Getting A Straight Edge On A Chisel

[Sgian Dubh]

Apologies if this topic has been covered several times before.

I've had a good rummage around with the search engine looking for a thread dedicated to getting a straight edge on a chisel. If there is a go to thread for this topic I'd be grateful for a link to it.

The first chisel I sharpened turned out perfectly and I was really happy about it. The second one was the merest whisker off perfectly straight. Not a big deal, but enough for the perfectionist in me in to think "I wonder why that happened?" The third was less straight again, enough to frustrate me and mumble a few quiet sweary words under my breath. The fourth was perfect. On one hand I was really happy, but also confused as I'd applied the same exacting criteria to all four chisels.

Where am I going wrong?

Stone trued. Really careful how I clamp the chisel in the jig. Really careful about the universal support being straight. Thinking about the geometry of everything involved, ticking off a full checklist and expecting a perfectly straight edge every time, but not quite getting it.

Thanks in advance for any help.

[Ken S]

You seem to be doing most things right. My suggestion would be to use your black marker on your bevel. Turn yourTormek on momentarily, just long enough to remove a little marker. Stop and check with a small square to verify that your new grinding is square. Too many people grind too much before checking.

My other suggestion is to try adjusting your finger pressure to help "steer" your grinding.

Keep trying and do not lose heart.

Ken

[Sgian Dubh]

Thanks Ken.

I do use a marker pen for most sharpenings, it's such a simple and effective method.

I need to get a small square and I'm grateful for your suggestion about finger pressure and steering.

Aye, I'll keep trying and no doubt get to the bottom of it with a bit more experience.

[jobewan]

Hey Sgian,

One more thing beside the good auggestions by Ken.  Check the alignment of the jig - those two smaller knobs on the SG-77 are a bit touchy.  There is a line on the side of the jig to aid in making sure the jig is straight.  Also - on every chisel and plane blade I am sharpening I check the alignment of the tool to the jig with a small engineers square.  When I first started sharpening with the Tormek I had exactly the problem  you are describing, and it was driving me nuts.  The slightest misalignment of the tool in the jig will create a problem. 

I hope you get this "straightened out"!   

Joe

[Sgian Dubh]

Thanks Joe, much appreciated.

[Ken S]

Good thoughts, Joe.

Ken

[Ken S]

Over the years, I have acquired three generations of square edge jigs. Tormek promotes the SE-77, the latest model, primarily for being able to correct squareness with chisels. I realize that there are many more chisel sharpeners than plane blade sharpeners sophisticated enough to expect controlled camber grinding. This is unfortunate. In my opinion, the camber control is where the SE-77 really shines.

Yes, the SE-77 can be adjusted to correct squareness. However, if the two knobs are not correctly set, this same "feature" can also cause being out of square. Check early and often with the smallest engineer's square you can find. Incidentally, Brian Pratt (Boothill Customs) makes a pair of very nice, practical squares. They are small, accurate, and made of plastic, which makes them both inexpensive and impervious to water.

When Tormek introduces a new jig, they discontinue the older model. I happen to prefer the SE-76, the older model, for sharpening chisels. It is not adjustable like the SE-77. There are no knobs to go out of alignment. By all means, keep your SE-77. However, I recommend also looking for a reasonably priced SE-76 if you sharpen a lot of chisels.

Ken

[Ukfraser]

Also - on every chisel and plane blade I am sharpening I check the alignment of the tool to the jig with a small engineers square.
Joe

A couple of questions as usual.
I have noticed a couple of my chisels as not square to the jig when up against the end stop so
Do you square them at the end stop end
Or do you move them to where the centering line is and square them there (as they do in the one hour video  on plane blades when they want to introduce a curve)?

I have tried both and results are better than with the chisel not seated square but with the centering method, the end stop no longer stops the chisel falling of the stone so i have to be mega careful.

Random question, there appear to be two lines proud. One is obviously for centering the plane blade But what is the other one for? Or is it just a casting mark. I cant see any reference to It in the instructions!

Thanks