a diminished difficulty

[Ken S]

I have noticed a decline in the number of problems with chisels being ground out of square over the years. While I like to think this is because of more careful technique, I also believe improvements in jig and accessory design play a part.

The newer truing tool, the TT-50, makes accurate truing of the grinding wheel much easier. I have encountered numerous puzzling problems caused by an out of true grinding wheel.

The redesign of the square edge to the SE-76 was a major improvement. The registration surface was changed to the broader face of a bevel chisel. A right angle surface was introduced to help keep the chisel or plane blade square.

While the SE-76 was a giant leap forward, there was still room to grow. Robin posted an idea for tweaking machining of the front reference edge. The distance between the two clamps was still not ideal for narrower tools. We were getting closer.

The newly introduced SE-77 has not yet been available to make a major dent. I believe it will. It is machined out of zinc. This should clean up the problems Robin noted. It features adjustable, controlled angle adjustment to insure square grinding. This is very useful, especially with tools which are not manufactured parallel. It finally answers my long time wish for camber control for plane blades.

I think the real improvement in edge squareness will be due to the redesigned clamps. One side, the side with the ninety degree registration fence, is still fixed. The clamp on the other side moves in and out. It can be moved in much closer to a narrow blade. That places the clamping force closer to the blade.

I do not believe we have seen the last of the out of square posts. A narrow chisel is still a difficult too to accurately sharpen. I do believe that improvements in the truing tool and square edge jig, when combined with watchful technique, will minimize these problems.

Ken

[Dakotapix]

Watching the Tormek video on using the SE-76 jig (available on the home page) was a great eye-opener for me, Ken. The key here was the phrase "First adjust for the thickness" by lightly tightening the left hand knob on the tool, then moving it over to the right hand stop and tightening that knob. In the video there was no further tightening of the left hand knob. Further tightening on the left knob is what I believe to be the cause of out of square edges, particularly on narrow blades. Knowing this has worked very well for me.

[Ken S]

Good point, Dakotapix. As Yogi Bara said, "You can see a lot of things by looking." Good find.

Ken

[Hatchcanyon]

Further tightening on the left knob is what I believe to be the cause of out of square edges, particularly on narrow blades. Knowing this has worked very well for me.

That depends!

I have worked a lot of chisel and plane irons with the SE-76. Sometimes the first approach did not show a very good result. For example grinding was "faster" on one side than on the other one. One could countersteer this behaviour by tightening or loosening only the left knob. Obviously the iron was tilt a bit.

With the new SE-77 these settings are more sophsticated and controllable. I like the new tool and use it now regularly.

Rolf

[Dakotapix]

I'm looking for a USA source of the SE-77 jig now. Anyone know of one? I just picked up an old Stanley no. 5 that I want to convert for scrub use and will want to add a camber to the edge.

Well...never mind. I just ordered one from Highland Woodworking. Listed as a pre-order available in July 2016.  I noticed some on eBay as well but decided to go with a known retailer.

Really looking forward to this jig.

[Ken S]

Using the jig setting A on the TTS-100, which gave a reasonably long protrusion, I was able to easily add about 1/16" camber on a two inch blade. I think that is 1.5mm camber on a 50mm blade, the width designed for the number four smoothing plane and the number five jack plane. (the two most common sizes).

That should give you a good, but not overly aggressive roughing blade. If you would prefer a bit more camber, try more blade protrusion.

I used the TTS-100 for a known, repeatable Distance. I set the protrusion using the Anglemaster. (That is generally considered backward......)

Please post your thoughts on the new jig.

I believe success is a combination of the efficiency of the jig and the skill of the operator. The jigs keep getting better. If we can keep improving the operator's skill, we are approaching the best of all possible worlds.

Ken