CNC Knee Mill Control Conversion

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Marty_Escarcega
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CNC Knee Mill Control Conversion

Postby Marty_Escarcega » Mon May 22, 2017 8:20 am

Hi Guys,
I've been pretty busy for the last year. Lots going on....
Last few months I have been working on a CNC Knee mill I acquired a few years ago. It was in remarkable condition. It came with a Mitutoyo Millstar III control. Mitutoyo USA fitted the controls here. It used an SBC (single board computer) with Pentium processor, running Windows 95. It used off the shelf Glentek servo amplifiers and Glentek servo motors. The software was not upgradeable, it was somewhat Gcode compliant but not completely and quirky.

SO, I made the decision to convert it. I DID NOT want to use Mach 3. That would be going backwards. I had used Flashcut CNC on a small VMC (verticle machining center) conversion which worked well but not a totally closed loop system and for what it was, it was expensive. SO, I chose Centroid CNC All in One DC module, it has a motion controller, PLC (progammable logic controller) and 3 DC brush servo amplifiers built in to the All in One DC. It communicates to a standard Windows PC with a 2.9ghz or faster processor via an Ethernet port with a SHIELDE ethernet cable.

Centroid has been around a very long time and makes a great control. The same software runs their 5 axis engine VMC, which machines engine blocks and can custom machine cylinder heads. You can check out their YouTube channel CentroidCNC [youtube]https://www.youtube.com/user/CentroidCNC[/youtube]
They have examples of their machines and explain the All in Once DC as well as some tutorials.

Anyway, because this is a true closed loop system, and I felt there would be good support, I chose them. This system is much better and much more friendly than the Millstar control which no longer had software support Because the machine was in such great little used shape, I decided to spend the money on the All in One DC board (about $2500). I think it really helps the value of the mill too.

I have been documenting my process on my YouTube channel, martyscncgarage https://www.youtube.com/channel/UCTNt9IIjsk5HNwnjzer6GVQ
If you care to follow along. I am in the homestretch. Machine is now moving under the control. I thought it would be good to "document" the process for others that might be thinking about doing the same.

Marty
"Jack of all Trades, Master of None"

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GlennW
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Re: CNC Knee Mill Control Conversion

Postby GlennW » Mon May 22, 2017 8:45 am

I'll tune in!

Thanks Marty
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

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SteveHGraham
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Re: CNC Knee Mill Control Conversion

Postby SteveHGraham » Mon May 22, 2017 12:02 pm

Mainly, I thank you for the Youtube channel. I will definitely watch.
Don't trigger me, bro!

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Re: CNC Knee Mill Control Conversion

Postby rrnut-2 » Mon May 22, 2017 1:10 pm

Marty, thank you for the input on the Centroid CNC. Mike (RRSC) and I were looking at this for a Bridgeport conversion.
But, he bought a late '70,s Bridgeport Interact I for cheap and the machine hadn't seen much use. I currently building a
new control system for it using Delta Servos, Vital DSPMC/IP motion controller and of course, a touch screen Industrial PC
running Mach 4.

Jim B

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Marty_Escarcega
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Re: CNC Knee Mill Control Conversion

Postby Marty_Escarcega » Mon May 22, 2017 2:53 pm

rrnut-2 wrote:Marty, thank you for the input on the Centroid CNC. Mike (RRSC) and I were looking at this for a Bridgeport conversion.
But, he bought a late '70,s Bridgeport Interact I for cheap and the machine hadn't seen much use. I currently building a
new control system for it using Delta Servos, Vital DSPMC/IP motion controller and of course, a touch screen Industrial PC
running Mach 4.

Jim B


For large machines, I will not use Mach 3 or 4.

I think when you look at it, the Centroid All in One DC (TRUE motion controller, PLC and 3 DC Brush Servo Amps built in) and their proven well supported software is a bargain at $2500. Of course, there are nickle and dime costs. You can reuse most DC brush servos and if they don't have encoders on them, you would have to upgrade the encoders. They also have good tech support. For the $2500 cost you get a couple hours of remote support, where they will come in remotely to the CNC PC and help configure the software. Sometimes they can remotely tune the servos. This was just done on my machine today. Took him less than 30 minutes. I did have fairly common Glentek servos.

The AIO DC also has inputs for standard MPG's and true spindle encoders. Flexibility to expand if needed, including support for tool changers.
I will be doing my Emcoturn 240 turning center next. There is A LOT to be said when the hardware AND software come from the same company. No finger pointing, other than the user who does the conversion. Wiring and configuration are your responsibility, but Centroid provides a good install manual and many installation schematic examples. I tried to do videos showing every step following the manual. So far so good!

Do keep us posted on your progress Jim, I do wish you the best of luck.
Marty
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SteveHGraham
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Re: CNC Knee Mill Control Conversion

Postby SteveHGraham » Mon May 22, 2017 3:17 pm

I wonder if it's time for a sticky topic for great Youtube channels. Keith Fenner now has a list on his "About" page. It's like he copied my subscriptions.
Don't trigger me, bro!

rrnut-2
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Re: CNC Knee Mill Control Conversion

Postby rrnut-2 » Mon May 22, 2017 3:52 pm

The motors were part of the decision, no encoders and lots of machine work to add them. So this machine is getting new
servo motors. As far as the spindle is concerned, I am using a vfd. The machine has a varispeed drive, so putting an
encoder on for threading would be a challenge.

Youtube would be great, but I am not very good at recording what I am doing other then doing schematics.

Jim B

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Marty_Escarcega
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Re: CNC Knee Mill Control Conversion

Postby Marty_Escarcega » Mon May 22, 2017 4:26 pm

My motors had tachometers. Fortunately they were fairly easy to remove and replace with encoders.
I am not putting an encoder on my spindle at this time. It's pretty difficult to do on a Bridgeport type head. I too have a VFD. Easily controlled by the Centroid all In One DC.
Pictures here would be good along with your progress. Truth be told, it's A LOT of work to edit and upload them. But it's also a way for me to give back to the YouTube Community. I've learned and continue to learn a lot and get ideas from other's videos.
Marty
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Re: CNC Knee Mill Control Conversion

Postby Marty_Escarcega » Mon May 22, 2017 5:28 pm

By the way, if the motors you got are AC servos and Amplifiers, then Centroid OAK board might have been a good alternative (depending on communications to the amplifiers). It is less expensive than the All in One DC because the amplifiers are not needed.
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Re: CNC Knee Mill Control Conversion

Postby Dave_C » Tue May 23, 2017 8:13 am

Marty,

I'm a big fan of the Centroid CNC stuff as well. I don't own any of it yet but I've been watching their product and videos for the last 8 years or so. I get the same feeling about dealing with one company who has both the software and the hardware.

I don't have a machine worthy of putting Centroid hardware on right now, but maybe someday..I'm looking at a Grizzly G0678 as a possible conversion but still, it will be a Mach 3 conversion with closed loop steppers. (Feedback encoders to the stepper controller but not to the motion control software) At least it can't miss a step and keep running.

I'd say you made a good decision!

Dave C.
I learn something new every day! Problem is I forget two.

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Re: CNC Knee Mill Control Conversion

Postby Marty_Escarcega » Tue May 23, 2017 8:23 am

Dave_C wrote:Marty,

I'm a big fan of the Centroid CNC stuff as well. I don't own any of it yet but I've been watching their product and videos for the last 8 years or so. I get the same feeling about dealing with one company who has both the software and the hardware.

I don't have a machine worthy of putting Centroid hardware on right now, but maybe someday..I'm looking at a Grizzly G0678 as a possible conversion but still, it will be a Mach 3 conversion with closed loop steppers. (Feedback encoders to the stepper controller but not to the motion control software) At least it can't miss a step and keep running.

I'd say you made a good decision!

Dave C.


Dave, you will be pleased to know that Centroid is entering the stepper control market. You will also be pleased to know that the introductory target price for the board AND software is WELL within the reach of the hobbyist and educational institutions if all goes according to plan. I happen to know someone who is beta testing them at this time. :wink:

It uses the same software as their industrial controls. Anyone tired of Mach3 controlled system will be able to easily switch over provided they have a PC meeting the system requirements of the software which is basically a Celeron processor or higher running 2.9ghz or greater. A touch screen monitor will be HIGHLY recommended! but not required. The lathe guys are really going to like this board too. Once you get a taste you won't ever go back to your other control software. 8)

You can find out some details by dropping in on the AJAX forum on CNCZONE.COM. Search for ACORN. Let us know what you think after you have taken the time to read up on it. :)

Marty
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rrnut-2
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Re: CNC Knee Mill Control Conversion

Postby rrnut-2 » Tue May 23, 2017 11:43 am

Marty, I looked at the Oaks board, too bad that I am so far into what I am using now. The next machine will be with the Centroid. I like the fact that the cables are already made for Yaskawa and Delta drives.

Jim B


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