Feeds and speeds story;

Tonight I was cutting out a Native American Bow for 4th grade school project. Designed it in Aspire, all toolpaths double checked. It looked like it would be awesome.

Went to the machine and loaded the gcode for the rough cut, through Chilipeppr. Took a while to load, but that’s not important right now.

Once it loaded, I double checked Zero, went up 2 mm and fired the Makita up. Pressed play and held my breath. The machine came to life with a roar. Within 1 min almost half of the first cut was done. SOMETHING was wrong, but I let it run, with my hand on the exit button.

Everything went awesome, until… it tried to lift the Makita. Missed a couple of steps, then missed again, etc… You get the picture. I shut her down and went to look at the code to see just what I did wrong. It had never cut that great and fast before.

When selecting the rough cut bit, I had accidentally left it on the default settings for inches instead of mm.

It had been cutting at 2540 mm/min. with no issues. However it was trying to lift the Z axis at almost 800 mm/min. The fastest I’ve ever been able to do the Z axis during trials was around 400.

I’ve been very conservative with my speeds, running an average of 500 mm/min on most cuts, or less. But now I think I can safely say she can handle way more than that.

This was on an old 12"x1" pine board with a straight cut bit. 6mm depth of cut, 40% step over with the makita set to 2. I just wouldn’t have imagined the machine being able to cut that fast with no issues. Is this normal? Have I been limiting myself way to much?

I have been cutting oak plywood. 1300 mm/min and 2mm doc in easel. Seems to do fine. With my sewalt that is. I’m scare to go faster as I get chattering. Maybe I am gonna slow and that’s causing the chattering. Lo

On a 12" piece the machine wouldn’t be able to accelerate enough to reach such a speed.

Although this isn’t an ideal solution, just this morning a new Feed Rate Override feature was unleashed for ChiliPeppr that would have let you save your job. You could have cranked down the feed rate dynamically during the job to save it. Here’s a walk through of the new feature.