Arbor Presses. how much power?

[J.Leon_Szesny 20]

I've been eyeing arbor presses for a little while for saw tooth cutting

but I couldn't find reference as to their actually performance in steel.(mostly leather, plastic, button setting...)

if I had an annealed piece of high carbon steel and a half to 1 ton pressure, arbor press,

we're talking about maybe 2-3 mm thick steel plate,

could I cut saw teeth with that at a rate that would make it a "non-frustrating" task

 

[Alan Longmire 2,750]

No.  If it were 0.5mm plate, yes.  A 1-ton arbor press can't do 2mm sheet easily. 

The dies will have a lot to do with that as well.  The more teeth you cut at once the more force you need.  I'll do the math after I've had enough coffee, but a one ton arbor press generates about the same force as a 1500 gram hammer swung smartly.  F=mv^2, and the v of the press is near zero.

[Alan Longmire 2,750]

So: To produce one (metric) ton of force with a 1500 gram hammer, you must have said hammer travelling at 26m/s, or basically slightly slower than just dropping it from a height of one meter.  It is a short-lived force, but that gives you an idea of what you can do.  

 

Edit:  got my units mixed up, sorry.  Just dropping the hammer would be around 10 m/s.  So a slight swing is needed to produce one metric ton on impact.  Still not a lot of force.  

Edited October 7, 2020 by Alan Longmire
I'm an idiot sometimes

[steven smith 100]

saws are pretty thin steel, probably 1mm at most, i would make something like a guillotine tool with cutting dies instead of forging dies.  

 

 

[J.Leon_Szesny 20]

I was thinking of just using a single cutter, since that would give me more ability to tooth different shapes of saws and then just have a jig below that helps me make sure the teeth are aligned properly.

im mainly interested in japanese saws for finer woodworking so, the teeth would be pretty tiny and the cutter as well would be more like, the size of a pencils cross section cut into a V, probably smaller even. 

but im really not so sure anymore 
 

7 hours ago, Alan Longmire said:

So: To produce one (metric) ton of force with a 1500 gram hammer, you must have said hammer travelling at 26m/s, or basically slightly slower than just dropping it from a height of one meter.  It is a short-lived force, but that gives you an idea of what you can do.  

I mean thats not...a lot...

[steven smith 100]

unfortunately this is one of those things that needs absolutely exact search terms to be researched, im also interested in saw making, what are the tooth cutting dies called? 

 

i have seen the hand cranked machines that can make a saw in a couple minutes but i cant even figure out how to search for those....

 

finding saw steel is another challenge but ive seen that some plaster knives or spatulas are "spring steel", this sort of thing: https://www.tradetools.com/goldblatt-100mm-spring-steel-flex-joint-knife

[Jerrod Miller 445]

I wonder if broaching would be the best solution to this?  You could possibly modify a cheaper arbor press to do broaching.  

[Alan Longmire 2,750]

14 hours ago, steven smith said:

finding saw steel is another challenge but

 

15n20 is made primarily to be saw blades...

 

Ah, Japanese saws.  Very thin, with tall teeth, and a very specific geometry. I think they do those with chisel cuts followed by a feather file.  I bet there's a video somwhere.

[J.Leon_Szesny 20]

I was thinking of having something similar to a chisel for a cutter not something like a flat punch.
maybe more like a V graver with a very high angle bevel.

here is a video of a japanese smith hand cutting saw teeth but im not totally sure about the chisels(/punches?) edge geometry and angles.

 

[Alan Longmire 2,750]

16 hours ago, Jerrod Miller said:

I wonder if broaching would be the best solution to this?  You could possibly modify a cheaper arbor press to do broaching.  

 

Exactly.  Look at pinking shears, the way the teeth fit as the dies close. It's a rolling action that puts the stress on a very small area. 

[Pieter-Paul Derks 210]

For this kind of work a small fly press would be ideal I think. For jewelry work I have also used a hand powered press that worked with and eccentric cam and lever, I have no idea how it is called, but it worked a treat for cutting small pieces of metal.

 

To my ears 2mm thickness sounds like a lot for a japanese saw, I have a decent sized Kataba, and the blade is only 0.8mm thick.

For cutting 2mm carbon steel you will need a surprising amount of force, more than any normal sized arbor press will provide.

[steven smith 100]

1 hour ago, Alan Longmire said:

 

15n20 is made primarily to be saw blades...

 

Ah, Japanese saws.  Very thin, with tall teeth, and a very specific geometry. I think they do those with chisel cuts followed by a feather file.  I bet there's a video somwhere.

 

it seems like id want something like .02" thick or maybe thicker but its hard to find anything under 1/16" (~.065") that isnt horribly expensive, a cheap saw could be longer than two feet and 8" wide or more and cost $15 but a sheet of steel that size that would work might cost $40 or more.

 

i can find expensive blade blanks with the wrong kind of teeth cut in them, seems like there are a bunch of backsaw kits, but i cant find .02" thick sheet thats 8" or wider, i think mcmastercarr has some but its cost prohibitive if i remember. https://www.mcmaster.com/metals/steel/spring-steel/1075-spring-steel-strips/  nothing long enough there

 

when i search "hand saw blade blank" or anything like it i only get industrial suppliers.

 

i want to make a japanese whaleback saw, it would probably be $200 for a 36" x 12" sheet though and id save money just buying antique japanese tools on ebay, which seems like an insane reality to me. i could probably get by with a narrower blade but ive got logs to cut and i hope to have more logs in the future. 

 

 

[Brian Dougherty 1,175]

17 minutes ago, steven smith said:

it seems like id want something like .02" thick or maybe thicker but its hard to find anything under 1/16" (~.065") that isnt horribly expensive, a cheap saw could be longer than two feet and 8" wide or more and cost $15 but a sheet of steel that size that would work might cost $40 or more.

 

It is still pricy relative to your $15 number, but have you considered 1095 shim stock?

https://www.mcmaster.com/shim-stock/shim-stock-6/thickness~0-02/material~steel/material~1095-spring-steel/

 

 

[J.Leon_Szesny 20]

I would be making the saw steel myself, so thats why im thinking in terms of 2-3mm
since I'd be having to scrape a lot of steel off to make them flat.
not sure yet how thin I as an amateur could get away with and not have it just crumble or break or who knows....

for reference
I do everything by hand, closely using the japanese traditional techniques and tools.
 

[steven smith 100]

27 minutes ago, Brian Dougherty said:

 

It is still pricy relative to your $15 number, but have you considered 1095 shim stock?

https://www.mcmaster.com/shim-stock/shim-stock-6/thickness~0-02/material~steel/material~1095-spring-steel/

 

 

 

the flat sheet seems pretty good compared to everything else ive seen, thanks, im sure ive checked that before but its still a good bit of money so i likely forgot it. the roll is a good deal but not quite wide enough for me :/

 

27 minutes ago, J.Leon_Szesny said:

I would be making the saw steel myself, so thats why im thinking in terms of 2-3mm
since I'd be having to scrape a lot of steel off to make them flat.
not sure yet how thin I as an amateur could get away with and not have it just crumble or break or who knows....

for reference
I do everything by hand, closely using the japanese traditional techniques and tools.
 

 

you should be able to forge thinner than 2mm, the thinner you go the harder it is to keep everything the same thickness.

[Alan Longmire 2,750]

1 hour ago, steven smith said:

you should be able to forge thinner than 2mm, the thinner you go the harder it is to keep everything the same thickness.

 

Doing it the Japanese way, he'll be using a big convex sen to scrape away the flats so that the edge is the thickest part, making a slightly hollow-gropund profile in the body, with the spine a hair thicker.  No drag in the cut that way.  That said, I think you could start with 1mm stock, scrape it to the preferred thickness, then cut the teeth.  Now I'm going to watch that video to see just how wrong I was about that...   

[Alan Longmire 2,750]

Okay, video watched, up the part where they started making plane irons.  I see your 2mm estimate in the tang, but the body of the saw blank looks to be 1mm before he started scraping on it.  Observing yake-ira (hardening), that steel is not a super high carbon content, probably 0.45% carbon.  It did not warp in the oil quench even though it went in kind of sideways, which impressed me.  The temper to a hint of light blue (if I'm seeing it right) is another clue it's not a very high carbon steel. The ease with which the sen removed shavings of the hardened and tempered blade suggest to me a finished hardness of no more than Rc 50, probably more like 45.  

 

As for the tooth-cutting chisel and guide, I suspect the chisel is a simple triangle with an angled face.  The V-notch in the guide is repeated on the lower part, making the chisel action a shearing cut from the bottom of the V to the edge of the sheet.  The fact he's doing that with a not-too-big hammer suggests you could do it with a small arbor press cutting one tooth at a time.  Pieter-Paul is correct that a fly press would be better, especially if you want to do multiple teeth per stroke. An open-back inclined punch press would be ideal once you figure out the tool geometry.  But I don't think those were ever very popular in Europe.  

 

What impressed me the most of the whole process was the guy hammering in the tooth set by eye.  I mean, we do that on big crosscut saws with like 2 teeth per inch, but for a pitch that fine the hammer control required to get a decent uniformity is pretty mind-blowing!  

[J.Leon_Szesny 20]

im not too sure about the lower carbon content, because the tamahagane that they used,

did show that it broke easily after hardening 
but it could be that after all the re-stacking and re-welding the content got lowered.
though they did use rice straw ash to neutralize carbon loss.
so perhaps the steel simply got quenched at a lower temp thus leading to lowered hardness

initially the tamahagane chunk got quenched at what looked to be orange temp.
and the finished saw blade was quenched at about dull red.
but with cameras and lighting its hard to trust the visuals.