Hello,
Pretty new to woodworking. I recently built a router table (the John Katz Moses mini router table). I was working on a making some cutting boards out of 1 inch thick solid beech wood (inspired by the recent article in FW magazine) and using a template to get the boards to the same size. I noticed when I was cutting the end grain I kept getting kick back almost instantly, but going with the grain worked smoothly. Does anyone have any suggestions that might have cause this?
here are a few specific about my set up:
I was using a 1/2” x 1-1/4” flush trim bit bottom bearing with a 1/4” shank. I also had a fence to prevent me from taking off too much material probably set back about an 1/8”.
Thanks,
Eric
Replies
Inch thick material and a 1/8" cut is a lot to ask of a 1/4" shank, especially if the bit's flutes are straight.
A better setup would be a 1/2" bit with a 1/2" shank and up-spiral flutes taking a much lighter cut. Back up the end grain to reduce blowout exiting the cut or even better cut the end grain before the long grain so you'll remove the inevitable blowout even when backed up.
1" x 1/8" of end grain beach is a good amount of material to take off at once. There certainly could be other factors. Taking off less material might fix this. Other than flush bearing bits following a template you could use a spiral bit and a template insert. This allows you to adjust the depth of cut in addition to a fence adjustment.
My favorite trim bit, did a lot of template work with it, the 5/8 dia allows for plenty of cutter speed an 20,000 rpm, the 1/2 shank is rigid and dual bearings allows to Flip the template to follow grain direction minimisant test-out : https://www.leevalley.com/en-ca/shop/tools/power-tool-accessories/router-bits/51851-double-bearing-flush-trimming-template-bits?srsltid=AfmBOoptAdP0W1Pd7FdaDjPovDuiZJC1NdyONsSCOq3JxMD1Ysks9xiJ
Too greedy a cut.
Thanks guys for your comments. Super helpful! I was using a straight bit, so moving to spiral and reducing the cut depth makes sense to me.
Do you guys have a rule of thumb for max cut size using a 1/4” shank? Also is end grain typically more sensitive? It kind of makes sense if I think about it in therms of whittling… cutting with grain vs cutting perpendicular to grain (perpendicular requires more effort which is why my router was struggling).
End grain is harder to cut with a router and more likely to burn. You need a light enough cut matched with a fast enough feed rate to get a clean cut. Long skinny bits will chatter and even break off when pushed too far.