Dull router bits?

[gwyneth]

I've got a lot of straight router bits, some of which have gotten pretty heavy use in the last year.

Tonight I noticed that the oversized 3/4" one was having a terrible time in the router table on ash--even with less than 1/4" height/cut.

I know bits get dull eventually, and I'm wondering about how many feet/yards/miles other people get out of them.

And does anybody sharpen them? Shop Notes described how a few years ago, and I have a lot of diamond files and hones.

Thanks for any input.

(Just now, three hours after power-tool curfew it occured to me that I could see what one of the never-used straight bits--of course, in some weird size--does with the ash to see if dullness of tool or worker is the problem.)

[Slik Geek]

And does anybody sharpen them? Shop Notes described how a few years ago, and I have a lot of diamond files and hones.

Couldn't tell you how much "mileage" I'm getting, but if they have "gotten pretty heavy use in the last year", they are probably getting dull.

First be sure they are clean.

You can see "dullness" by looking at the cutting edge in bright light. Compare the upper edge (closest to the shank), which hasn't seen much, if any duty, to the bottom edge, which has seen the most duty. Look for a reflection from the edge (cutting tip). (A 10X or 20X magnifier helps).

I've had reasonable success with diamond hones reconditioning carbide router bits. Just be sure to NOT hone the outer edge - the one that determines the diameter. Hone the flat that meets the outer, curved edge. Your finger should be able to feel the difference in sharpness after honing.

[Uncle Cracker]

All my bits are dull... I watch them and watch them, but they just sit there...

Seriously, you can feel a dull bit with a fingertip. I have tuned some of mine up with a diamond hone, with mixed results. Straight-edged bits do pretty well, but you need to try to hone the entire edge at once, or you'll have a tough time getting it right. Profile bits, on the other hand, are a PITA to hone, and I just replace them.

[LarryG]

I know bits get dull eventually, and I'm wondering about how many feet/yards/miles other people get out of them.

I find that an average of about 250 linear feet is the absolute max if a pristine cut is required. Of course there are lots of variables ... wood species and density, the type of cut, the bit profile, feed rate, etc.

[cgallery]

I have medium and fine diamond hones (credit-card sized) from DMT. I have used them to keep my router bits plenty sharp.

The profile bits aren't any more difficult for me than straight (because I'm doing the flat surface). The problem bits are small ones (like a slot cutting bit) where the carbide may be only 1/4" high. In these cases the carbide surface isn't large enough to guarantee that you'll be able to keep it flat (relative to the stone).

In those cases I usually have to use a board or something to keep everything in alignment.

But it works and I just bought some new carbide bits that were on clearance (Porter Cable) because they were just so darn inexpensive. The Porter Cable bits are good quality. But I found my old bits, which have been honed numerous times, may be just a tad sharper than the new bits!

[LCHIEN]

I've got a lot of straight router bits, some of which have gotten pretty heavy use in the last year.

Tonight I noticed that the oversized 3/4" one was having a terrible time in the router table on ash--even with less than 1/4" height/cut.

I know bits get dull eventually, and I'm wondering about how many feet/yards/miles other people get out of them.

And does anybody sharpen them? Shop Notes described how a few years ago, and I have a lot of diamond files and hones.

Thanks for any input.

(Just now, three hours after power-tool curfew it occured to me that I could see what one of the never-used straight bits--of course, in some weird size--does with the ash to see if dullness of tool or worker is the problem.)

I recall in the FWW carbide straight router bit shootout they published a few years back
that router bit life was measured in terms of tens of feet to maybe a hundred or more linear feet. That's when the cut got rough and chipouts started to occur in their melamine laminated particle board. I would imagine that particle board is maybe 2 or more times worse than hardwoods (but more consistent for their tests) in terms of abrasive wear.

Page 12 of the Nov 2007 Wood magazine describes how to sharpen router bits using a diamond hone.

[Jeffrey Schronce]

I recall in the FWW carbide straight router bit shootout they published a few years back
that router bit life was measured in terms of tens of feet to maybe a hundred or more linear feet. That's when the cut got rough and chipouts started to occur in their melamine laminated particle board. I would imagine that particle board is maybe 2 or more times worse than hardwoods (but more consistent for their tests) in terms of abrasive wear.

Page 12 of the Nov 2007 Wood magazine describes how to sharpen router bits using a diamond hone.

You are exactly correct. FWW has done two reviews, one of straight bits and one of ogee style bits. In both tests they did their hardwood cuts in maple and cherry first, then abused the bits with MDF. They stated MDF put 2 - 3 x dulling per linear foot on the bit than hardwood.

So, it depends on what you started with (Whiteside or ebay bit?), what you have been cutting (clean poplar or MDF?), how often the bit has been cleaned, etc.

But if you state you have used the heck out of them, then yes they are probably dull. Ridge Carbid does sharpening for around $4 per bit. Of course I would think that could impact the overall cut size of a straight bit, though I could be wrong.

[Holbren]

[quote=Slik Geek;303838]Just be sure to NOT hone the outer edge[quote]

Just wanted to reiterate that point.

[gwyneth]

Well, Brian had the real solution. I just ordered a couple of Whiteside bits from Holbren.

[Jeffrey Schronce]

Well, Brian had the real solution. I just ordered a couple of Whiteside bits from Holbren.

You can't go wrong with either Brian or Whiteside! I happened to be placing an order today with another vendor and a few Whiteside bits fell into my cart! Seems to happen . . .

They are great bits. At this point you will know that you are starting with a superior bit!

[gwyneth]

You can't go wrong with either Brian or Whiteside! I happened to be placing an order today with another vendor and a few Whiteside bits fell into my cart! Seems to happen . . .

With the BT discount, they ended up being less expensive than the Freud equivalent at Amazon, even with the 10% Freud discount, and that phony 4-for-3 deal.