Cutting Rosettes with CNC Routers

Be careful CNC router spindle bearings aren't designed for a lot of plunge cutting. June 26, 2006

I want to be able to cut rosettes on my PTP. I do have a drawing program and I am about to try to use a standard rosette cutter of the kind you normally use on a drill press, which is how we normally do them. Is that a viable process? I would like to do them with individual bits so as to not stress the machine (I fear the vacuum holder will let go). Do any of you use this process?

Forum Responses
(CNC Forum)
From contributor G:
We have manufactured a variety of different rosettes for CNC equipment. If you currently have the tool, rpm's should be in the 3-5000 range. Depending on the tool, it may not be balanced for that rpm. Check with the manufacturer to see what the maximum rpm's are for that tool.

From contributor B:
Be careful. Most CNC spindles are not designed for vertical load on the bearings. Overuse making rosette blocks could damage the spindle. Perhaps with very slow plunge rates it would be okay, but be cautious.

From contributor S:
I'm with contributor B here. I've heard many horror stories about plunging with a router spindle. We make a few stiles with v-groove cutters and round-overs... Use your imagination. I machine 5 out of a 4x24 piece and chop them out later. Safe and productive.

From the original questioner:
Thanks for the responses. I tried the procedure with an off-the-shelf rosette cutter on alder. I tried different rpms and downward speeds. I obtained a beautiful, smooth cut at 12,000 rpms, .8 meters in two steps. Still, I would not ignore the advice you have given me. There has got to be a set of individual tools to accomplish this operation.