PLC used with CNC machines

have been looking at different PLC's for a application that i am working on. witch is a cnc

retrofit i notices that some companies are using PLC equipment and a cad/can software package

that runs the servo controllers & the PLC runs the spindle, valves, pumps, ect, ect.
i was wondering if anybody out there knows of a software program that would run this type of deal

(the idea i need) you would write the plc program to 1 start the hydraulic system start coolant

and so on after the basic machine functions are running then i could enter the X.Y.Z. coordinance

for the AXIS that run the servo motors. i would need the PLC program setup so it can be password

protected so it can,t be mistakenly edited and the all the user would need to enter the

coordinance for the AXIS. when the start button is pushed the PLC ladder program would scan and

start what was needed till it got to the coordinance for the AXIS then the servos would cut there

path that is programmed when the cut is finished it would alarm the operator that the process was

finished.

i am trying to explain what i need as best as i can if anybody can help please contact me at

[email protected] or point me in the right direction. thank you for your time. Robert.

http://www4.ad.siemens.de/-snm-0135...6&wttree=cs&foldersopen0=-169-677-&jumpto=677

check this out

Two more companies that I know of that do CNC programming within a PLC or PC based software are:

B&R
http://www.br-automation.com/US/index.htm

Beckhoff
www.beckhoff.com

I have not used Beckhoff, but I am told that it is a good system. I have used B&R and it works for what we need it to do.

Is this.............

A system that will run the same part day in and day out?

Or do you need true 3 or 4 axis control that you can setup quickly and efficiently?

A off the shelf PLC could be made to work to control a CNC like machine. The only problem is that part code programming and execution would be a monster to enter. Wouldn't be bad for a machine running one part day in and day out.

If you need a true CNC controller then I would check with GE FANUC, MITSUBISHI, OR Allen Bradley for a CNC package to do what you want.

CNC's are PLC's but with a very elaborate control program. By the time you finish the programming to achieve the functionality of a G-code CNC package you will be an old man and the machine will have rusted away.

The main benefit of a packaged CNC controller is the fact that they operate off of industry standard "G-Code" and any machinist with CNC experience can easily program the part profiles into them.

Elaborate a little more on what your are trying to actually achieve and it will assist us in helping you further.

Dave

If I could digress a moment while we are talking about CNC.....

Mtn_Bkn_Dave:
Good to see you know a bit about CNC.
We have a baby 3 axis (4'x8') CNC router here we got about 3 months ago from the U.S. It is used for milling up moulds for a press that compresses dried sphagnum moss into 3D shapes for hanging baskets which we export to the US. So if you see moss lined baskets over there, chances are they come from here.(This is not advertising!)
Using Prodesktop for layout, VisualMill for toolpathing and Yeager Post.
One thing we really want to do is "reverse engineer" using some sort of 3 axis gcode generator. Know any good tricks?

OAS,

Your in for a real treat! I used a PLC to run a milling machine. This required a seperate program, or subroutine for each part. This turned out to be a hugely complicated program with a lot of consulting from the machineist, etc..In the end it didnt turn out to be practacle for small runs. Mostly because the machinist/user couldnt program it. A true CNC controller may be your best bet.

Good Luck with it.

Mike

Hmmmmmmmm

Azecraze,

Are you trying to reverse engineer the controller or the G-Code?

If you are trying to build another machine and the tooling load isn't too heavy there are some fairly cheap 3 axis CNC bridge style actuators that may do the trick. Build a mount for the router, plug it up and go.........I used one a few years back for a glue system to apply a glue bead to parts for the front cap of semis. It worked really well.

Let me know what you are trying to do.............Always remember......It can be done.........somebody built the one you have now!


Oh and as for the Beckoff system mentioned in an earlier post.....Looks like an awesome package....
Appears to have all the goodies needed for a good cnc package. Pretty sweet that it has cutter comp and tool length offset built in....

Dave

Just as a sideline, we have this theatre group, and like to make up models of things. Anyway we want something that you can trace over a prototype and generate gcode from it to scale up/down make as many as we like.
We have a bit to do with Weta Studios here in NZ (Lord of The Rings)
and they have these really expensive things like holographic photography and such like to create models from a prototype.
We want something a bit simpler. Something to generate gcode from the posistion in the axes.
I think this is a bit removed from the thread topic.