[TMToronto]

I will start by saying I am very new to CNCs and milling. I did however just complete my ATC build (Onefinity Woodworker CNC, Masso G3 controller, Jianken 2.2Kw 24000RPM ATC spindle), and am now practicing my F360 CAM skills while trying to determine appropriate feeds and speeds that match my CNCs hardware and tooling when milling various materials.

I plan to test a facing toolpath on HDPE, and while running an 'air' pass as a test, I noticed that the feed rate changes during each pass as the end mill accelerates and decelerates across the work piece.
I am noticing this now more as I am experimenting with increased feed rates.

My general question is what options there are to reduce this variation so that the feed rate remains more constant throughout the entire facing toolpath. I ask because I imagine in extreme cases it can/will impact the finish at the start and end of each facing pass.

I know I can alter the acceleration/feed rate settings in my controller, and in my CAM, but what do others do when they want to keep tooling fully engaged with the material at all times with a high feed rate during a facing operation.

I appreciate any advice and insights those with experience can provide.

[maxspongebob]

Do you have the acceleration values setup properly?
I am pretty sure the head should reach max velocity during the lead in and lead out process. Fusion will always try to keep the chip loading constant while the material is engaged.
I would us a feed/speed starting point that is provided by the tooling manufacturer. Then make changes from there. Also be careful not to fall into the trap of going too slow.

[mactec54]

I will start by saying I am very new to CNCs and milling. I did however just complete my ATC build (Onefinity Woodworker CNC, Masso G3 controller, Jianken 2.2Kw 24000RPM ATC spindle), and am now practicing my F360 CAM skills while trying to determine appropriate feeds and speeds that match my CNCs hardware and tooling when milling various materials.

I plan to test a facing toolpath on HDPE, and while running an 'air' pass as a test, I noticed that the feed rate changes during each pass as the end mill accelerates and decelerates across the work piece.
I am noticing this now more as I am experimenting with increased feed rates.

My general question is what options there are to reduce this variation so that the feed rate remains more constant throughout the entire facing toolpath. I ask because I imagine in extreme cases it can/will impact the finish at the start and end of each facing pass.

I know I can alter the acceleration/feed rate settings in my controller, and in my CAM, but what do others do when they want to keep tooling fully engaged with the material at all times with a high feed rate during a facing operation.

I appreciate any advice and insights those with experience can provide.

Check your control / software, some controls have this feature which you may have it set incorrect if it has it. normally this is for when the cutter is changing direction and not for straight moves, this is normally only in the control, Cam software does not do this.

[joeavaerage]

Hi,
I've always struggled with HDPE, its not that its hard or does not cut, but the chips 'weld themselves back together'.
I now use flood cooling for all plastics, just to get the chips out of the cutzone so they don't gum up the works.

The straight line acceleration is set by your software/controller.....Fusion just calls for the machine to accelerate at 'fastest possible acceleration' until it reaches its programmed G1 speed.
The 'fastest possible acceleration' is supplied by your software/controller.

Craig