the link for the bit you are using and it does have a flat bottom. So your problem may be something else. Can you post a close up picture of the bottom of your pocket? If we can see the marks you are getting it may help figure out the problem.
As requested, here is a picture of my cut (extremely close up). I also included a picture of the bit. It is clearly NOT a flat bottomed bit.
it looks like you have a broken bit
Brand new out of the package from Inventables.
