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CRS is full of mechanical stress from the cold rolling process. That's one of the reasons it goes "bananas". How are you holding/fixturing the pieces now?
Dick Z
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Trying to machine this profile in 3/4"x3/4" CRS, 24" long. Problem is after 1st side is machined, part looks like a banana and must be pressed back into shape to do the 2nd side. Angle on each side is 20deg. Any ideas? I'm very close to making my own machine with a spindle on each side and machine them both at once. More on that later if needed. Still thinking there has to be a way to do this simply.
Greg
CRS is full of mechanical stress from the cold rolling process. That's one of the reasons it goes "bananas". How are you holding/fixturing the pieces now?
Dick Z
DZASTR
In a jig using the 2 sides (top and bottom on photo) to do the first cut. But I have to take it out to flip it for other side (in another jig). That's when it warps. Once pressed back into shape, it works fine. Trying to avoid that operation. I also don't want to stress relieve before since I have a lot of these to make in the future.Originally Posted by RICHARD ZASTROW
So, when you take it out after the second operation it does not warp again? Or are you saying at that point, you do not care if it is warped or not?
http://www.kirkcon.com/
It is. But I can deal with it because it get's inserted (the narrow end) into a straight slot and plug welded from the bottom. This straightens it out.
Greg
If I were going to run this job, I would set up 3 vises with extra long soft jaws on my mill and run it as in the first picture. Then I would cut some extra long soft jaws to hold and cut it as in the second picture. I would let the vises and my hammer do all the straightening that was needed.
http://www.kirkcon.com/
Ya, that's how it is setup now (except with a fixturing jig for many bars at once). Problem is I need to do a good 1000 of these at a time. I think I'm gonna build something like this picture. Just need to figure out HP and tooling (thinking 1" or 1-1/4" indexable endmill, APKT or the like, 2 or 3 inserts) to be able to cut everything in one pass (just under 1/4" doc at thickest point). I don't care if I have to go 6ipm at 500RPM. I can make a feeder and have it all automated. I can make it weigh a ton and as rigid as possible. I don't even care about finish, it all gets galvanized after welding anyways. All that's important is angle and repeatability in same batch.
I think the point was your jig was not working and you had to straighten each piece before proceeding. My solution takes out the straightening step.
If you are going to build a machine, you might want to go horizontal with a finish form tool and with some stock and part guides and feed rollers. Place the bar in one end and it comes out the other finished. Probably want to shoot for the 10 HP range.
http://www.kirkcon.com/
Sorry for the confusion. I wanted to see if there was something I was missing and was a way to make this part without it bending between the 2 steps.
As for 10HP, on each spindle? Or 5 on each, 10 total? Seems like an awful lot. Yes, the rollers are actually pictured on the picture (although very feint). Will be using die springs on top and one side to squeeze everything together for positioning. My problem is the 10HP. Will be running it on 550V, but that's still a bear of a motor. I was thinking more 2HP on each spindle (another seperate motor/gearbox for the feed). As I said, don't really care if it goes slow. Trying to limit costs.
I was referencing 10 HP for the entire machine, power feed rollers and all.
http://www.kirkcon.com/
You might consider starting with some 7/8" or 1" bar and rough three or four sides before cleaning it up in a second pass.
If you're going to consider a special machine... consider sawing, w/ 2 saws opposed at the desired angles, staged with supporting rollers.
Looking to me like you need to stress relieve the mat'l first...
I'm curious why you need CRS as opposed to HRS for this part... nonna my business, of course...but ... (I personally despise HRS, but there's times when it's just plain easier)
...For the quantities you're looking at, you might also consider
Cold Drawn Steel, Cold Drawing, Hot Rolled Steel, Hot Rolling, Hot extruding, Extruded Steel Shapes, Steel Extrusions, Cold Rolling, Cold Forming, Roll Forming Manufacturing Processes
Would be worth a quote.
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