Help with press brake manual... Experts needed.

[rjahr]

Hey guys, I've got a big problem, I've got an Adira press brake with a Pro-Mek CNC-402 back gauge. the problem i'm having is the back gauge is off in it's settings and is not within it's tolerances... So playing with the settings I can get the machine to be accurate when the backgauge is back 20 inches but when I move it closer i.e. 5 inches then the distance from the backgauge to the press is more like 3.5 or 4 inches... Its like the closer it comes in the farther off it becomes. I will try to attach the manual I have with it along with some setting sheets that I have tried.http://mail.bellarmine.edu/exchange/...8.pdf?attach=1
If you guys can't see the attached file please let me know and I'll post it differently, Thanks guys.

[Al_The_Man]

That link asks for a user name and password!!
Al.

[pixburghenat]

....right, it looks like you used your email to attach the file.



but if your backstop uses one of those spinny dial thingeys, then I say you have a screw loose or something is slipping or worn out.

I used one with a setup like that and the gauge couldn't be trusted.
I used layout lines and I made a centering gauge that slipped over the male die and lined it up with the layout line.

If there were many pieces to do, I used the back stop once I had the thing set.

Same was true for the big shear, dial was close but I always used a layout line and the backlight, set the stop once I had it right.


Scott

[rjahr]

here's the attached file

[neilw20]

Setup Parameters: Check your parameters agains the table in section 5.
If you are going to change anything, write down ALL the existing values before you start to experiment.
Look at items 18 and 33 in particular. Both of those will probably be the same.
Tell us what you find for each of them, or show us the whole table.
Don't just TRY things. That is doomed to failure. Analyze the problem to fix it.

[Al_The_Man]

Originally Posted by pixburghenat = but if your backstop uses one of those spinny dial thingeys, then I say you have a screw loose or something is slipping or worn out. Scott

I think what Scott is saying is if the system uses a Linear scale for measure but uses a Rolling Ring mechanism, and the mechanism slips, you will get error, if the measuring system is an encoder on the motor with ball-screw with no chance of slipping then it could be you need to recalibrate the scaling or resolution, this is done by the look of it with YKENC & XKENC parameters.
Al.

[pixburghenat]

...oops....sorry, I didn't see that it was CNC.

Thanks, Al and Neil.

You are right again, if the encoded is on the motor like the manual says, then it could be slipping.
On an old Burgmaster, the encoder was on the end of the ballscrews, only held in place by tiny set screws.
After a while they would work loose and misposition.

Scott

[rjahr]

From what I've gotten already... I had to change the encoder constant area to get the results I've gotten already... I don't know what else to change.. I've got no IDEA what XKENC means. From my understanding the servo does so many revolutions per sec or per min... and I need to tell the machine how many revolutions in order for it to get the correct mm or in. And I have gotten that on the one size but I don't know why it would be different on the other..

[neilw20]

That is the encoder multiplier constant.
Put ther back guage at say 20"
Move it 15" to say 5"

If it moves say 16" then 15/16=0.9375.

Multiply the constant you have by 0.9375 and try that.
It may be the inverse. You might have to multiply by 16/15=1.06667

You should be able to hit it first time if you measure and calculate correctly.

[Al_The_Man]

Originally Posted by rjahr From what I've gotten already... I had to change the encoder constant area to get the results I've gotten already... I don't know what else to change.. I've got no IDEA what XKENC means. ..

What are you changing at present? The encoder scaling shows XKENC parmeter section 4.2
Is it a rotary encoder on the end of the motor, or linear scale system?
If linear, then you may have a mechanism called a Rolling Ring, which if mis-adjusted causes error.
If the error is consistent, then it points to scaling parameter.
Al.

[rjahr]

how do I change the scaling, I had to adjust item 18 to 104 to get the desired results so far... how do I calculate XKENC. I don't know how to calculate RESOL

[rjahr]

I think I have it all setup now... anyone have any info on a automec 300 that can help me on that model now... thanks for the help guys.