Flying shear - GIF

[Altair]

Flying shear.




Previously:

Throatless shear - GIF
1913 Humongous Mesta shear - photo
Hydraulic demolition shear - GIF

[Frank S]

Flying shears are quite common on roll form equipment they move with the product being formed which does a couple of things the mass of the roll form cassette does not have to be stopped and started this reduces wear and tare on the machines plus insures product uniformity a huge important other advantage lower energy cost for production since the motors never stop or slow down, the increase of production is not bad either.

[Bcampbell1989]

At a tube mill I used to work at, all the mills had flying shears, except they traveled about 18” and sheared so fast you could barely see it. Our tool and die guy had heavily modified them to last upwards of 2 years, originally they on,y lasted about 2 weeks. I worked in maintenance and was the only person besides him allowed to rebuild them. Man was it fun to do, lots of hand fit parts that their final dimensions were hand scraped to fit at time of rebuild. I realLy miss working with him and rebuilding those dies. The tube mill I currently work at uses flying saws and we don’t get to rebuild anything, everything is bought new and it really is no fun not getting to rebuild stuff. That first tube mill will likely remain my favorite job I’ve ever had

[Frank S]

I went to An Auction in China back around 2008 in the auction there was a "C" & "Z" purlin roll form made in Germany up for bids it had 27 rolling stations and the new Chinese mills had only 15 forming steps. We bought a new Chinese roll form with all shear die sizes from 90mm "C" through 200MM"C" and they almost gave us the one from Germany I think Saad only bid the equitant of about $5,000.00 for it and no other bids were turned in as no one wanted an older machine I think he only bid on it because I told him I could make a better machine out of something 20 years old than a brand new one would be. once both machines were shipped to Kuwait and we set them up I had some guys replace a lot of bearings on the old machine the rollers were worn from years of service so we put them in a lathe with a large tool post grinder and re ground them the old machine couldn't run meter for meter of the new machine but it could roll 3mm thick material just a little thicker than 12ga. the new one only 2mm thick the hydraulics on both flying shears worked much better once I installed 10 liter accumulators on them to have a stored ready pressurized volume for travel and shearing

[hemmjo]

I am wondering what might be upstream of that shear. Or are those 4 strips coming off of different coils? Is there one wide coil and a slitter? Or perhaps those are still hot from the rolling process?

[Frank S]

I am wondering what might be upstream of that shear. Or are those 4 strips coming off of different coils? Is there one wide coil and a slitter? Or perhaps those are still hot from the rolling process?

If you look at the freshly sheared ends as opposed to the dullness of the edges, makes me inclined to think they are hot rolled strips from 4 separate coils their thickness would not be indicative of having been run through a slitter either as slitters are more commonly used on thin gage metal.
The line is most probably designed to accept up to either a meter wide or 4 foot wide coils of metal with the de-coiler leveling rollers and shear being utilized to produce the maximum amount of material possible. These strips look like they may be on the order of being say 10 mm or 3/8" thick and 200 to 250 mm or 8 to 10"wide, and about 6 meters or 20 feet long.
What I wonder is if I am correct would they have say 20 coils or 50mm or 2" material running at the same time for a production run of that size material? if they did would they have top rollers on the feed side near the shear to hold everything in place

[Howder1951]

We had a similar shear like that and we called it the pendulum shear, and it was big, further down the steel rolling line we had a rotary flying shear that would have those blades moving about 50 kph on our fastest products. It had two blades synchronized to the product speed.

[Bcampbell1989]

Another thing I found really neat about my experience with flying shears is it did 2 cuts in one stroke. the cutting die mechanism was cammed so that a blade would run straight across the top of the tube putting a flat on it before the shear blade came down and actually made the cut. Without the flat (cross cut) the shear blades would run off one side of the tube and break the blade and likely crash and destroy the whole die.

[mwmkravchenko]

Thanks for all the explanations. I enjoy reading them guys! Frank and Bcampbell especially.