Honing a flat back and easy honing of a bevel

[matthewwh]

That's a really sweet design, you've got the two things that most manufacturers miss i.e. the guide correctly references off the back of the blade, and the wheelbase is wider than the blade. You also have a single screw so none of the pressure disparity issues you get with two screws and a bar. Nice one!

The only thing I can't see from the photos is whether the pad that makes contact with the blade is ball jointed (like the pad on an F clamp) to cope with tapered blades. Also how do you register for squareness?

The flipping it upside down technique is very similar to the one I recommend with the Kell 3 guide and 10mm plate glass.

I haven't worked out the exact angle but the bars on the top are 11mm so it's not much, and as with your setup you can switch between one face and the other without changing anything.

 

[Steve Elliott]

matthewwh wrote:
The only thing I can't see from the photos is whether the pad that makes contact with the blade is ball jointed (like the pad on an F clamp) to cope with tapered blades. Also how do you register for squareness?

The pad is loose and can accommodate slightly tapered blades but it's not a ball joint. It's held in place by a little clip like the one on the pad of the Veritas Mark I jig.

I get the blade square on the grinder and then the rocking feature of the plate holder allows the entire blade edge to be honed regardless of the exact angle of the blade in the roller jig. This is especially important when honing the back bevel. To keep the bevel narrow the blade would have to be at just the right angle in the roller jig if the plate couldn't rock sideways, but with the rocking feature the entire blade edge hits the plate right from the start.

The way the plate can rock sideways makes this jig unsuitable for very narrow blades. It's meant for plane blades and works very well for that. For chisels you wouldn't want the back bevel anyway.

 

[matthewwh]

Ingenious - you should offer it to Woodcraft or someone - you might not make a fortune but a dollar or two's kickback on each one will supplement the 401K. I'd certainly be happy to stock and recommend it and so far it's only the fourth design I've ever seen that I would say that about.

Switching back to grits for a moment, the scary sharp kits we do run to 5 micron as standard, which is 5 and a bit thousand grit, we do also do sheets going right down to 0.3micron (about 35,000 grit) for those situations where you need the ultimate edge but for day to day stuff 5 is plenty. For waterstones a lot of folks use combination stones 1200/8000 or 1000/6000 which again are fine for everyday sharpening. I wouldn't want anyone reading this thread to think that they needed to go out and buy a 4000 grit stone for day to day stuff because what they have is too fine. As long as it produces a polished secondary with minimal work - it's good.

For chisels I use the same principle but the other side of flat, if the back is concave by a couple of thou it is still plenty flat enough to act as a registration surface but it's enough to let the tip contact the polishing stone first. That way you only need to polish the end of the back rather than the whole thing and if any kind of belly does begin to develop over time you'll see a shiny spot in the middle so you know it's time to work it slightly hollow again.