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How many strokes per minute is YOUR mechanical shear??

dkmc

Diamond
What's the Strokes Per Minute of YOUR mechanical shear? I'm looking to compare an average base line speed.
Would also be helpful to know if it's a modern steel or substantial cast iron machine as opposed to a more spindly antique like mine with thinner castings that have webbing instead of solid.

So my 1914 Niagara 6ft 14 gauge shear has been around the track a few laps. And there's been some sketchy pit crew action done to it too. At that age it was probably flat belt driven back in the day. Now it's had a 2hp motor cobbed onto the drive end with 'shot in the dark' V belt pulleys added as a guess on input RPM from the looks of things. The motor pulley was probably one of those 'dual width' type but with a 1/2" belt that sits low in the groove and slips.

Had enough, it got to the point of -not usable- and I installed the smallest cast iron pulley I could find made for a 1/2" belt. Now it seems FAST... I timed it and it's about 24 strokes per min. That's hitting the pedal, letting it cycle, and when it stops, step on the pedal again. As opposed to just holding the pedal down.....which is 36 strokes per minute. Point being, it's had some weld repairs and reinforcing plates cobbed in on the right side between the cracks, between the second set of reduction gears. I don't want to run it too fast and break it worse. There is room to increase the size of the driven pulley from 5" to 6 or 7 inch, with a bit of screwing around and crawling on the floor. I'd do it if it would help prevent a catastrophic failure that's coming but I don't know about it yet. Obviously, up to a point, a minimum speed is required to have sufficient "flywheel effect" to power the blade thru the material. I'm not sure how much the motor helps to power the blade thru the work as well. I want to be -there- but not way past that to the point it's gonna stress the design and overload it....like some morons apparently already have.
 
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Bondo

Hot Rolled
Joined
May 14, 2011
Location
Bridgeton NJ
I have a 1971 wysong 1/4 x 10' mechanical shear. It has an upgraded motor at 15 HP from the factory.

It does 48 SPM when holding the bar down. That is too much load for the motor and flywheel so it starts to strain after 30 seconds.

We normally cut about 10 SPM. It does cut a few jobs at about 30 SPM. The gibs get full of oil and start making a gulping sound. That at about 2,000 strokes

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dkmc

Diamond
Thanks. I noticed this one faded on RPM as well when I did the 'bar down' test.

I have a 1971 wysong 1/4 x 10' mechanical shear. It has an upgraded motor at 15 HP from the factory.

It does 48 SPM when holding the bar down. That is too much load for the motor and flywheel so it starts to strain after 30 seconds.

We normally cut about 10 SPM. It does cut a few jobs at about 30 SPM. The gibs get full of oil and start making a gulping sound. That at about 2,000 strokes

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dana gear

Hot Rolled
Joined
Feb 27, 2013
Location
Northern califorina, usa
Vintage machinery has a bunch of operator's manuals for the older Niagara, that you can down load.
Most all mechanical shear manufactures list a total stroke per minute based on several factors such as pulley and motor size, 50/60 cycle power, AC or DC drive etc.
An example would be on our older Niagara and Pexto/Wilcox mechanical shears cycle about 45/50 strokes per minute continually. If everything is in good condition and the drives are correct, the blade condition is good and sharp as well as blade clearance is correct and the material you are shearing is within the rated capacity of the shear, then you should be able to continually feed material through the shear.
 

Strostkovy

Stainless
Joined
Oct 29, 2017
Wysong shear at work that was well made but didn't seem overbuilt would cycle once ever two seconds or so. I don't have a hard number but I expect it to be over 30 strokes per minute.
 

bryan_machine

Diamond
Joined
Jun 16, 2006
Location
Near Seattle
In our experiments with a stomp shear, it seems if the backgauge is good 12 or even 15 cuts a minute are possible (actual cuts.) I haven't tried just cycling it to see how fast it will go, but 24 spm to 38 spm to 60 spm doesn't sound all that fast for a powered shear to me (assuming it isn't some 12 foot wide 1/4" plate cutting monster.)
 

dkmc

Diamond
If it's a "stomp" shear it's foot powered no? Mine's rather spindly with the thinner olde timey webbed castings. The input shaft off the motor seems to be turning quite fast, I think around 730 RPM. What doesn't help is the sound of the straight cut gears on both sides of the machine clanging and churning away. At least gives the illusion of over speed and pending peril. Then again, too slow can be a recipe for a jamb below rated capacity as well.

In our experiments with a stomp shear, it seems if the backgauge is good 12 or even 15 cuts a minute are possible (actual cuts.) I haven't tried just cycling it to see how fast it will go, but 24 spm to 38 spm to 60 spm doesn't sound all that fast for a powered shear to me (assuming it isn't some 12 foot wide 1/4" plate cutting monster.)
 

bryan_machine

Diamond
Joined
Jun 16, 2006
Location
Near Seattle
Yes it's a foot powered (treadle) shear. And it's less than a year old, and only rated for 16ga (and that's likely optimistic for high volume.)

But given that a foot shear goes that fast, the other speeds you discuss don't seem out of line (at least with no load.)

None of that informs whether age, sketchy mods, misadjustment, etc. may be an issue.
 

dkmc

Diamond
I'm not sure a foot shear's operation applies to a power driven shear. Do people break the old cast versions of them (other than the foot treadles)? There are no gears or motor or shafts to supply momentum and shock loading. Just some discussion points...
 

bryan_machine

Diamond
Joined
Jun 16, 2006
Location
Near Seattle
True! On the other hand to operate foot shears sometimes smallish people (women in this case) have to hop up and down on the treadle (yes this is a problem) - that can't be the smoothest event for the device.

But the only times I've ever heard of them being damaged involved outright abuse - people putting bar stock into them, cutting thick stainless in a shear only rated for thinner mild, that sort of thing.
 

CalG

Diamond
Joined
Dec 30, 2008
Location
Vt USA
"Back in my aviation days....

I converted a Wysong 8 foot jump shear to air cylinder actuation.

It was a great success!

Call it 10 strokes per min TOPS
 

dkmc

Diamond
The shear is rated for 72" of 14 gauge 'soft steel'. I'd really like to get some 14ga and test it at capacity but at lower motor RPM.
That would be fairly easy with a VFD I have kicking around. I'd be looking for the lowest RPM that it would cycle thru reliably. I'm going to check my neighbors pile of scrap behind their Cincinnati 10ft x 1/4" machine. I don't need a 6ft piece, just enough pieces to cover 6ft of blade. Of course, I'm probably overthinking this, like most things shop and machine related. It's fun to me tho, and getting the machine reliable without overloading it is probably a noble cause.
 

D Nelson

Stainless
Joined
Jan 7, 2015
Location
Missouri Ida
If it’s too fast you can’t feed long cuts fast enough to get to the backstop
Don


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Bondo

Hot Rolled
Joined
May 14, 2011
Location
Bridgeton NJ
Before you test your machine, check the gaps in the blade. If there is too much or too little of a gap, it could hurt your shear and/or blades.

On mechanicals, it's a PITA. Very simple on hydraulic machines.

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kustomizer

Titanium
Joined
Aug 17, 2007
Location
North Fork Idaho
The shear is rated for 72" of 14 gauge 'soft steel'. I'd really like to get some 14ga and test it at capacity but at lower motor RPM.
That would be fairly easy with a VFD I have kicking around. I'd be looking for the lowest RPM that it would cycle thru reliably. I'm going to check my neighbors pile of scrap behind their Cincinnati 10ft x 1/4" machine. I don't need a 6ft piece, just enough pieces to cover 6ft of blade. Of course, I'm probably overthinking this, like most things shop and machine related. It's fun to me tho, and getting the machine reliable without overloading it is probably a noble cause.

We all need little projects to aggravate ourselves,

my old Wysong 48 x 12 ga does about 30 per min and around 50 with the auto cycle on
 

dkmc

Diamond
There's a misinterpretation of the question here. I'm asking about Strokes Per Minute as reference to travel speed of the blade, for one stroke. Not attempting to use the machine in a continuous cycle mode. So the length of a "part" has no bearing on this. I think that would be obvious from the description in post #1 ?

it all depends how long of a part you are doing? if its 38" good luck feeding that at 60 SPM
 

gary-sc

Aluminum
Joined
Aug 20, 2010
Location
Santa Cruz, CA USA
My Pexto 12u52 is 60 spm with the bar down, doesn't fade when used that way. We usually cut one at a time and that runs about 35spm if you get your timing in a groove. Old cast iron beast, 5ph motor, and a very large flywheel
 








 
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