sharpening ironworker bar shear

I have a little Scotchman ironworker. It shears structural steel stock fine, but
it hasn't ever worked on sheet metal (gap too big). Today I removed the lower
bar shear blade, cleaned it, cleaned behind it, and shimmed it out to close up
the gap. Now it will cut sheet metal, except in the middle. There is apparently
a wear spot in the middle, because when the blades are closed the gap in the
center is about .005" larger than elsewhere. It would make sense, because that's
where most of the flat bar gets sheared.
Seems like I could grind the vertical face of the blades until they clean up,
adding shims to replace the material ground off. I hate to think of what a new
pair of shear blades would cost from Scotchman!
I'm wondering if my plan will work. Anyone else try this? It wouldn't just be an
issue with an ironworker shear, could be about any guillotine or scissor type
shear.
If this does work, then I'm going to have to find someone with a bigger surface
grinder than I have, mine's only 12" and the blades are 14" long.
Grant Erwin
Kirkland, Washington
Reply to
Grant Erwin
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I seem to remember someone posting a message that said that the gap should be larger when cutting thicker material. Can't remember who it was. You might see if you can find more information on that before adjusting the gap to near zero.
Dan
Grant Erw> I have a little Scotchman ironworker. It shears structural steel stock fine, but
Reply to
dcaster
The manual says to set it to a gap of .005" everywhere, doesn't distinguish between thin and thick stock. I am working with some thin (18ga?) sheet metal right now and need to cut it cleanly and don't have a Beverly shear so I'm using the ironworker. It isn't hard to take a shim out afterwards if I need to.
GWE
snipped-for-privacy@krl.org wrote:
Reply to
Grant Erwin
at a shop i worked at we would send blades to machine shop to be ground on 2 edges to remake a "square" edge on the blade.
Reply to
digitalmaster
Just asking in case: Some shear blades can be reversed so that four different edges can be used before the blade has to be sent out for sharpening. Others I have experienced have two edges and unfortunately some have only one edge. Are yours reversible??? Randy
I have a little Scotchman ironworker. It shears structural steel stock fine, but it hasn't ever worked on sheet metal (gap too big). Today I removed the lower bar shear blade, cleaned it, cleaned behind it, and shimmed it out to close up the gap. Now it will cut sheet metal, except in the middle. There is apparently a wear spot in the middle, because when the blades are closed the gap in the center is about .005" larger than elsewhere. It would make sense, because that's where most of the flat bar gets sheared.
Seems like I could grind the vertical face of the blades until they clean up, adding shims to replace the material ground off. I hate to think of what a new pair of shear blades would cost from Scotchman!
I'm wondering if my plan will work. Anyone else try this? It wouldn't just be an issue with an ironworker shear, could be about any guillotine or scissor type shear.
If this does work, then I'm going to have to find someone with a bigger surface grinder than I have, mine's only 12" and the blades are 14" long.
Grant Erwin Kirkland, Washington
Reply to
R. Zimmerman
Good thinking, Randy. Sadly, my bar shear blades aren't reversible. The angle shear blades are, though.
I think I'm going to try sharpening these blades. I don't see what I have to lose.
GWE
R. Zimmerman wrote:
Reply to
Grant Erwin
You might want to stop by your local printer and ask him where he gets his blades sharpened and how much it costs.
Printers have great big shears for stacks of paper and have to get the blades sharpened regularly.
Reply to
Jim Stewart
"Costs"? Me, spend money? Actual US currency? That's to be avoided at ALL COSTS.
:-)
GWE
Reply to
Grant Erwin
Depending on the blade material, you could weld up the blade where you need more material and grind it flush with a surface grinder or die grinder. Rod can be (very) expensive, however.
Regards,
Robin
Reply to
Robin S.
I'm not sure what these blades are, but they seem pretty hard and also pretty tough, as they eat mill scale all day.
I have a 3rd blade that came with my (old, very used) ironworker. This blade was obviously used but the guy never threw it away. I set it up on the diagonal of my 6x12" chuck and I've been taking passes on it. There were some heavy wear spots about 5" long and I've got that spot down to about 1/16" but it seems sort of deepish and I don't know if I have the willingness to grind off another .010 just to see pretty all the way across. I haven't even tried grinding the face (the 2x14" side), I've been working on the top (the 1/2x14" side).
As Harold says, tool steel sure grinds a lot better than mild. Also, I have found to my amazement that my little K.O. Lee 6x12 grinder can indeed take a cut .002" deep if I limit it to .025" feeds.
GWE
Reply to
Grant Erwin
This same subject just came up in the neighborhood last week. I don't know for sure what the guy did, but I suggested that he find someone who sharpens saw blades as a business. There's a guy around here who does it and he has tooling to sharpen planer blades that are as much as 36" long. Seems to me that he could do your job.
Pete Stanaitis ----------------------------
Grant Erw> I have a little Scotchman ironworker. It shears structural steel stock
Reply to
spaco
Thanks, Pete. Up around Seattle we now have about 150 people on the rolls of our local metalworking club, many of whom are old friends by now. I won't have any trouble finding someone with a much better surface grinder than I have. I appreciate it.
GWE
spaco wrote:
Reply to
Grant Erwin
While I cannot speak for your iron worker..I have been doing repair/adjustment work on various bigger shears over the past month or so. I just did a repair job and an a full tune and tweak on both an Amada 1/4" and a Standard 1/2" plate sheer (both with 12 foot blades) and the specified clearence was .003 for stuff down to 16 ga, and then .002-001.
Gunner
"A prudent man foresees the difficulties ahead and prepares for them; the simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
Reply to
Gunner
I wound up grinding my bar shear blades on an 8x18" surface grinder over at a friend's shop (thanks, Ken!), just on the top. I got the gap out by first bolting the blades in and then holding a ground straightedge against the vertical face and testing with feeler gages to see where the gap was. It turned out that my upper bar shear arm's blade pocket is slightly out of flat, so I put a shim behind it in the middle, now my ironworker shears sheet metal fine.
Looks to me like ironworker bar shear blades can be sharpened OK on a surface grinder just fine, several times in fact.
Happy ending, just thought you guys would like to know.
GWE
Reply to
Grant Erwin
cogratulations, properly adjusted you can get a mighty fine shear out of those little machines.
Reply to
WILLIAM HENRY

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