Through cutting laminated (2S) stock

[nat_wheatley]

I've started to cut a number of parts that I need to cut from 11/16" flake, laid up on both sides with vertical laminate. I'm using a 1/4" compression bit, cutting at 4ips, using a climb cut for the first pass, cutting almost full depth, then a conventional cut for the final pass.

Several things are happening. I'm getting some chipping on the top side of the parts. It seems to be happening on the first pass, the second pass actually cleans it up a little.

I'm getting a little bit of 'fuzz' on the edges of the cuts on the bottom side of the parts. This isn't a huge issues as the buffing station on my edgebander seems to be cleaning it off.

Lastly, my cut quality isn't all that great. It's a little rougher than I'd like. I'm having to increase my glue line at the bander to get full coverage.

Any help/suggestions would be great.

[jhicks]

Nat, is it safe to assume you are cutting past the 1st level of the compression bit cutting edge transition? Some have 1/4" depth before reversing, others have more but in either case one needs to get deep enough to clear the transition between up and down cut edge.
If you are then you should not be getting this condition but you shouldnt need to reverse directions either. Take a look at the scrap edge. Is it clean on 1st and/or 2nd pass? If yes,That edge would be what I would think you want. I cut completely in conventional. Maybe that's why you're getting it cleaned up on the 2nd pass.
Since the compression bit is handling the up and down cut simultaneously, no need to reverse directions.

I also recomend a simple, cheap($20.00), straight carbide 2 flute 5mm cutter for melamine and veneer ply. Cuts very clean and also drills 5mm holes with no bit change. Yep I run 3 passes but since its one bit to drill, dado, and cut out, Im not overly concerned about speed as long as results are good.
Good luck

[Gary Campbell]

Nat...
Have you tried 1,2 and 3 ips for reference? I would toolpath some squares at 2 ips and then use the keyboard to increase/decrease on each side to see if there is a difference.

Laminate may require slower speeds than wood veneer that I usually cut. Also try another brand of bit, some brands just work better than others on certain materials. Good Luck!
Gary

[nat_wheatley]

Looking back over it, I think it's safe to say that the first pass is too aggressive for this material. I'll try cutting back on my cutting speed and decreasing pass depth and see if I can dial in the cut quality/ chip issue some.

The climb/convential cut does work well to compensate for the flex of an agressive first pass, but I may be able to do all climb cutting throughout if I'm taking less off per pass. It does seem as though the climb cut is causing the chipping.

I'll play around with different bits as well. I am interested to see what a straight bit will do for me.

Thanks for the input.

[nat_wheatley]

This stuff is killing my bits!

Material is 19mm thick, cut speed 4ips, first pass: climb/9.25mm, second pass: climb 18.5mm, final pass conventional 19.5mm.

I had a number of small chips in a new bit after cutting just 5 sheets today. The bit was a 1/4" downspiral (Onsrud?) and was the only bit I had on hand that I could sacrifice.

Will slowing down the cut speed help?

[coach]

Nat, If you call onsrud and ask for tech support they will give you great advice. I use what was reccommended to me and I make hundreds of cuts in 3/4" laminated particle board (standard thickness laminate)I just happen to have the number in speed dial.
800 234 1560 or 847 362 1560
David

[nat_wheatley]

Thanks David, I'll give them a call.

Nat