Jointer knife jig sharpening angles

pennview · Post by **pennview** » Mon Sep 05, 2011 12:45 pm

If you watch the video on the website, the inventor of that jig shows you the steps for sharpening three blades equally. It's all in the sequence of how you swap out the blades when going to the finer grits.

Like I said, the whole thing is really slick, takes minimal material off of the blades, and making a home-made version should be quick and easy. The inventor says you can even sharpen throw away blades three to five times before then need to be discarded. That is, unless you put a big nick in them; then they're scrap.

michaeltoc · Post by **michaeltoc** » Mon Sep 05, 2011 12:56 pm

I just made some measurements: the conical disc is at 3.2 degrees, and the sharpening jig is about 3 degrees (difficult to get an accurate measurement on the jig).

pennview · Post by **pennview** » Mon Sep 05, 2011 1:13 pm

One other point on using the conical disk is that you're really grinding the knives, not honing them, and if you're not careful you can remove more material than necessary. I have the Shopsmith system and used it once and while it works, I think it's best for repairing nicks or otherwise damaged knives.

On the other hand, the Makita grinder does about as good a job as anything out there short of a professional set-up. In fact, you probably could use one of these in a professional shop. It really hones the blades, using a water bath, so you remove very little metal and it will allow you to touch up disposable blades that aren't damaged. Makita has a separate coarse wheel for taking out nicks. The problems is that it's not all that cheap, but then again Shopsmith planer blades aren't cheap either. The Makita will sharpen up to 15" blades. Don't know why it stops there since they used to make a 16" planer.

All that said, for next to nothing, making a copy of the Duelen jig looks like an economical and easy way to sharpen knives or touching them up. I'll be making one.

JPG · Post by **JPG** » Mon Sep 05, 2011 1:39 pm

pennview wrote: . . .
All that said, for next to nothing, making a copy of the Duelen jig looks like an economical and easy way to sharpen knives or touching them up. I'll be making one.

Any suggestions regarding the inclusion of the wheels on the back side?

pennview · Post by **pennview** » Mon Sep 05, 2011 3:49 pm

JPG, I don't see any wheels on that jig, but perhaps that because of the low resolution of the video. In any event, I don't know what role wheels would play in something like this since you're sliding the knives back and forth on sandpaper. The jig would be rock solid with two knives alone. I guess I'll find out after I make one.

JPG · Post by **JPG** » Mon Sep 05, 2011 6:32 pm

pennview wrote:JPG, I don't see any wheels on that jig, but perhaps that because of the low resolution of the video. In any event, I don't know what role wheels would play in something like this since you're sliding the knives back and forth on sandpaper. The jig would be rock solid with two knives alone. I guess I'll find out after I make one.

A knife on each side! That detail escaped me the first time!:eek:

His 'three knife' procedure is an approximation to 'equal' honing. Probably close enough for one sequence. I would rotate the 'odd blade' each subsequent time. Actually I think the 'balance' concern is over blown when 'honing'.