Rosette cutter on PVC or go to the 'bot?

[jTr]

Anyone have experience using a drill-press mounted rosette cutter on PVC?
Should I go directly to running an extruder routine on the cnc?
Short run of 16 pieces 5.5 square, 1" thickness.

jeff

[myxpykalix]

It depends on what you want. Are you looking for speed or more design options? If you are only going to do a total of 16 why buy a large bit that is only going to give you a symetrical round button design. Here is a rosette i put on my wainscoting long ago

[jTr]

Low cost (read "speed") is the goal. Seems a cutter would be faster, but concern is with cut quality- will it chatter and get sticky? Looks like slow (300) rpm is what mfg are cautioning about for these, whereas all advice here points to high rpm for bits....

[bleeth]

A Rosette bit is made to be used on a drill press and definitely set at a lower spin speed.
I would not shank one of these up to a spindle and use on the bot.
The Rosette bit will knock them out way quicker, but as Jack pointed out, not as exciting a piece.
I've used very good ones and also cheaper ones (like Grizzly) and they work fine with minimal sanding.
Do them like you peck drill on the mill so your last plunge is just a little material.
The cheaper ones wear quicker due to lower grade carbide tip, but are well worth it unless you are doing many parts.

[jTr]

Dave,
Oh yeah- those cutters are definitely not for the 'bot!!
Think I'll take your advice and go the drill press method- $100 cost for the larger cutter needed (~3.25"), but I can easily see burning that in setup/drafting/testing for a bot run.

Thanks for the input!

Jeff

[bleeth]

You're welcome Jeff.
Helping and getting help on this forum is always enjoyable.
(I learn stuff all the time too!)

[gundog]

I would think you could draw the design in cad and not use the big cutter using a V bit or ball nose to create the shape needed at high speed I don't think the time would be that great.

Mike

[bleeth]

Mike:

Most casing Rosettes are a combination of v cuts and ball nose bottoms as well as rounded over highs and your final cutout.
You would pretty much have to 3-d cut them on a cnc or at least go through multiple bit changes.
For 16 pieces he'll be done on the drill press in 15 minutes.

[carlcnc]

Lest anyone reading this thread gets an "idea"

Rosette cutters are ONLY for drill press

years ago there was a letter in Fine Wood Working magazine about a shop that chucked an insert style one in an overhead pin router,
at 10K rpm one of the knives flew out and speared the operator in the heart ,killing him.

[feinddj]

Or do it the way they have been done since they started making rosettes, with a lathe. With only 16, you could spin them in less than a half day, spend no extra money on cutters and sanding is easy if it's needed at all.