Centroid Community CNC Support Forum

Good to know, I've kept smoothing on as a default in Fusion as there's a note about it cutting down on file size substantially.

Does your comment apply to CNC12 smoothing as well? Or just Fusion smoothing?

In what scenario should I be looking to enable smoothing?

Here's a link to the Centroid Acorn smoothing users manual. It has a lot of goof info in it for you. It explains most everything but let us know if you have more questions. As Keith said for simple geometry smoothing should be off in Acorn. I don't use Fusion so I can't tell you anything about the smoothing in Fusion.

https://www.centroidcnc.com/centroid_di ... manual.pdf

cnckeith wrote: ↑Sat Sep 03, 2022 7:51 am This type of geometry should not have any smoothing applied. It is unnecessary by having smoothing on. What you're asking fusion 360 to do is break up what should just be a nice straight line or an arc into tiny little pieces, lots of them causing problems. Then turning in CNC 12 smoothing then tries to turn those tiny little pieces back into smooth bigger arcs. Simple geometry like straight line squares circles arcs don't need any additional smoothing applied to them. The same with rigid tapping and drilling cycles. I would turn off any smoothing functionality in fusion 360 (or at least make the vector length controls much much larger. ) The subject comes up at least once a month on the forum where newbies misunderstand when to apply smoothing and when not to and what It is designed for I'll put together a diy smoothing paper as soon as I find some time to explain everything with graphics.

That would be great, this is a pretty interesting topic, as I am sure that many use Fusion360, and many probably have smoothing checked all the time. I run with smoothing in Fusion only. Maybe time to disable that, and run some tests.

Continued lackluster results cutting circles/holes. Latest project below - these were 1.05" diameter counterbores.

This was without smoothing enabled in either Fusion 360 or CNC12. Attaching the NC code here as well.

Any ideas how to improve this?

It cuts like this at any spot on the table?

Maybe try rotating that circle to see if the flat spots rotate to?

That might help confirm it’s software or PP and not mechanical?

ryanjg11 wrote: ↑Sun Oct 02, 2022 12:46 am Any ideas how to improve this?

Have you tried slowing things down? Your feed rate is 250ipm for this small pocket, you in a hurry? You may be exceeding the mechanical limits of the machine. Post a link to your Google photo album so we can see the machine. Is it one of those extruded aluminum frames?

Fast cutting and no finish pass. I suppose the flats are in the direction of the lead out after viewing the g code...

Also Acorn calculates the feed from the mid of the cutter, on small circles actual feed on the outside of the mill is much higher.

Uwe

suntravel wrote: ↑Sun Oct 02, 2022 11:39 am Fast cutting and no finish pass. I suppose the flats are in the direction of the lead out after viewing the g code...

Also Acorn calculates the feed from the mid of the cutter, on small circles actual feed on the outside of the mill is much higher.

Uwe

Uwe, my apologies as I only uploaded the finishing pass of a larger project. These holes were already cut in a previous operation leaving only .02 axial and radial material to be cut in these finishing passes.

ShawnM wrote: ↑Sun Oct 02, 2022 10:50 am Have you tried slowing things down? Your feed rate is 250ipm for this small pocket, you in a hurry? You may be exceeding the mechanical limits of the machine. Post a link to your Google photo album so we can see the machine. Is it one of those extruded aluminum frames?

ShawnM, I figured my machine would get nowhere near 250 ipm on these operations (as they're very small holes and my machine is current configured in CNC12 with a deadstart and delta vmax of 5.0 in/min). I have no idea if these settings are too aggressive, however. And yes, this machine is made from 80/20 extrusions so rigidity is a very valid concern.

One other PITA about going super slow is, of course, I'm too cheap to buy Fusion 360, so my rapid speed is limited to cutting speed. Making it all very slooooooow. I have the Wireless MPG and can easily speed it up, but I've noticed this also speeds up corners and other features which can cause a lot of jerkiness.

I've at least isolated this to only be an issue that occurs on diagonal or arcing moves. Upon closer inspection of some hexagonal holes yesterday, the walls along the X axis are perfectly smooth, yet the diagonals look terrible.

I think this rules out cutter sharpness and speed as an issue (correct me if I'm wrong).
It would seem this is only an issue when both X and Y are running at the same time, either doing diagonal straight moves, arcs or circles.

Attaching my latest CNC12 report zip file here, and a more complete NC file that shows the roughing and final pass for the pockets.

I'm running Clearpath SDSK servos, and this is a dual Y axis machine. Wondering if something is ever so slightly out of sync on my two Y axis. This machine has prox sensors at home, and I am auto-squaring and pairing each time I start up the machine.

==========

Did some further testing yesterday, cutting some holes at much slower speed and with different Deadstart and DeltaVmax settings (default at 5 in/min). Changed these settings to 10 and 20, no appreciable improvement. Slowed speeds down to 50 ipm and then even slower to 30 ipm, interior edge quality of circle did not seem to improve. This doesn't appear to be speed related.