Background: I recently started cutting out flat-pack furniture parts. I’ve been cutting 3/4" baltic birch (19mm) with a cheap compression bit for a while now, and I’ve recently started getting some chatter in the X-direction.
I normally cut at 150 IPM and .375" DOC which has been decent up until now for some reason. I’ll probably be going back to .25" DOC soon to fix the chatter, but the time of cut kills me to have to do 3 passes instead of 2.
I’m wondering if the bit I’m using is not rigid enough and if I should splurge on a better one? Amana/Whiteside? Or is the Makita spindle just not up for a .375" DOC? I know it’s not recommended to go above 1 diameter of the bit, but I also know the SO5 is much more rigid than it’s predecessors which makes me think it’s possible to do larger DOCs.
I can also start experimenting with some roughing/finishing passes but want to see if anyone has ever done a full DOC in 3/4" ply before and if so what sort of F+S do you use?
If you want to do full depth passes in plywood I would suggest a compression too which has a suitable flute length/orientation — I suspect an adaptive/trochoidal toolpath will help as well.
It’s like taking scoop cuts instead of going full steam ahead. Small little loops moving forward, as I understand it. CC doesn’t support it and I’m not super confident designing in Fusion yet (have a start-up license though!) to do it.
An adaptive toolpath would only add A LOT more time, not reduce it.
Have you replaced the endmill recently? They do go dull, especially the cheap ones. I’ve gone 0.375" DOC in ply with the Jenny compression bit, then did a finishing pass. I ran something like 150 IPM on my S5Pro with the C3D spindle which is more powerful than the routers.
Adding time may not be a concern for everyone. I am retired.
Tool wear is a concern.
Driving a bit through a narrow channel is not the best for bits. with an adaptive path for some reason, I am thinking you could speed up the feed to help compensate for time.
Yes, you’re not slotting (which I agree is horrible on a tool). But you’re likely going to increase the linear distance you’re cutting by a factor of 10 if not way more depending on how you constrain your adaptive toolpath. That would make up for any reduction that adaptive would have in tool life, if not exceed it.
The only time I will adaptive clear before a contour is if I’m really, really concerned about chip evacuation on something like a small aluminum project. But I do very often do multiple passes to clear out around a contour, then do a full depth finish pass.
This is probably what I’m going to do. .375" cuts with a finishing pass.
How much material do you normally leave for the finishing pass? I was thinking .05"-.08"? I was getting some decent chatter so I want to make sure none of those marks make it through the final pass.
