Reply with QuoteWhat or how is the 25HPmotor controlled at present, the only Rolling m/c I retro fitted was Italian made and controlled previously with a PLC, I converted to CNC, but the pressure rollers were controlled hydraulically.
VFD on a 25HP Rolling Mill
I'm proposing converting a cold-rolling mill to CNC control. The process involves controlling the 25HP AC motor to very slow speed, stopping at a programmed position within an 1/8" (based on linear scale feedback of the product), downfeeding the top roll with servo motors, and reversing. Taking multiple passes.
I'm a CNC guy, so perhaps I'm guilty of having a hammer and everything looks like a nail.
ANY insight on how to do this would be greatly appreciated!
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Re: VFD on a 25HP Rolling Mill
What or how is the 25HPmotor controlled at present, the only Rolling m/c I retro fitted was Italian made and controlled previously with a PLC, I converted to CNC, but the pressure rollers were controlled hydraulically.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: VFD on a 25HP Rolling Mill
On, off, reverseOriginally Posted by Al_The_Man
Last edited by 8sigma; 04-01-2022 at 11:02 AM. Reason: added pic
Re: VFD on a 25HP Rolling Mill
It appears to have a fixed gear reduction?
For any further control it would prbabally require a fairly large VFD of some kind.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: VFD on a 25HP Rolling Mill
Hence the reason for the question.
I don't have any experience installing VFD's and before I commit to buying the machine I need to be fairly certain it's going to work.
Re: VFD on a 25HP Rolling Mill
Are you running it 230v or 640v?
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: VFD on a 25HP Rolling Mill
A VFD will run the motor, but a VFD is not a positioning device like a servo drive. Having said that, with a good motion controller (Galil) and the amount of gear reduction that machine must have, I think you could pull it off.
Jim Dawson
Sandy, Oregon, USA
Re: VFD on a 25HP Rolling Mill
Running at present at 63rpm and wishing to stop within 0.125" could be done probably with a VFD with a encoder option., I did a similar thing on a machining centre.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: VFD on a 25HP Rolling Mill
I think it's currently wired 440. I could do either. I haven't purchased it yet.
Re: VFD on a 25HP Rolling Mill
Thanks SO MUCH Al for the feedback.
I was thinking of putting an encoder on it, but ultimately the length is going to be monitored by a linear scale.
As the workpiece gets reduced in size, the length will grow substantially, according to my calculations ~50% based on reduction in cross-sectional area. The length of the reduction needs to be controlled within a specified distance to each end of the workpiece. That's where the linear scale comes into play.
Sorry for the ambiguity. It's a proprietary product. And the quote I got for a new machine was ASTRONOMICAL. Nor did it include controls beyond stopping the motor based on a manually set proximity sensor.
I priced out everything including a contract controls engineer for a year, and I'm less than half what I was quoted.
I thought about stripping off the motor and drivetrain, and running the rolls on servo motors, The existing motor and drive train are in GREAT shape so if I can get control of the speed I think it will work.
I'm spending other people's moneyso I don't want to come back later and tell them I need another $50K or something to make it work.
Re: VFD on a 25HP Rolling Mill
It's not going to be cheap for the VFD Drive to run it, so allow extra if you go ahead with it, does it have much inertia as it may be hard to stop if the inertia is highThanks SO MUCH Al for the feedback.
I was thinking of putting an encoder on it, but ultimately the length is going to be monitored by a linear scale.
As the workpiece gets reduced in size, the length will grow substantially, according to my calculations ~50% based on reduction in cross-sectional area. The length of the reduction needs to be controlled within a specified distance to each end of the workpiece. That's where the linear scale comes into play.
Sorry for the ambiguity. It's a proprietary product. And the quote I got for a new machine was ASTRONOMICAL. Nor did it include controls beyond stopping the motor based on a manually set proximity sensor.
I priced out everything including a contract controls engineer for a year, and I'm less than half what I was quoted.
I thought about stripping off the motor and drivetrain, and running the rolls on servo motors, The existing motor and drive train are in GREAT shape so if I can get control of the speed I think it will work.
I'm spending other people's money
Mactec54
Re: VFD on a 25HP Rolling Mill
The one I did had servo motors for the rolled length. Not sure how it compared size-wise with the one you have.
It was Galil Based, like jim mentioned.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: VFD on a 25HP Rolling Mill
I will second using a Galil card to control the VFD. You are going to need a top end VFD with encoder feedback. I'd suggest looking up a fella that goes by MKJS on hobbymachinist.com for the correct model to buy.
Now the Galil programming language is arcane at best. Expect to hire help if this is not your cup of tea.
I LOVE a CNC interface, Camsoft, for your HMI. It is specially designed to work with Galil cards. Again, expect to hire help here if machine low level programing is not your cup of tea.
Re: VFD on a 25HP Rolling Mill
He does not need regular CNC control for this, or anything Galil, he would be better with a simple PLC, which will do everything he needs and have a lot less to do to get his project up and running
Mactec54
Re: VFD on a 25HP Rolling Mill
You are correct, the OP does not need a regular CNC control for this project. This project requires a purpose built, multi-axis, motion control solution and Galil products is the perfect hardware platform for the heart of this project. Karl_T likes the CamSoft interface software, I prefer to write my own interface software for custom controls. Either way, the flexibility of Galil products makes a project like this easy because they are a PLC and motion controller in one tidy package.
From the OP's description of the base machine, it would seem that this would require a 5? axis motion control system. Guessing here, but at least 4 servo motors for roll height adjustment, and one axis for the main drive. Very simple.
A simple PLC would be the more difficult solution in my opinion. Doable? Yes. With the correct modules.
Jim Dawson
Sandy, Oregon, USA
Re: VFD on a 25HP Rolling Mill
I'll just put in another plug for my favorite human machine interface - Camsoft.
It is not like any other control software. Super flexible design for all I/O and operator input, then write macros to run the galil as needed. In this case, i would not see using conventional G codes, probably write custom ones.
In fact, my biggest use of Camsoft is as the security and camera system for my home and business. It runs 24x7x52 to alert me in real time by cell phone or internet to a base computer anywhere in the world.
Do you need to use it? No. IMHO, almost no one has the ability to write your own interface like Jim does. If you can also do this, my hat is off to you.
Re: VFD on a 25HP Rolling Mill
I did the Camsoft school, and was a certified installer, using Galil, so know the system well, today it's just not worth the setup time to use there system, there are many good machine controls that are much more user friendly
Mactec54
Re: VFD on a 25HP Rolling Mill
I have used Galil and built a few systems going back to the DMC-1000 card. I really took to them.
The other similar card which in some way had the edge on Galil was the Acroloop card, One plasma company used them for their systems, the nice thing was it had some internal PLC's to handle the M/C M codes etc. as well as the CNC processor.
It always surprised me that Galil did not develop their own HMI etc, as Acroloop did, and left it to others such as Camsoft.
Here is the Innova Rolling M/C panel I put together using the Galil, the joysticks are for the optional manual operation.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: VFD on a 25HP Rolling Mill
BTW, I use a local Lamacoid engraving outfit to make up the reverse engraved panels for me from a DXF file.
The nice thing with reverse-engraved, the logo's or details can be filled in with any colour.
Also cannot be worn or filled in with grime etc due to the perfectly flat surface.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.
Re: VFD on a 25HP Rolling Mill
Sorry for the late response to all the good info being posted on my thread!
I was thinking over the weekend about how to control it, and using a PLC came to mind. I like the other suggestions as well.
I agree a conventional CNC may not be the best choice, and the same goes for a basic PLC.
There's a combination of things to control, both from a PLC and motion control perspective. Also the HMI, and how each job is programmed.
Based on the responses I will need to do some more homework on the control side and come up with a system diagram.
It should help to clarify the configuration of the machine, including the various inputs and outputs of the control system.
