MDF &13 PLY BIT LIFE ?

[jhicks]

We have ramped up on a project that has 3/4" MDF veneer with cut outs, drilled holes and area clears in 4" squares .875" deep, as well as drill and cut outs of 13 ply birch. I guess we're going though more sheet stock than I realized and have experienced some stalling even with cut depths at .375 with 2 passes to cut out the shapes.
we're running at 140 to 160IPM at 15,000 to 16000 rpm on a 5HP spindle and PRT w/ascension controls/G code tool path.
We have used both compression and 2 flute onsrud 3/8" diameter bits for these 2 operations trying to extend compression as long as possible for cut out edges.
My question is what are you guys used to as far as bit life before replacing or sharpening?
I guess we've gone through 10 to 15 sheets of each and this end mill is shot with the compression also struggling.
Any guidelines or experience with volume and preventative sharpening or replacements are appreciated.
Thanks

[elcruisr]

13 ply birch has been pretty tough on tooling in my experience. Lots of glue to cut with all those layers and glue is pretty abrasive stuff. Last batch of russian birch I cut had a tool life of around 15 sheets cutting the same tool, feeds and speeds as I use on MDF.

The MDF I cut with and Onsrud 3/8" single flute compression. 16,000 to 18,000 rpm, .75" per pass and a feed speed of 480 IPM or if you prefer 8 IPS. In MDF I could probably run 40 sheets before it got very dull, maybe more.

[hines]

Jerry, haven't had my bot long enough to have a good average on bit life. You may have heard/seen this before, but I do know that according to the chip load calculator your numbers are slow, which will cause over heating and shorter life on your bit. For a 2 flute cutter in MDF, you should run around at least 360 ipm at 12000 rpm. Faster Rpm's would require faster ipm speeds. Best thing to do is run some same cuts with about 10 different 36-48 inch lines. Change the IPM and RPM on each line and see where that gets you. I see that you've been on the board a while so this may be old hat for you, in that case ignore this post.