Snipe hunting with a Tormek

[Josh Bowman]

Anyone have a Tormek T-7 and the Planer knife jig? Have you used it on 12" planer blades? Settiing my Tormek and jig up per the instructions, I am getting a "snipe" on the last 1 inch of the blade. This is the side that goes beyond the Tormeks grinding wheel. Everthing seems tight, but it doesn't make since why it tries to grind extra at that point. If you set the edge of the blade against a flat surface like a table saw table, you'll see the blades bevel rises off the flat surface by a fair bit. The back side of the blade is dead flat. So I tried the other blade and got the same results. Anybody run into this?

[John Coloccia]

When you're sharpening on the Tormek, it's pretty important to keep 100% of the wheel covered by the blade if the blade is longer than the wheel. If you let the blade move over to the point that only 50% of the blade's in contact with the wheel, for example, the same amount of pressure on less steel will remove material from that end just that much faster, leaving you a curved surface.

In fact, this is exactly how you radius a plane iron with stones...you simply lean on one side, and then the other, instead of using even pressure.

[Josh Bowman]

Did not think about that. But why is it more aggressive on that side. I think I let both sides travel past the edge of the wheel. Maybe I favor one side. I will have to find some more blades to expeiment on, keeping them fully on the wheel.

[John Coloccia]

I'll just mention that even when I get them straight, they're still not really all that straight. I found it's very difficult to sharpen jointer/planer knives on the Tormek. I have to keep checking the blade for straightness, and apply more pressure at just the right point, etc. IMHO, sending them out for sharpening is money well spent.

[Jeff Farris]

It kinda sounds like you guys may not be getting your depth of cut set correctly at the outset.

You should tweak the bevel angle and height adjustment thumb wheels until the blade is just touching the grindstone. At this point, make sure that the blade holder is not lifted off the support beam. Make sure the blade is parallel to the grindstone and that the bevel is flat (or reasonably so) on the grindstone. This is your zero point. From there, with the locking knobs tightened, turn both of the height adjustment thumb wheels up by an equal amount. One half turn would be about the largest adjustment I would make at once. After raising the thumb wheels, unlock the locking knobs and let the unit settle down onto the height adjustment thumb wheels and re-lock the locking knobs.

If you press downward on both the support beam and the blade holder, there should be a tiny gap between them at the front edge. Once you grind enough off the blade to eliminate that gap, your blade should be straight. Any irregularity in the edge would indicate that the blade is floating on the grindstone (like a chisel or plane iron does) and that the support beam is not providing the limit for the cut that it is designed for.

[Jeff Farris]

Just want to add a comment regarding John's post.

While he is right about pressure on one side or the other influencing the grind, if you set the Planer Blade Attachment up correctly, and grind until the support beam is fully supporting the blade holder, it will not matter how much of the stone you use or how much pressure you put on one side or the other. Unlike all the other jigs in the system, the support beam provides a limit to the cut.

[John Coloccia]

Honestly, I think I just push too hard and let it flex. It's a mental block, I think, just like taking a golf swing. "This time I'll just tap it onto the fairway." LOL. Not!

How straight can you get yours? I struggle doing better than .01".

[Jeff Farris]

To be honest, I've not measured them other than eyeball against a reference table. If I can't see a gap, I'm calling it good.

[quang nguyen]

Anyone have a Tormek T-7 and the Planer knife jig? Have you used it on 12" planer blades? Settiing my Tormek and jig up per the instructions, I am getting a "snipe" on the last 1 inch of the blade. This is the side that goes beyond the Tormeks grinding wheel. Everthing seems tight, but it doesn't make since why it tries to grind extra at that point. If you set the edge of the blade against a flat surface like a table saw table, you'll see the blades bevel rises off the flat surface by a fair bit. The back side of the blade is dead flat. So I tried the other blade and got the same results. Anybody run into this?

Last time I ask Tormek help desk, they recommend me to register and join this group for info exchange.
http://www.tormek.com/forum/index.php (http://www.tormek.com/forum/index.php).

I also got lots of helps from Tomek rep below:

Håkan Persson <hakan@tormek.se>