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View Full Version : Need Help! Cutting 3/4" OSB



john@tlt
06-04-2014, 11:23 AM
I have a CNC router with a 60x96 table. It has limited vac holes and two 5HP pumps. I purchased a bundle of about fifty five sheets of 3/4" OSB to run on this to make a 16x16.5 chair seat with a simple inner cutout, nothing fancy. The table had to be gasketed off plus the spoilboard was gasketed and given breathing holes to suck the parts down in individual pieces. I am using a 3/8 2 Flute spiral Down cut on the OSB due to limited space between nested parts which worked fine on particle board of the same thickness. Sadly now that I have changed to OSB I cannot get the material to hold to the table. It like almost all material you buy in bulk is slightly warped on each end. After two days of working with a couple sheets they stuck but not well. What feeds and speeds as well as cut depths would you recommend. The spindle has no thrust bearings so we try and ramp in on all cuts if that is any help. Thanks!

ger21
06-04-2014, 11:37 AM
How big is your spindle?

john@tlt
06-04-2014, 12:25 PM
380 V, 28 Amps, 16HP, 11.8kW, Max RPM 18,000, 300Hz.

ger21
06-04-2014, 12:52 PM
I'd try somewhere around 500ipm at 16,000 rpm. You might be able to go up to 700ipm.

john@tlt
06-04-2014, 01:34 PM
Go max depth or passes? The spoil board isn't sealing which I am assuming is partially due to slightly warped ends and the material breathing a bit.

ger21
06-04-2014, 03:22 PM
I guess it depends on how well it's holding down. cutting forces will be pretty high at full depth. I'd probably prefer an upcut or compression for a full depth pass, but the downcut should help hold it down.

john@tlt
06-04-2014, 04:00 PM
The downcut has helped a lot for hold but the amount of cleanup doubles almost matches the program run time. I have checked with Accu-Router, the company that reconditioned/widened our table, it apparently has such limited vacuum line volume that the option of installing our 10hp vac to the table would be somewhat a waste of time. I have sealed a board to try out in the morning and have regasketed the bottom table to see if it may help, hopefully the fifth time is the charm. Our neighboring company has the same accu-router table setup but is getting about 36 psi on an estimated 6hp vac which makes me wonder there might be a leak that we are just not finding. I appreciate your help!