XCP chipload and feed advice and why aren't circles smooth?

Doing some test cuts here to try and figure out the optimum feed/speed… why is this not obvious and written down somewhere is frankly beyond me. I’ve broken bits, I’ve burnt and burnished them to all heck and created the finest dust ever seen by a CNC operator all at the default settings… which are apparently useless. So I’m doing a self directed test of feeds and speeds based on this chart here - Chipload Calculator | GDP Tooling.

Given that Inventables recommends doing cuts only 1/2 the depth of your bit is wide (aka this is not a truly pro machine as they would want you to believe) I’m doing depths at .18 inches on my 1/4 inch short flute compression bit from Bits-n-Bits. I think I’ve dialed in my optimum speed at between 165-175ipm with 80in plunge at 10,000 rpm. That gets me minimal chipload to not burnish the bit while not going so fast/with slow rpm to literally jam the bit in the material. This happened several times…

If these speeds/feeds/chiploads are even close to correct someone please tell me so or correct me.

Now I’m addressing the other elephant in the room. Curves… I drew a 2 inch circle in Easel as part of my tests. The machine is cutting out the circle as a plug (outside the perimeter of the object. The edges are not smooth. The best way to describe them is that they are low resolution, the computer can’t catch up with the x and y axis adjustments to make this anything but a ribbed surface. Am I crazy or is there a ghost in this system? Straight lines are smooth as can be, any angle any direction. Every curve I’ve cut in the last 3 months required lots of sandpaper or time on the drum sander to be acceptable…

Oh, it’s all 3/4 inch birch plywood.

Thanks in advance! Zak

easel sucks. Buy better software.

hold on a second, easel doesn’t suck!!!

it’s software that is to get the beginner started in working with a CNC.

It really does suck. If you have a machine as expensive as an xcare pro, you really should be using software that is capable of delivering pro results. That isnt easel. Easel cant make use or arcs, thats probably part of the reason the circles arent smooth. It could also be mechanical issues, but I would hope not seeing as how the pro is shipped assembled and should be pretty good out of the box.

Easel just has trouble with arches and radius, if you are looking for perfection maybe Vectric is better for you. I’ve been using it for years.
better yet, checkout fusion 360

Argh! For the price of admission Easel shouldn’t feel like I’m playing with pre-beta MacOS. Please explain how it is difficult for software to execute a nice curve if the machine is capable…

I have Fusion360, do some designing in that but haven’t taken the leap to connect the two to work together but it seems like that is next. Do you know if fusion connects direct to the XCP or do I have to export code and then use easel to run that code?

Again - for the cost there should be an instruction manual that has these answers because the cost of learning gets high fast with a pile of burnt bits and failed projects.

Dont use easel to run gcode produced in other software, it will still be limited to what it can do and arcs is one of those things. Picsender, UGS, CNCJS are all way better gcode senders.

1 Like

Just an FYI, GRBL does not truly support arcs either. If you look at the documentation and the firmware, you will see that GRBL takes arc commands and extrapolates that into extremely small linear segments. So, even if you use Fusion 360 to generate arc commands, GRBL will not truly generate control the machine to that arc specification.

This is just an FYI, so let’s not get into arguments over it… :slight_smile:


Brandon Parker


This topic was automatically closed 90 days after the last reply. New replies are no longer allowed.