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Author Topic: paper guillotine back fence  (Read 3172 times)

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paper guillotine back fence
« on: May 06, 2010, 07:12:50 AM »

I would  like to make the back fence on my paper guillotine automated. At present it is hand operated and one turn of the handle moves the fence  10mm. The guillotine works really well so it would make sense to add some electronics rather than change it and I need to do a lot of repetive cutting which involves changing the settings manually. This  becomes tedious and leads to mistakes!

I intend adding a stepper motor to move the backfence leadscrew but leave the rest of the operations, ie clamping and cutting manually operated.

On power up I'd like to move the fence to the home position and zero the scale. After that  key in the first position, move the fence to that position clamp and shear. Then repeat the process a number of times until the card is cut, each step would be the same amount.
Is it possible to program each operation so that each stage is down to selecting a single number or something similar once the program has been set up?

I have no knowledge of any cnc work and I'm sure what I am asking is pretty basic but you've got to start somewhere---can anyone point me in the right direction?

Thanks
Re: paper guillotine back fence
« Reply #1 on: May 06, 2010, 07:27:33 AM »
How many different increment sizes would you need ?
If only a few, you could simply do this with a stand alone indexing programmable drive.
One button to HOME, then one button press for each incremental move.
Many drives can be setup for several different increments, just need a different button for each.
This is only if there are a known few as the drive would need to be reconfigured to change or add the length of increment.
Mach would be infinitely variable if that's what you need though.
Re: paper guillotine back fence
« Reply #2 on: May 06, 2010, 07:33:24 AM »

Thanks, for the suggestion. I dont need many different sizes and my first thoughts were were for a programable divider or perhaps an Electronic Lead Screw but I thought that using Mach would give me some experience of it and be more future proof especially if it would ramp up and down as it is moving the fence.
Re: paper guillotine back fence
« Reply #3 on: May 06, 2010, 07:54:08 AM »
Sure it would. You could use Mach just fine.
The indexers have S-curves and ramp/accel/decell profiles as well.
Would just simplify the fence a bit.
You will like the versatility of Mach though.
Have at it !

Offline Hood

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Re: paper guillotine back fence
« Reply #4 on: May 06, 2010, 08:43:09 AM »
As Russ says an indexer would do what you wanted but if using Mach it   would likely be easy enough to do with a few buttons on a screen which you could make up.
Making a simple screen, with a Home button, maybe a DRO and a few buttons to move different increments would take you 5 mins to make.
The buttons would just contain some VB, for example

Code ("G91G0X10")

That would move in 10mm increments.

Code ("G91G0X1")

That would move 1mm increments

Code ("G91G0X-10")

Would move back 10mm increments etc etc, sure you get the idea.

Any help you needed you will get here on this forum, its full of great people.
Hood

Offline kf2qd

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Re: paper guillotine back fence
« Reply #5 on: May 07, 2010, 05:49:55 PM »
Big question is what kind of drives are you using? Some drives have much of the needed power built in. You might be able to do all the control through a serial port.

 As far as program requirements - for controlling a 1 axis fence it would be fairly easy to write a program for an older DOS only machine that would position the fence, have presets , and be able to move to a user enterred position. Would even be possible to have it do a sequence of moves based on inputs (also through the printer port or keyboard)

Mach3 is a bit of overkill for the application, but it would not require much programming to use it, as long as you weren't trying to create too many special buttons and other functions that are not typical in a CNC machine.