Routing Laminated Strand Lumber Material
LSL material can be very tough on CNC router bits. But solid carbide reputedly holds up well. April 21, 2008
Question
We have some machining to do on 1-5/8" thick Timberstrand LSL board. I have found it extremely tough on tooling. Is it because of the high resin content or did I just hit some junk in the board? I was cutting in 3 passes with a 3/4" diameter brazed carbide tool and it was chewed up halfway through the pattern. Part movement is not an issue - the 4 x 12 sheets I was cutting on our flat table router weigh in at about 250 lbs. I'm hesitant to switch to solid carbide if the board has a lot of junk in it. Any suggestions would be appreciated.
Forum Responses
(CNC Forum)
From contributor A:
Use a solid carbide spiral and you should have no problem with LSL. The cores on our doors are LSL and I machine them all day long and have never had a tool issue. Brazed tools just don't cut it on a CNC for me. When I do light cutouts I cut 1.80" in one pass with a 3/4" compression endmill with no problem.
From contributor B:
Use a Solid Carbide tool and you will be happy with the results. Depending on the edge finish a compression for a great edge finish, or a ruffer if you do not need a good edge finish.
From the original questioner:
Thanks for the response. What would you recommend for feed and rpm with a 3/4" compression spiral?
From contributor A:
When I do the light cutouts I usually run at 18000 rpm and 8m/min on a 3/4" compression 1.80" thick in 1 pass. The LSL does have 2 layers of MDO and 1/16" wood veneer so I keep my feed speeds down because I'm more worried about chipping and breakout than I am about speed.
From contributor B:
Contributor A mentions 8mpm (316IPM) @ 18K. We suggest 15K at those feed speeds. Our tool has a .700 to allow for chips to clear.
From the original questioner:
To contributor A: Just curious, are you cutting on a pod and rail or flat table? To contributor B: What is a .700?
From contributor B:
This tool has a 2 flute up shear and 2 flute down shear. The up shear portion is .700. This gives the bottom a perfect edge finish and the down shear gives a perfect finish on the top.
From contributor A:
We are using a Biesse Rover 24 and a Rover B, both machines are pod and rail and are mostly used for entry door hardware preps and custom arch doors and transoms.
