JasonPAtkins
Hot Rolled
- Joined
- Sep 30, 2010
- Location
- Guinea-Bissau, West Africa
The question may be more suited to Welding Web, but since it's still down, and this is actually a tool/jig making question, please forgive me.
I'm getting ready to make a first sample K joist (title is incorrect - joist, not truss), for more info see this other thread. Aside from making stands to keep the angle irons all parallel and in-plane, my other piece of prep work is to make an easy way to collapse the ends of the angle iron pieces that will form the webbing. The angle is 1-1/4" with 5/32" wall, so it's not especially difficult to form - but I want an easily repeatable way to make sure it ends up 1" wide (outside to outside) because it having a uniform thickness between the main angle runs will contribute to the uniformity of the width of the overall joist.
I can get a decent bend on it just using my Columbian vise with a solid round held in the gap. However, first, it feels like I'm stressing the vise screw pretty good, and second, if you look at the pics of the test fitup, it didn't give me a very good flat to weld against on the back side of the bend. The bend is such that it's going to be tough getting a good angle to weld the back side (the contacting side nearest the angle's outside corner).
So, how is this done commercially? I have a 25t shop press, which seems like the right tool for this job. I assume that someone sells an attachment for a shop press or iron worker to do exactly what I'm trying to do, but I can't figure out what to search for in order to see how they're doing it.
I think that because of the deflection, my two pressing surfaces (the jaws, in the vise example) actually need to be not parallel to each other, but collapsed a bit inward on the angle's open side (top side in the vise pic) - because it needs to overbend that part in order to end up with the two angle legs parallel because they're going to spring back some.
I'm getting ready to make a first sample K joist (title is incorrect - joist, not truss), for more info see this other thread. Aside from making stands to keep the angle irons all parallel and in-plane, my other piece of prep work is to make an easy way to collapse the ends of the angle iron pieces that will form the webbing. The angle is 1-1/4" with 5/32" wall, so it's not especially difficult to form - but I want an easily repeatable way to make sure it ends up 1" wide (outside to outside) because it having a uniform thickness between the main angle runs will contribute to the uniformity of the width of the overall joist.
I can get a decent bend on it just using my Columbian vise with a solid round held in the gap. However, first, it feels like I'm stressing the vise screw pretty good, and second, if you look at the pics of the test fitup, it didn't give me a very good flat to weld against on the back side of the bend. The bend is such that it's going to be tough getting a good angle to weld the back side (the contacting side nearest the angle's outside corner).
So, how is this done commercially? I have a 25t shop press, which seems like the right tool for this job. I assume that someone sells an attachment for a shop press or iron worker to do exactly what I'm trying to do, but I can't figure out what to search for in order to see how they're doing it.
I think that because of the deflection, my two pressing surfaces (the jaws, in the vise example) actually need to be not parallel to each other, but collapsed a bit inward on the angle's open side (top side in the vise pic) - because it needs to overbend that part in order to end up with the two angle legs parallel because they're going to spring back some.