Thread: Making a few hand saws

Originally Posted by M Williams

I meant to ask before but how are you guys cutting your saw plate?

My current way involves a cutoff wheel and sparks lol.

Yep, I think that's the way most of us amateurs have figured out.

Clamp a couple of bits of 1/4" thick bar along the cut line to act as a guide & heat-sink. Cutting thin plate (20-25 thou) is very easy. If you use a fine wheel (1mm over here, so whatever the equivalent is in countries that are still using duodecimal units of measure ), and move it through he cut smartly, you'll generate very little heat either side of he cut. Little dags of metal, especially at the ends of the cut, sometimes get red hot & cool rapidly enough to harden, so I always "joint" a fresh edge with a file that's nearing the end of its working life. You can easily feel any very hard spots, so just take a few more swipes until the resistance feels nice & even all along the edge. Guillotine-cut edges are often hard right along the edge, but it's only a couple of thou thick at the most, so again, a few swipes of a file gets you through it.

Cheers,

I have made a number of folded backs using 25mm by 2 or 3mm thick brass angle as the starting material.
The angle requires annealing before and several times during the folding process or it will crack, especially if a hammer is used for flattening.
Usually the first ~60% of the fold can be done safely before it needs re annealing, the remainder of the fold can be done in one go, but if to be sure I annealed mine again after about 95% of the fold was complete
On some backs I used a press to progressively fold the angle, stepping back and forth along the angle until there was minimal gap.
The slot comes out at about 22mm deep and the last fold after the 3rd annealing work hardens it enough to make the back quite springy so it gripped the blade wherever it was put.

On one back I had it folded about 95%, did the 3rd anneal and then used a lumpy to finish off and this made it even springier - ie work hardens the back.
This also produced a few dents in the surface but as there was plenty of meat on the back these came out easily with a linisher.

The annealing temp is brass type dependent but as I did not know what my brass angle was I used 600ºC for about half an hour. I was fortunate enough to have access to a +/-1º temperature calibrated furnace at work but I have also annealed brass using propane torch and a compact firebrick enclosure. I used one of those infra red thermometers to measure the temp.

The final result (esp using 3mm angle) is a heavy wide chunky pointy back so I did slim the whole thing down using a linisher with an aggressive and teh successively finer belts. On one back I removed some of the width using a table saw with a multipurpose negatively raked toothed blade.

To cut all my thin blade or tool steel stock I use this home made thin kerf cutting wheel table saw.
Its attached to 3P 1HP grinder on a VFD and also geared up to run at 12000rpm @60Hz
It has a fence (not shown) and mitre slide and is surprisingly accurate.
This is one of the most useful gizmos I have made - much better and safer than an angle grinder.

guard2.jpg

The sparks are by and large captured in a baked bean can under the table - see red arrow.
Usually I have the spark guard down but the effectiveness of the DC snorkel connected to 20L steel drum spark (or hot metal) separator can also be seen.
catchcan.jpg

Nice jig. I've seen similar ideas but not on a grinder. What size press did you use? Think a 20ton would be enough?

The one I used was a 20 ton but I don’t recall it being used to anywhere near its max press.

I've been a little busy. It took some trial and error but I made some new toys for my press. I can now bend brass strips into a acute vee and flatten. Very happy with the results. Made two 10 inch backs.

I also bought a large 12 inch bench plate shear. It cuts the .093 brass fairly easily. Cuts my saw plate like butter. Cut out four more brass strips to fold and I hope to get some more plates cut tonight too.

Originally Posted by M Williams

I've been a little busy. It took some trial and error but I made some new toys for my press. I can now bend brass strips into a acute vee and flatten. Very happy with the results. Made two 10 inch backs.

I also bought a large 12 inch bench plate shear. It cuts the .093 brass fairly easily. Cuts my saw plate like butter. Cut out four more brass strips to fold and I hope to get some more plates cut tonight too.

Some pictures would be fantastic, un less there’s a patent or something pending[emoji6].

Cheers Matt.

Brake isn't all that fancy. Measurements you gotta get right.

Shear isn't bolted yet, but I had to test it out lol. I think I will add an infeed table to help keep stock square.

Good going Matthew.

Looks like you have the start of a production line going there. Nothing quite like "commitment."

I think it is fair to say you are well and truly hooked.

Regards
Paul

You could say that...

Well I've been a bit busy lately. Lots of saw restorations. But on the building front I have gotten a few more things figured out. First my mortises in the handles for the backs. I changed up my jig but I can get them straight and square every time now. Also got myself a drum sander. Makes life a little easier. And I ordered some stamps for the brass! It'll be a couple weeks but I'm pretty excited.

Stamping milled backs is easy enough but does anyone have experience stamping folded backs? Should I do so before the bend or after it is installed?

Originally Posted by M Williams

...... but does anyone have experience stamping folded backs? Should I do so before the bend or after it is installed?

Nope, no experience of stamping either kind of back. I can see how it could be a problem trying to press something on a folded or slotted back if there is nothing in the gap to support it while the stamp is being pressed in. I guess you're in for a little experimentation...
Cheers,

Matthew

I have not had success with folding backs, mainly because I did not keep annealing the material, so I have no experience of stamping as I never got to that point. It occurs to me that stamping, presumably with a letter stamp or similar, is not much different to hammering the back flat. The danger is that the back will close up. The issue of a gap in the fold can be fixed with a piece of dummy blade placed in the gap. This will give a nearly solid piece of material to hit, but it could conceivably close up to the point of being difficult to extract the sacrificial piece of blade.

It could be that the stamping is only done when the back is in position on your real blade. There is still the possibility of the back closing up, but maybe this is not too much of an issue providing you don't wish to remove the back at any time.

Otherwise you have to stamp before folding and estimate where it will be once the folding has taken place. This may be the best bet.

Regards
Paul

Matthew,As Ian an Paul have pointed out, I think I would stamp before folding the back.

I would be worried if I stamped the back, after it was folded that I may “close” the back even more,especially up near the top of the fold which may be a little looser than down were the fold grips the saw plate.

Will you be using the stamp with a hammer or a fly press or something ?

Cheers Matt.