Thread: A couple of Disston #4 type tennon saws nearing completion.

Finally getting back to the saws. Here are some in-process pic's of #12. The saw plate is 13ppi, 0.015" at the tooth line and taper ground to 0.013" at the bottom of the back. I decided to use my bushed saw bolt fit up on this one. The stock is Brazilian cherry. I intended to set this saw up with a stainless back but it seemed too light and tended to chatter so I switched to 1/8" folded brass. Now it's just right and grips the very flexible plate with authority. Much more fitting up to be done of course.

Cutting test #12.jpgRHS #12.jpgSaw bolt detail #12.jpg

Looks good Rob. Great to hear your back into saw making again.

Stewie;

Looks great Rob
One question did you fold the back yourself or were they brought

Hi Rob,

Nice looking saw, and incorporationg some very clever and very innovative ideas, I like the taper ground 15 thou thin plate..

I'm going to do some experiments along those lines and see how it stands up. How have you found the thin plate so far?

Ray

Originally Posted by Simplicity

Looks great Rob
One question did you fold the back yourself or were they brought

I did the back using alloy 260. I think that I want to set it deeper in the handle.

Originally Posted by RayG

Hi Rob,

Nice looking saw, and incorporationg some very clever and very innovative ideas, I like the taper ground 15 thou thin plate..

I'm going to do some experiments along those lines and see how it stands up. How have you found the thin plate so far?

Ray

The thin plates are fine so far, I haven't tried to test one to failure yet. I made the test cuts in wet pressure treated pine using a degree of force I would call aggressive, no problems. I have found however that they stay sharp longer if filed rip with about a 12 degree rake and a very light set. I'm going to try cryogenic hardening on this plate.

My business manager just returned with a bunch of backs, partially completed saws and finished saws that went out for laser marking. Here are some pictures of some of the saws I've previously posted here with markings.


EI camera saw photos 110314 789.jpgEI camera saw photos 110314 790.jpg
EI camera saw photos 110314 791.jpgEI camera saw photos 110314 792.jpg
EI camera saw photos 110314 793.jpgEI camera saw photos 110314 794.jpg

Before I finish this one up I wanted to do some more testing. I clamped up a 2" X 6" scrap of wet treated lumber and cut aggressively down to the back a number of times. Each cut took 4 to 6 strokes.

Here it is all fitted up and ready to test.jpg

Cuts nicely if I do my part and start the kerf straight.

If I do my part it cuts nice straight and deep kerfs with no binding.jpg

And there isn't much tear-out either.

not much tear-out on the back side.jpg

However, I gotta fix this.

Some is okay but this is too much.jpg

I'll split the story here and start a new thread discussing the tensioning of the saw plate. Look here: https://www.woodworkforums.com/f278/tensioning-backsaw-plate-189765 to see the saw tensioning.

Here's #14 (I called it #12 above) just before completion. I have to true up some radii on the transitions, sand a few places and complete the finish application.

No 14 pre completion.jpg

Nice one there Rob
Looks great well done
Matt

Originally Posted by Simplicity

Nice one there Rob
Looks great well done
Matt

Thanks Matt.

The saw making thread seems pretty quiet, everybody on vacation?

Cheers,
Rob

Last night I got to thinking about #14. Specifically about this.


what do these teeth do.jpg


What do those teeth do that are below the cheeks of the handle?

I'm usually squarely in the BOSS (Boring Old Square Saws) camp when it comes to saw design. What can I say, I like traditional designs and design elements. Ask anybody who knows me and they'll tell you I have a strong case of anartismia (artistic deficiency syndrome). For me square corners are easier to understand but nonetheless I'll give the curvy plate profile thing a shot.

First step is to decide how much of the tooth line to remove. Using a machinists square I drew tangents off of the front and bottom of the cheeks like so.

drop a tangent off of the deepest and lowest points of the cheeks.jpg


Note that I set this handle up with bushings on the saw bolts. It adds somewhat to the cost and time but the result is an extremely tight fit up of the saw bolt shanks to the saw plate and handle. Saws I do up this way are so well fitted that even if the saw bolts are loose there is no movement perceptible between the saw plate and the handle. Will it last 100 years? No idea but none of us will be around to complain.


Bushing mounted saw bolts.jpg

Next I pulled off the handle and dropped a line from the bottom tangent of the cheek to the tooth line using a French curve.

Use the French curve to make a transition line.jpg

I think I'll use the curve to the right.

Now to the grinding. Here is the agent of destruction. 60 grit ceramic belt.

Jet belt sander equipped with 60 grit ceramic belt.jpg


Pains me to cut away such a nice square corner.


grinding 1095.jpg

Once the bulk of the steel is gone I moved on to 120 grit aluminum oxide.

slightly more delicate grinding with 120 grit aluminum oxide.jpg


Got it cut back reasonably close to the line.

close enough to start with files.jpg

And on to hand filing.

files.jpg

I refitted the plate to the stock and put in a couple saw bolts to hold it in place. The steel stands a little proud of the cheeks back at the juncture with the lambs-tongue.

stands a little proud.jpg

So very carefully take the area down some.


dress carefull with a three square.jpg

Next I de-burred and dressed the plate. First with a 120 grit 3M DiaPad.


3M hand lappint the ground edge.jpg

These things are great stuff. Cut steel like butter. They recommend lubrication so I use this.

Rust oleum rust inhibitor.jpg

Light oil and prevents rust too.

Follow up with 280 grit Wet & Dry also lubricated with the Rust Oleum product.

Followed by wet dry 280.jpg

Final visual check.


lines up pretty nice, still a little proud.jpg

Looks good, now to brush up the teeth and complete the finishing of the stock. More later.

Here it is fitted up with the handle partially finished.

Handle part finished, plate profiled.jpg

Hi Rob
Can't speak for everyone else.
I know Stewi has been busy in the plane making camp again and there looking great.
But I haven't done a saw for ages due to time and lack of saw plate and backs. And a other million things going on.
Tho yours definitely inspire me to get back to it.
Your post in regard to tensioning the blade made for some interesting reading .
I'm still getting to grips with what your talking about.
Tho that's no fault on your behalf just me.
I've also been keeping an eye out on your rasp making activities big well done there.
If you could send me a dozen when done that would be great and I will review them ,abuse them ,then send that back with a full report of course.
In regard to you hacking a chunk out of the rear of your last creation.
That looks great now hit it with some files on the back lol.
As you know I'm not politically correct.
If it works as intended and your happy .
End of story in my book.
I'm not one to stand in the way of development.
Keep up the good work.
Matt
Ps I'm still thinking about my upside down handle idea.