I don't think so. Pretty common in my experience. Have you done a lot of work with fabs this size?The pattern looks way too consistent to be the part warping IMO.
I don't think so. Pretty common in my experience. Have you done a lot of work with fabs this size?The pattern looks way too consistent to be the part warping IMO.
Yes, a lot and bigger too...I don't think so. Pretty common in my experience. Have you done a lot of work with fabs this size?
Same here, and a lot of experience cutting large fabrications. I have seen them be very neat in their movement...it very much depends on the fab geometry and clamp arrangements. If the machine cuts straight otherwise and the job isn't moving on the table, I'd be very surprised if this was not movement due to stress relief.Yes, a lot and bigger too...
Look at the pattern, it's a perfect criss-cross in the middle of travel that blends perfectly at either end of travel.
Fabs warp of course, but they don't tend to be so neat about it...
I have found that not to be true with thin sections. Thicker ones, I agree. I am going on the assumption that he knows the machine well and this is an unusual occurrence. Machine geometry issues are usually not something that happens overnight.A36 doesn't keep a whole lot of stress internally, unlike 1018/cold-rolled steels. Any "stress" coming out of the part, would be from welds pulling on the pieces during welding.
Possible, but with any sense, kept to a minimum.
The surface-scale being cut in only one direction - and not the other - is a big clue that something within the machine itself is moving about.
I have found that not to be true with thin sections. Thicker ones, I agree. I am going on the assumption that he knows the machine well and this is an unusual occurrence. Machine geometry issues are usually not something that happens overnight.
Happy to proven wrong on this one!Well idk what the root cause is. The machine is straight, best I can tell. I can’t get “any” movement with a 6’ crow bar. Checked table slop, rotation, head, etc
Sharp inserts made a big difference. But something is still moving a lot. I think it’s the slats but I just wouldn’t have expected it. Next time we will do a better job planning clamp arrangement. And make from durabar!?
thanks for all the ideas.
I’m really settling on this weldment being the problem.
True. This might be more like 3 vises but I get your point.Just think about this: take a piece of A36 3/4x6” 4’ long and put it in 3 6”vises. Using a 4” face mill try to cut it flat. What is going to happen?
The part is moving around like crazy.
You got that right........That's why this business is so fun. Just when you think you have a few things figured out, something doesn't work the way you thought and you learn again.
If the table is pitching on the ways and you cut in one direction only, it will look flat thoughI feel if you switch from a zig zag facing pattern to a unidirectional pattern that will tell a lot about if it is the machine or the work. If its the work I would expect to see the same pattern with both facing strategies. If it gets better with a unidirectional pattern then I would think it is machine related from cutting forces.
That's my point. If it is "flatter" cutting in only one direction then the machine is suspect. If it maintains the same stepped pattern when cutting in only one direction then the work itself moving from stresses is suspect.If the table is pitching on the ways and you cut in one direction only, it will look flat though
And that was more or less the goal. We are the customer and I've got some pretty low standards.If the table is pitching on the ways and you cut in one direction only, it will look flat though