Converting Conventional Hydraulic Press Brake to CNC Press Brake with PC

Friends, I am planning to have press brake at my company and it will be better to have CNC press brake ( at least NC).
Basically I planned to buy a simple manual press brake with out any kind of automation and now i want to get it converted to CNC / NC press brake.
I need your support as i dont know where to start?
Is it possible to convert the same to CNC controlling via a PC
or is it better and easy to convert the same to an NC one.
Please let me know your opinions and views.

There is already a previous post here somewhere with, IIRC a video of someones build and CNC conversion.
Al.

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Originally Posted by Al_The_Man

There is already a previous post here somewhere with, IIRC a video of someones build and CNC conversion.
Al.

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Thanks but he talks more about making the machine and less about the electronics..... I will have the ready machine and only want to do electronic and controller stuff........

You could do it cheaply with a system like Mach, but it is best when you can make the custom operator screens that are unique to the Back gauge and press.
I retro-fitted a few using the Legacy Galil motion card, and used an older screen software they produced for it.
See post #5.
http://www.cnczone.com/forums/bendin...backguage.html
You will need to build the mechanics and obtain a servo for the back gauge and a linear scale for the press and some way of indexing the ram accurately.
Al.

is there any other way cause i have just saw that we can use micro controllers from old scanner and have control on steppers. the only thing is can we have real time heavy duty steppers on the controller?

Al, what did you do for safety on that build? I don't see any light curtains in the photos, did you use 2 hand trip?

Here in the US, all power presses are required to have at least one of 2 safety systems.

One system is light curtains, which prevent operation when the operators hands are near the pinch point.

The other system is 2 hand control, where 2 buttons have to be pressed simultaneously to bring the ram to within a quarter inch of the work, at which point control transfers to the foot pedal.

Decades ago it was routine for a press brake guy to be missing at least part of a finger, but fortunately that era seems to be ending.

-Jim Hart

Quote:

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Originally Posted by Boltz

Al, what did you do for safety on that build? I don't see any light curtains in the photos, did you use 2 hand trip?

Here in the US, all power presses are required to have at least one of 2 safety systems.

One system is light curtains, which prevent operation when the operators hands are near the pinch point.

The other system is 2 hand control, where 2 buttons have to be pressed simultaneously to bring the ram to within a quarter inch of the work, at which point control transfers to the foot pedal.

Decades ago it was routine for a press brake guy to be missing at least part of a finger, but fortunately that era seems to be ending.

-Jim Hart

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@ Jim,,,,,
Let the machine build first and then we shall have a discussion how to make it safe.
and also if you can help me in the issue please do it.

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Originally Posted by aadityadengle

is there any other way cause i have just saw that we can use micro controllers from old scanner and have control on steppers. the only thing is can we have real time heavy duty steppers on the controller?

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Like I mentioned, you need software that not only controls the ram and back gauge but also is capable of creating useful operator screens.

Quote:

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Originally Posted by Boltz

Al, what did you do for safety on that build? I don't see any light curtains in the photos, did you use 2 hand trip?
-Jim Hart

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Light curtains were added soon after.
Al.

I know VB and can do much more in that. I can do control through VB. only problem is how to drive Steppers / Servo through PC.

DELEM OR GALIL ?????????????????????
BETTER????????
CHIPPER?????????
EASY?????????????

Hi,

My situation is a little similar to yours, here's what I have:

I have a 1984 Pacific Press 225 tons x 10 feet. It originally came with a control that is about 50% operational and no one at the company that made the control ever remembers them making controls for any type of machine. Apparently they've moved into manufacturing railway parts and its been that way for 30 years. Currently with the original control I have no control over over the back gauges, but everything else work and the machine is making parts. I'll post a build after everything is said and done.

As far as the motion control is concerned, I'm switching the control over to Linuxcnc and using Mesa Anything-IO FPGA and daughter cards. I don't think you'll be doing anything worth-while using an mcu from a printer or scanner. I think you are under-estimating the requirements of programming motion control if you think you can write your own controller in VB.

At the very least, you're going to need to:

1) Control the position of the punch. For this you'll need, 2 linear encoders and the ability to read the quadrature signal they generate. You'll also want to read the pressure on the punch, for this you'll need two analog inputs. Assuming the machine you buy has a hydraulic cushion with accumulators on the die holder, you are sitting pretty, if it doesn't you'll have to measure the line pressure going into each cylinder which means you'll have to filter out the over-pressure hammers from when the different valves open and close. You'll probably have to add accumulators to each cylinder to absorb some of that hammering. After you have the ability to accurately read the position and the force applied to each side of the punch, you are going to then have to be able to control the pressure applied to the cylinder in both directions. Your manual machine will probable have 3 solenoid valves for every port of each cylinder to control direction and speed. That's 12 valves you'll need to control... or you can replace the 12 with 2 or 4 (depending on the configuration of the valve) analog or digital (pwm) servo valves. You'll need 2 or 4 more analog or pwn outputs on your controller. Then after all that's said and done, you'll need to consider limits and interlocks and program them in to keep things from doing what they shouldn't you or your operators do something stupid. This is easiest in ladder, one of the nicer features of linuxcnc.

2) Next you'll likely want to control the position of the die. Allot of machines have the ability to move the die holder forwards and backwards to do things like hemming etc. Other machines, like mine, have an adjustable stop inside the die holder that function as a depth gauge. When the stop moves up, pins in the die also move up. When the punch bends the metal and reaches the pins/stop, the pressure increases and you're control should be programmed to return the die a pre-established amount when this happens. Even if you don't have a machine with adjustable stops, you should be reading and reacting to pressure settings so you don't apply, say, 225 tons to 1 feet of tooling that's only made to take 25 tons per foot of tooling. Tooling is ridiculously expensive, and worth every penny if you want to produce any kind of quality in your results. Needless to say that your machine should have interlocks in place to protect your tooling.

This is just the very basics. Add to that things like, safety devices, back gauges, lift supports, operator interface a gcode parser and you start to build a pretty set of reqs.. All of which needs to be controlled simultaneously and in real-time.

Based on my own experience, here's what I would do:

Buy the bending brake first. Get ALL of the manuals. Fix it until its working in production. Figure out and memorize every single detail of the electrical and hydraulics of the machine until you know it by heart. Once its in production you'll be able to figure out A) What you control needs really are and B) What you'll need in regards to IO and control programming and how much that'll cost.

If you do decide you want to go through the time and expense of automating the machine. I'd suggest linuxcnc over any other option short of a ready made industrial press brake control. Simply put, you're going to need real time analog inputs and outputs, quadrature, closed loop control, and ladder logic to come up with anything worth putting to work and that won't self destruct and mame someone in the process. I won't even go into how silly it is to think "an mcu from a scanner" would work or programming it in VB (VB in real-time embedded applications?). On the other hand, there are some serious high end MCU's (the 32bit AVRS come to mind), that if you were feeling masochistic, would certainly have the IO's and the horsepower to be the main controller. Even then you'd still need dedicated hardware for pulse generation, pwm, analog and quadrature not to mention that this would be a project that would take many man-years worth of design and programming to get anywhere thats useful. Linuxcnc with some Mesa hardware gets you to the point to where you just need to program the working logic behind the machine and Linuxcnc and Mesa do all the real-time grunt-work for you.

Dangercraft

Disclaimer: In a previous life I was an embedded systems designer/programmer for timing sensitive applications. Now I work on web sites and web application back-end logic for industrial concerns and have a fabrication and machine shop as a hobby/vice. I have no relation to Mesa or the Linuxcnc project.

3 1/2 year old thread!
Al.

If you want to convert it into CNC press brake, then you need to change both the wire line and electrics. It's a big project. I believe without the help of various tools, you're not able to finish this.

I know it is old discussion but just to leave my comment. Don't know the amount of work but more reasonable to buy NC machine at start, they could be quite cheap from Asia.