Melamine

[john_l]

I just tried a 1/4" compression bit (Onsr 63-110) to cut the melamine for 2 sided finished parts on the counters we build. I am cutting 3/4" 2sided melamine in 2 passes with our PRT. I was carefull to toolpath as to get both the up and down edges cutting on the first pass to avoid chipout on the top edge.

Problem is I still get the chipped edges on topside.

Previous to this, I used either an up or down spiral and just put the less visible edge as the more vulnerable for chipout.

Machine is very tight. Tried slowing and speeding feed rate to no avail. Slow as 2ips fast as 4ips.

[thewoodcrafter]

I have a old book but the 63 series bits seem to be for aluminum. I can't find 63-110 bit.

Anyway I use a mortising compression bit. Are you sure your first pass is deep enough?

I use R & B Tool Supply bits, no problems.

[john_l]

Sorry Roger, It is a 60-110 bit. I did lower the bit a little more for the first pass and it seems to have helped a lot. So you were correct, and thanks.

[dlcw]

Like Roger says, on the first pass you need to plunge deep enough so that the upcut part of the bit is below the edge of the melamine. You want the downcut part of the bit cutting the top layer of material and then when you punch through the bottom layer, you want the upcut portion of the bit cutting the material. Same principles apply to cutting veneered plywood.

Don
www.dlwoodworks.com (http://www.dlwoodworks.com)

[garyb]

I'm guessing you meant 60-110 that being the case your feed rate is too high that cutter is designed for a low fee rate.
Try the 60-112 (60-100DE series) designed for high feed rates
As Roger asked is your first pass deep enough?
those cutters have a .531 upcut flute length

[john_l]

Thanks guys. Yes, apparently I was cutting too shallow with the first pass. I had both cutting edges into the meat but I guess the down cutting part wasnt as effective with the shallow pass. I went down to .6" depth first pass and have found 2.4 ips to throw nice chips. This is the flakeboard brand melamine too, IMO they have cheapened their product considerably in the last couple years.

Anyway, cutting good now, thanks!