I’ve had my machine for a couple weeks now and I like it a lot but I’m having issues with bend consistency/repeatability. For example I have a 12ga CR part that has one 90 degree bend with a 1" bend length. Without using any bend comp the first part will bend to 91 degrees which is pretty good. Bend the next part (still without using any bend comp) it will bend to 88 degrees. If I keep bending parts the bend angles will jump +/- 3 degrees. When I try and use the bend comp feature the angles also jumps around. I mic’ed out the material thickness and double checked my punch and die measurements and everything looks correct. I’m bend in the center of the machine every time as well. I’m kinda stuck now on what else to check. Does anyone have any ideas on how to fix this issue?
How are your parts nested when they’re cut? Ideally they’ll all lay the same direction so the grain direction doesn’t change.
If not, be ready to sort them by grain direction, and keep them faced the same direction (cut face up vs down). May not be the whole story, but it’s probably part of the issue if you’ve got them nested in various (or 90°) orientations.
All the parts were nested with the grain going the same direction and from the same sheet. Should I be bending with the grain or against the grain?
As long as you’re not getting cracks in the bend area it shouldn’t matter as long as you’re consistent.
The only other things I’ve seen that it could be material-wise is if you’re using cold rolled there’s more variation, and the edges of HR sheets cool faster and can be harder than the steel in the center of the sheet. If it’s not one of those things, then likely one of the guys from Langmuir may need to help you troubleshoot as it’s probably a machine issue of some sort.
Online “The grains run parallel to the rolling direction, and forming or bending “with the grain” requires less force because the material’s ductility is already stretched”
Some machine accuracy tests you could take:
Set a dial indicator on the table, stroke the ram out to some known value like -3in. Zero the indicator here. Jog up to some value like -0.5 (but don’t rehome), and then come back to indicator position. it should always return to position within 1 thou…
Do this a number of times. if it doesn’t always return something is up. If that first test works, repeat the same test but then home it and come back to position and check indicator.
Then check the ram to table opening distance at several intervals using calipers: -3", -2.5", -2", -1", -.5". See how well those match your calibrated ram to table opening distance.
Let me know how that goes at support@langmuirsystems.com or (833) 526-4797