Hello Guest it is July 08, 2020, 06:54:04 AM

Author Topic: Hoping to retrofit a CNC mill with Mach3. Where do I start?  (Read 21966 times)

0 Members and 1 Guest are viewing this topic.

I'm sure there have been a number of these threads in this forum.  I did a search, but the results weren't exactly what I needed to send me in the right direction.  I have an old Tree Journeyman 330 CNC knee mill that still has the original control.  I've never even been able to make any parts as the control seems to be in a constant state of disrepair.  The latest battle involves the power supply.  Instead of paying someone $800 to troubleshoot and replace $2.00 in parts, I've decided to look into a retrofit.

Anyway, the machine I have is a pretty solid piece of iron.  Everything on it is original and in good condition (control notwithstanding).  I am wondering if it would be possible to toss the old control and run the machine with Mach3.  My main interest is in reliability.  I am not worried about super-fast rapids or elaborate 4-axis movements.  The parts that I plan to make will be very simple.  The idea would be to use the machine to make a little money and eventually upgrade to a VMC.

I am hoping that someone can get me started in the right direction as I look for information about a retrofit.  I know virtually nothing about the intricacies of such an undertaking, but I am willing to learn.  I do have a few questions that probably have simple answers.  The machine has a two-speed geared head.  Would I be able to utilize this feature with Mach3?  Would I be able to keep the DC servos and drives?  How about the spindle drive?  Are those usually replaced in such a situation?

Well, I am hoping that I will be able to get this machine up and running.  I've pretty much given up hope on the original control.  Even when it's running properly, it leaves a LOT to be desired.  The machine is fantastic, but the electronics need to be put out to pasture.  Thank you for taking time to read my post!

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #1 on: May 28, 2009, 05:04:10 PM »
If you want to keep the old drives then it is likely they are analogue input (+-10v) so you would need to use something like
 DSPMC   http://www.vitalsystem.com/web/motion/dspmc.php
 Galil        http://www.galilmc.com/
 K-Motion http://www.dynomotion.com/Kanalog.html
all of these are external controllers that interface to Mach via a plugin and prices start around $500 upwards I think.
 There is also
 YAPSC. http://max-mod-shop.com/index.php?option=com_content&view=article&id=47:yapsc10v&catid=17:-yapsc&Itemid=4
This takes step and direction from Mach via the parallel port and converts it to analogue.

I have no experience with any of the above so cant comment.


Depending on your servos voltage and current you may be able to use some of the drives that can accept Step/Dir signals directly, some of them are
Geckos    http://www.geckodrive.com/
Tek10     http://cncteknix.com/portal/index.php
Rutex      http://www.rutex.com/us/index.php
Viper       http://www.viperservo.com/


Gearbox should not be a problem, depends really how it works at the moment.

Spindle drive also will depend how it works, ie is it a VFD or is it a DC Servo or AC Servo etc.

Hood
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #2 on: May 29, 2009, 01:08:13 AM »
Thank you for the info.  Hopefully, I can continue to read through some of the posts and glean some vital information.  Is there a better place for newbies such as myself that know virtually nothing about conversions?  As I mentioned, I'm willing to learn and actually like to figure out stuff that challenges me.  I know that successfully retrofitting this mill certainly be very fulfilling.  However, I have the feeling that there is also a large possibility for frustration and disappointment.

Anyway, the machine I've got has Gettys N360 drives and Gould DC servos.  I have quite a bit of documentation and schematics for the drives.  However, most of it is information that I don't understand (yet).  The upside is that, should I be able to use them for a retrofit, I should have any information necessary for wiring them up to new components.  There is also some information for the inner workings of the servos, but I'm not sure if there was anything pertaining to encoders.

The spindle drive on the machine is a Fanuc AC drive.  I have no idea whether or not it could be wired into a retrofit system.  It looks like a pretty substantial piece of equipment.  I have schematics that detail how it is tied into the current control.  So, like the servo drives, I should have any info necessary to wire it up (should I be able to utilize it).

Well, thanks again for the links to the equipment.  I will certainly have to learn more about what I'm doing before I start purchasing equipment.  I have the feeling that, once I learn a little more about retrofits, I won't be so intimidated by the process.  The current control is a mind-boggling mess of wires that run in every direction.  Fortunately, most (but not all) of it is clearly labeled and organized.  I only hope that any attempt I make to retrofit will allow this machine to start making chips again.  It's a damned nice machine that is very capable of doing quality work.  I just need it to run!  If anyone can give me some more pointers on where to start learning, please let me know.  Thanks!

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #3 on: May 29, 2009, 02:13:58 AM »
If you attach the docs for the driveS, motors etc maybe we can help a bit more.
Hood
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #4 on: May 29, 2009, 03:58:29 AM »
The drawings/diagrams/schematics for the drives are all on 8.5x11 sheets of paper, but the others are quite large.  So, those probably won't be scanned any time soon.  The info that I've read thus far has led me to conclude that I should just dump original servo drives.  I have read numerous good things about the Granite drives, but I'm not sure if they will work with my servos (still more reading to do).  Since the spindle motor is AC, I guess it would also be wise to think about controlling it with a VFD.  I am not trying to keep this machine on the lowest budget possible.  It will be helping me to earn a living, so I don't mind investing in it.  However, I'm certainly not about to drop $15K on something like a Centroid.  It sounds like some learning and determination allow most people to put together a great CNC system.

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #5 on: May 29, 2009, 04:11:40 AM »
The spindle you say its a Fanuc AC, I was thinking you were meaning an AC Servo, is that the case? Or is it a normal AC induction motor?

As for the drives, if it was me I think I would be looking at the DSPMC, as said I have no experience of them but most I have seen has been good and if your drives are good then it may actually be cheaper than getting new drives, then again thats all things you have to weigh up. I would imagine your servo motors will be 140 to 190v DC, if thats the case then any of the normal drives such as Granite, Gecko etc will reduce your rapids capability as I think they are all around 80v max
Hood
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #6 on: May 29, 2009, 05:01:03 AM »
The spindle you say its a Fanuc AC, I was thinking you were meaning an AC Servo, is that the case? Or is it a normal AC induction motor?


To be perfectly  honest, I'm not even 100% sure.  It just said "Fanuc AC Spindle Drive" in the literature that I was reading.  The machine has never had rigid tapping capabilities (usually indicates a servo motor at work, right?).  It's an old mill (1984).  I'll have to take a closer look to see if I can get a definite answer to this question.

As for the DC servos and drives...  I will go through the paperwork again and see if I can find some pertinent numbers.  Do most older DC servos run at such high voltage?  I don't mind if I lose a little rapid speed.  This mill doesn't even have a tool changer, so fast rapids are kind of pointless, anyway.  Rigidity, reliability, and reasonable accuracy are the only things I would be after.

Offline Hood

*
  •  25,846 25,846
  • Carnoustie, Scotland
    • View Profile
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #7 on: May 29, 2009, 05:23:43 AM »
You will soon low if you look at the motor, servos look totally different and AC variety are usually square. An induction motor will look just like any other motor you would see on a saw or a compressor etc. If you can take pics that would help. As for it not being a servo becazuse no rigid tapping then thats not nesecarily the case as it could be the control is not capable of rigid tapping. Mach is not capable normally but it can be done by some trickery.

Usually machines of that vintage will have high volt DC motors or certainly all the ones I have seen have. If your motors are say 160V and you use a drive that can only put out 80v then your rapids will be approx half of what they were before.
Hood

vmax549

*
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #8 on: May 29, 2009, 09:17:54 AM »
THere is another option with using your old drives, take a look at dynomotion motion controller it has analog built in as well AND there is a MACH plugin. I believe it also has function for a servo spindle in case it is. It may be able to handle the resolvers as well(;-) 

I would spend the time to call TOM @dynomotion and talk with him about it also.

It really is HARD to make a general statment concerning a specific setup without seeing the specifics  first.

Just a thought.  (;-) TP
Re: Hoping to retrofit a CNC mill with Mach3. Where do I start?
« Reply #9 on: June 04, 2009, 07:27:56 PM »
Thank you for offering some input into this thread.  I would like to start rounding up all the necessary equipment for doing this retrofit.  I would like to replace as much as possible, so the old servo drives are sure to go.  It would probably be good to replace the spindle drive, as well.  However, I am not sure how easy that will be to do.  I still need to take a closer look at everything that is there and see what all needs to go.  Ideally, I would like to keep all the motors and get rid of all the drives. Although I know very little about retrofits, that seems like it would be the easiest route (if possible).

Anyway, I was hoping to compile a list of the larger components that will be absolutely necessary for this retrofit.  The PC and software will be easy.  I will need at least three drives (one for each axis) and a "breakout board," correct?  Should I just make a decision and just buy some?  I am still leaning heavily toward the Granite drives.  I don't mind that they cost a bit more than some of the others.  For this retrofit, I don't mind spending an extra one or two thousand dollars to make sure it is done right and results in a machine that I can depend on.  I have no plans to pinch pennies.

I will try to get more specific information (voltages, motors, etc...) and post again.  Thank you for the help thus far.  Hopefully, I will be able to find my way and get this machine sorted out.  I'm sure this forum will be instrumental in any success I manage to find.