cnc press brake question

[a_pipon]

Hi, at my work, we have a Metfab Rebel press brake with a Delem DA-66T controller and now we have issues with the bend angle not being the same from one side to the other (difference of 2.5 to 3 degrees on a 10 feet long 90 degrees bend in 11gauge steel). We can play with the correction on each side indepedently to make it work and there is also a general level setting I think but we never touched it in the past and it was fine and now it's suddenly not. If there is someone here that has an idea of what the problem could be, we would appreciate it.
Thank you.

 

[Fish On]

Hi, at my work, we have a Metfab Rebel press brake with a Delem DA-66T controller and now we have issues with the bend angle not being the same from one side to the other (difference of 2.5 to 3 degrees on a 10 feet long 90 degrees bend in 11gauge steel). We can play with the correction on each side indepedently to make it work and there is also a general level setting I think but we never touched it in the past and it was fine and now it's suddenly not. If there is someone here that has an idea of what the problem could be, we would appreciate it.
Thank you.

I'd imagine there's a way to adjust that within the control, but very possibly behind the technician password.

Alternatively, if it suddenly changed, I would say it's possible that one of the optical scales on the ends of the ram got bumped and is out of whack. Time to pull out the precision measuring tools and see how much BDC varies - both from one side to the other, and from the dimensions the control thinks the ram is at.

Remember that the bed is likely crowned, so be sure dimensions are all pulled the same distance from center each time.

 

[memphisjed]

If something changed other than windage it is mechanical issue.
Never a bad idea to go thru both sides and crown and retrue rams and scales. Could be simple item like a homing switch was shifted or a little bigger like a ram pin bent.
Software comp should be for last 1/32 or less.

 

[Strostkovy]

I hate the DA-66T control on our Accurl with a passion.

When we first had the issue you describe it was tooling that was warped from the factory by about 5 thousandths each.

The second time we had the issue our steel sheets were thicker in the middle and thinner at the edges. We just had to struggle through that by measuring each part and guessing the left and right corrections.

The third time we have that issue we found the tool holder was loose and was walking a little bit out of adjustment with every press. Straightening the die rail parallel to the backgauge and aligning the hydraulic tool holder to the die rail fixed this issue.

While I'm thinking of press brakes, here's a friendly reminder to stay away form Moore Machine Tool and Accurl.

 

[Scruffy887]

Are you air bending? Material thickness variation has a huge effect on bend angles and it will make you chase your tail trying to get ahead of it. Same thickness edge to edge? You may need to mike each sheet and mark LEFT RIGHT. But what if multiple bends on front and back?
Bottom bending is easier but a 10 foot bend in 11g takes more tonnage than air bending.

 

[Jatrox]

Process of elimination. When dealing with brakes always start with material. 99% of the time that's the problem. Then tooling, then mechanical