Hello everyone. I need some advice on feeds and speeds.
I am trying to bootstrap my lowrider v4 to be able to cut a torsion box table. It cut the holes fine, and after a bit change I started cutting the profiles. First pass went great, but on the second pass about halfway around the bit drifted off course.
I checked the preview in the software and the toolpath looks correct. I’m thinking it may be a speeds and feeds issue or tool problem.
I’m using a 1/4” straight flute cutter (too impatient to wait on the upcut bits) cutting in birch plywood.
My speeds are, from what I can remember:
2mm doc, 38mm/s feed, 25mm/s plunge, and 18,250 rpm.
Am I being too aggressive, is using the straight flute bit the issue, or is there something else I need to check on the machine itself?
I struggle to cut 5/8" fir plywood fast enough, to not dull the cutter, by hand in a single pass using a 1/2" straight flute cutter at 10,000 RPM (equivalent to 20,000 RPM with a 1/4" straight flute cutter).
What do your chips look like?
Is your chip evacuation working to remove heat from around the cutter?
What do your cut plywood edges look like?
The glue in some plywood does no miracles for cutting tools.
edit: Looking at the picture. I’d say work on getting the chips removed from the slot as you cut and feed faster (presuming your cutting tool is dulling). Or work on getting chips removed while you wait for 1/8" cutters and feed about the same rate.
Both of these seem a little fast for a new build. Check your core and make sure it has no wobble. Its normal for them to need a little tensioning after running the first few jobs as it sets the bolts into the core. Go very slow with tensioning the top 2 bolts. Just until there is no rocking in the core on the bearings.
The straight flute cutter isn’t helping your cause at all. The upcut will pull the chips up and out, straight wont. But I would try slowing down to 20-25mm/s and I would slow your plunge way down, like 10 mm/s Start a little slower and work up from there.
