Speed up cutting time without losing quality?

Hey Guys

I’m just learning Meshcam before my Nomad arrives in December…

I’ve just done a test tool path using the parameters set out in Apollos Flip Frame tutorial, but it said it would take 67.6 minutes to cut per side.

Any ideas how I could speed this up?

Thanks Tim

I would say remove rought strategy

Your step over for the roughing is much too small. You can go up to 70, 80 or even 90% of the bit size for the step over - so .1" ish step over.

Also, you can speed up the feed and speeds for the roughing, assuming it’s hardwood. 50 to 60ipm feed would be fine.

thanks guys I don’t know what I’m doing yet :slight_smile: lol

Thanks Anton42 and Darren got it down to 22.4 minutes changing the roughing, feed and speed rates :smiley:

I’d point out that there are advantages and disadvantage to climb vs conventional milling, and also there are cases where going too slow or conservatively is actually worse for the work-piece and tooling than cutting too aggressively. Therefore I’ll recommend the following CNCcookbook articles:

Climb Milling vs Conventional Milling & 10 Tips for CNC Router Aluminum Cutting Success, which has some good general guidelines that apply to other materials as well.


Thanks Jonathan, will look at them now. On the plus side my flip frame arrived from the USA today!

In general I’d advise against more than a 50-60% stepover where roughing is needed. Depending on the geometry, MeshCAM might leave unmachined “pillars” where there is too little overlap on the roughing passes. That is more a concern in enclosed pockets, rather than the “open” geometry here. Just a heads-up.



Good point Randy. With a ball cutter you need to lower the step over. I should have clarified - if you are using a flat cutter, you can use a high step over value

The thing which I would really like to see is a physics-modeling G-code post-processor (or better still a CAM tool) which would actually calculate the speed at which the spindle was moving at a given point, the endmill’s rotation, and how much material was being cut, how Grbl was accelerating / decelerating the machine at that point and adjust the feedrate and/or spindle speed in the G-code for optimal chip size.

Reading a bit more, it seems that HSM (HIgh Speed Machining) is the front-runner for this sort of thing:


Anyone have a list of CAM tools which generate such paths?

Any hope of MeshCAM or Carbide Create being able to do it?

BobCAD-CAM does HSM. Their 3 and 5 axis packages do a fine job.

I use BobCAD-CAM 5 Axis Mill Pro so I can speak from experience.

BobCAD-CAM is known to bargain and have sales. Push them hard enough and one can get quite a deal. Even with a fantastic deal they are bit pricey…


@Darren, you are right, that in parallel ball-end finishing if you want a reasonably smooth surface you should set a stepover of 1/8-1/10 the cutter diameter to minimize the “cusping” (extensive discussions of this over on the MeshCAM forum). But this is a separate effect. See http://grzforum.com/viewtopic.php?f=3&t=15531 for a photo of the “pillars” left by the too-large-roughing-stepover effect.


Darren I will be using ball cutters