Hi all,
I have been using a 3/8 bit to make finger joints in hickory. I know this is tough stuff.
I am using a jessem router table and 3 1/4 hp porter cable router at 22,000 rpm.
My router bits seem to get pretty dull and stop performing in no time. To be specific, I cut 40 fingers in 1/2 inch material. I Changed the bit and cut just 28 more and think if I had a third 3/8 bit I would be changing it now.
All my bits are high quality, ie the big names. Freud, Whiteside, Amana. Of the two mentioned above, one was new the other just returned from being sharpened.
Is this typical for hickory? Any comments would be welcome.
Replies
I haven't worked much in Hickory but I have used some Pecan, which is also extremely hard. I didn't notice problems when routing dovetails but I didn't do that many. I noticed it dulled up my planer blades extremely fast but dulling a router bit in 40 1/2" cuts seems fast to me. I have notice when routing pecan it does burn bad, I attribute this to the hardness of the wood more than just dull bits. Is the hickory burning or is it really hard to push the bit through after a while?
Well, I noticed two things, both taught to me by me dad.
First, it becomes very difficult to push the stock through and second the nice long chips the bit use to take are now just fine dust.
The lack of performance is directly reflected in the waste.
Jim
Definitely sounds like a dull bit but that still seems like it is dulling fast to me. I realize Hickory is very hard, but unless it has some silica imbedded into it the bits should be lasting longer. Have no solution for you excpet to try to sharpen them more often if possible.
Easy answer, if you're taking single pass, full depth cuts.
Suspect you're cutting at least 1/2" deep? There is no cutter that can stand a tunnel cut 3/8" x 1/2" for very long. I'm surprised you got that much life out of them/it. There is some material sensitivity to wear, but full thickness, or deep tunnel cuts are far more detrimental.
Dovetail & box joint making jigs put the router bit in its most severe service, nuthin's tougher. Preplow the ways in stages; use a plunger or stack spacers. Waste the dovetail sockets first with a smaller dovetail bit. You'll add substantial life to the finish-cutters this way.
Routers & bits have been pushed way beyond their practical limits with these jigs.
More on cutters.
Hickory is a tough species but it's more the way you are cutting the fingers than the material. Pushing straight on to a bit will dull it quickly. I'm not the biggest fan of box joints but when I have to cut them, I use a dado head on the saw. A couple of options are the bits listed below. Other companies carry similar patterns.
If you remove waste first, the bits will grab and may pull the work piece, not a great process. Freud and others make saw blades specifically for box joints. A straight bit with skewed carbide will last longer than one with straight cutters.
http://www.woodsmithstore.com/271405.html
http://www.right-tool.com/romcardc38do3.html
Beat it to fit / Paint it to match
I prefer using the Freud Box Joint saw blade on my table saw. Great blades, the set will do 1/4" and 3/8" box joints.
Work Safe, Count to 10 when your done for the day !!
Bruce S.
Check the recommended RPM for the bit. That may tell the tale.
Regards,
Sean
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