Sharpening jig for carbide inserts

[Gregory King]

Is there a current jig available in which to mount insert cutters for grinding. We have a General 330-1 HC planer. The local sharpener tells us that he has no hold down jig in which to mount them for grinding. I guess we could fabricate something. So far it has been replace with new, when they get nicked and dull.

[Tony Joyce]

Seems like a waste I know but, most carbide "inserts" are made to be disposable. "Some" can be face ground on a magnetic chuck. Grinding is probably more expensive than replacing. This would not eliminate nicks either.

[Gregory King]

Tony, now that I look at the cutter a bit closer and the cost of replacing, you are probably right. Unless a person had all kinds of time to kill. Even at that, one light touch on each edge is the most you would ever get on any one cutter since they are very small to begin with. Then after reinstalling, I suppose the height adjustment scale would be off marginally. More work than its replacement cost. Oh well, can't blame a guy for trying. Greg

[glenn bradley]

They are designed to be disposable so I doubt there is a commercial solution. Cost vs. time wouldn't work out for me and I'm a hobbyist.

[Peter Kelly]

Carbide dust is pretty toxic. Not something you'd want in the shop anyway.

[Rick Fisher]

Greg..

I have the same planer and recently replaced all my cutters.. both sides worn out .. I bought a bunch from BAM Carbide for $2.75 each plus shipping.

I went to 35 degree instead of the stock 40 because my biggest problem with the stock cutters was chipping, not dullness.

The cutters are basically the same, made by Tigra Carbide in Germany.. Just a whole bunch cheaper ..

[Jeff Duncan]

Also remember that these inserts are made to a very precise dimension. They have to be exact in order to maintain the clean cut and constant height in the cutter head for all 4 sides. I think you would need a somewhat specialized precision grinder dedicated to grinding these inserts, a jig system on an ordinary grinder would not likely cut it. Even if you had a grinder that could handle it, you probably wouldn't get more than 1 grind before the carbide height was changed enough to affect the clearance.

At least that's my best guess;)

good luck,
JeffD

[Gregory King]

Thanks guys for the input. I guess as hobbyists we try to maximize the value of everything. Rick, you made an interesting point in regards to the 35 degree as opposed to the 40 degree angle. I didn't know that there was another angle option. What are the results in the finished product? Might be worth me exploring for our shop. Greg

[Myk Rian]

Save the old cutters. They are worth money in scrap value.

[Peter Aeschliman]

Are the cutters at a skew angle on your cutterhead (i.e., like the byrd cutterheads)? If so, then you'll have a really hard time grinding them properly. In order for them to keep the workpiece flat when they cut, the skewed cutters have a radiused cutting edge. If the cutting edge were flat and arranged in a skewed pattern on the cutterhead, you would get a ridged surface on your workpieces.

I'm with everyone else- these cutter inserts are designed to be disposed of... sharpening will probably cost more than buying new, and even if you did sharpen them, they probably won't be done precisely enough.

[Dan Hintz]

What about if you're sharpening just one or two for turning tools?

[Ronald Blue]

Two points about carbide. One is you would find it has a low magnetic qualities and to consistently grind it requires a diamond grinding wheel. But as was mentioned save the inserts because carbide does have scrap value and it is very dense and adds up quickly.

[Gregory King]

Peter, the cutters are about 1 1/8" long x 1/2" wide sharpened on the two longest edges. There are two small mounting holes [1/8"] in the center. Although very small in size, I still think its possible to grind them with a good jig such as LV would have on a diamond wheel for sure. I'm sort of thinking along the lines of sliding it across the grinding wheel taking only a very small amount. Take some time to initally set-up. I'm only suggesting touching up cutters that are wood dull not ones that are severely nicked. Anyway, I've just been thinking out loud so to speak. Thanks Greg