Machine Automation

[rrossey]

I require help on automation of a punch press. I have added a X Y table to the press and propose to add two stepper motors from Automation Direct to the two axis of the table.

The operation will be as follows:
On each stroke of the power press (operating at 45 strokes per minute) the X-axis indexes the material for the next hole in the row.
After completing 5 strokes, the Y-axis indexes the material for the next row.
The operation continues for 15 rows and then Y-axis brings the table to the starting position and the operation stops.

The stepper system is for the purpose of convenience of changing the number of holes in a row, the number of rows, the distance between the holes and the distance between the rows for a variety of jobs.

Is it possible to control the above operation through a PLC only?
Or
Do I need some software on computer to control the operation?

If both systems are possible, which one is cost effective and simple to operate?

Thanks,
R. Rossey

[rrossey]

This is in continuation of the automation of Eccentric Punch Press.
I have installed Stepper motors, Drivers and Power supply from Automation Direct and a PMDX-131 Breakout/Mother Board.
On the computer Mach 3 for mill is installed to run the system.
Now with G code, the X and Y axis can be moved as per the requirement.
The problem is I do not know how to incorporate a limit switch signal from the slide or shaft of the eccentric press, so that the X-axis should index only after the punch tool is out of the job.
Alternately a time delay can be incorporated in the G code so that X axis indexes after a particular elapsed time.
Please help how to put a time delay in G code, or how a signal from a switch can be incorporated in the program?
A similar operation is running in this link.

YouTube- Sheet metal punching on a CNC

YouTube- Sheet metal punching on a CNC

[BobWarfield]

Cool video!

I like those CNC punch presses. Somewhere I saw a little one set up similarly that would be handy. It was tabletop.

Anyway, probably lots of ways to accomplish what you are looking for. Here are a couple of thoughts:

- You can program a dwell, which is a time delay where the machine waits. Mach3 lets you do dwells in seconds or milliseconds depending on how you have it configured. G4 is used to program a dwell.

- If you want an operator-controlled pause, you can use M1, which stops until the operator hits Cycle Start.

- You can write some custom VB code that would wait until some switch closed before proceeding. I'd head over to the Mach Support Board (either Yahoo or the one on the ArtSoft site) before attempting that.

Just using the G4 dwell seems like an easy way to get going.

Best,

BW

[rrossey]

Thanks Bob, I liked your website, a lot of information and data.

I tried G 04, it worked but the problem is that the press is driven by a flat belt. there is slipage and the motor speed also varies. At some time this will not work.

Taking command from a cam switch on the eccentric shaft is the best solution. I will try Mach support group as you suggested.

On a CNC mill when 4th axis is added, how the signal is incorporated in the code that the indexing is complete, the next operation can proceed?

[BobWarfield]

A 4th axis will work like any other--Mach3 assumes the operation completes when it has finished sending the appropriate number of steps to the axis. There is no feedback.

I'm confident there will be some way to do this that the Mach boards will be able to help you with.

Best,

BW

[rrossey]

Wish everybody a Merry Christmas and Happy Holidays.

There were no suggestions from the Mach support group

Bob, after reading your project, I think I have to operate the G-code "Single Block". In Mach 3 screen the Single Blk is ALT-N on the keyboard stroke.
If a limit switch operates parallel to this key, on every stroke of the punch press, one block of G-code will index the table.

Now I have to go for a keyboard emulator board, I-Pac2 or I-PAC4 interface.

Any suggestions?

Thanks.