Hello Guest it is October 21, 2021, 04:07:12 AM

Author Topic: Retrofit Recommendations for Sharp CNC Knee Mill Using Existing Components  (Read 3730 times)

0 Members and 1 Guest are viewing this topic.


I just picked up a Sharp CNC knee mill (Sharp HCV) with a Mitutoyo Millstar CNC control with Mitutoyo linear scales on X, Y and on the quill. I don’t know what generation of Millstar this is. 1, 2 or 3? Anybody? Anybody have manuals and documentation for the control?

The Millstar controller is an old Pentium S PC with a Galil DMC-1020 motion card, a whopping 4 megabytes of RAM in a case with monitor, does power on, but there’s a problem with the IDE drive failing to boot. Bad IDE hard drive would be my guess.
The PC has PCI (but I think no PCIe) slots.

It has Glentek brushed DC servo drives for X and Y axes and I'd like to keep/use them if I can.
I'd also like to keep/use the Mitutoyo linear scales.
Recommendations on hardware to get to adapt/use the existing Glentek drives and Mitutoyo scales with Mach 3?

Also, they replaced the head with a 3HP Gromax variable speed head. I don’t know anything about Gromax. Anybody have manuals they can share?

My kids have been helping me clean off some of the grit and dirt and rust with Scotchbrite and WD-40. The Y axis definitely shows some wear and a bit of scoring on the ways, but the overall machine is pretty solid.

Anyone have manuals for the Sharp mill?
Docs for Mitutoyo Millstar?
Docs for Gromax 3HP variable speed head?
Recommendations for way oil? Spindle oil? ...
Anybody have a Millstar hard drive that I could clone?

Is it worth it to try to resurrect the Millstar controller?

Or, would it be better/faster/easier/cheaper to try to convert it to Mach 3 CNC?
How to use the existing Glentek brushed DC servo drives with Mach 3? I'm guessing they take 0-10V input, but not sure.
How to use the existing Mitutoyo linear scales with Mach 3 CNC?
Mach3 and in fact Mach4 are native step/direction controllers. They can with suitable motion cards be used to drive analogue servo drives. The motion card usually completes the loop. I would
suspect that is what the Galil card does. Galil is a very good brand but expensive, if you can reuse it by all means do, I suspect you wont buy a new one no matter how good they are.

Another possibility is to use the step/direction output from Mach/controller to step/direction input DC servo drives with your existing servos. Gecko 320s have as good rep as do CNCdrives servo drives.

DC servos are yesterdays technology, if you have to start to replace components, particularly if you have to mix and match between manufacturers it can become expensive really quick. The combination
becomes vunerable to obsolescence.You might consider AC servos and matching drives. Delta is a trusted Twainese brand and about $500 for a 750W AC servo and drive which will outperform any DC servo of the
same power. The resolution and control solutions of a modern AC servo so far exceed anything that was ever even attempted with DC servos and AC servos are now cheaper as well!

I would suspect that the Mitutoyo scales are separate to the CNC control. Can you provide some pcs and model numbers? If they are separate or could be made so that would be easy. Some people like the idea
of trying to incorporate them into a closed loop control setup. I have no doubt its possible but if you can do it I suspect JPL and /or NASA will be wanting to hire you. If that's the case play with their mill! LOL

Don't know anything about the spindle motor. Most probably an asynchronous AC motor. May I suggest work out how to control the axes first...see whats possible and within your budget and THEN start getting
serious with the spindle motor.

My wife left with my best friend...
     and I miss him!
The pictures in the link I posted show the scale (Mitutoyo models AT-102 and AT-111) and you can see one of the brushed DC servo motors.
First, I'd like to see if I can resurrect the Mitutoyo Millstar CNC control.  The computer appears to work, but since I can't get it to boot, I can't really check it out.  I've never used a Millstar, so I don't know what the GUI is like or how easy/hard it is to use.

However, I do want something reliable and good.
Brushless (AC) servo sounds nice, but that'll run a lot of money unless I can score a good deal.
I thought about using Geckodrives.

I'm just looking for manual/docs for things for completeness.  I don't think there's anything wrong with the Gromax head or anything.
by far and away the cheapest alternative is to use the Galil and existing servos and drives.

If you find you need to replace the drives you are in the territory where replacement with a DC drive like
a Gecko looks cheapest but you are adding a layer of complexity which may mean that the apparently
more expensive option, AC servos, actually works out cheaper, they are a buy once and use for decades
type solution.

If you wish to resurrect the existing controller you will need Mitutoyo support, and what's the bet they say it obsolete.
It becomes not a project in Mach or even CNC but a vintage electronics restoration project.

My guess is that the linear scales are free standing.

« Last Edit: May 23, 2018, 08:42:22 PM by joeaverage »
My wife left with my best friend...
     and I miss him!
I think the first step in resurrecting the Mitutoyo Millstar CNC control is for me to clone someone else’s disk, since this one doesn’t look it it wants to boot.
When I look at the BIOS screen, it doesn’t show the hard drive, even though I hear it spin up.
Although I’m not sure how many different motion control boards, sero drives, encoders, ... they used or if they stuck with the Galil DMC 1020/10x0 series, Glentek, ...
Then I’ll need tuning and other parameters, so maybe it will be a lot of work to try to get an old control working.
this forum is dedicated to Mach CNC software. It seems unlikely then that this forum will provide much information about a Mitutoyo control.

CNCZone has a wide readership on a very diverse range of equipment and may produce results for you.
Have you emailed Mitutoyo?

My wife left with my best friend...
     and I miss him!
Yes, I’ve already emailed them.
I’m also planning on the strong possibility that I won’t be able to get the Mitutoyo control going, in which case I’ll be trying to retrofit it with Mach 3.
if your thinking that a Mach retrofit is the way to go may I suggest getting as much information about the Galil board you have, my guess is that you will be able to interface Mach
to the Galil and the Galil will close the control loop of your servo amps and servos.

Galil are still very much in business and would also guess that theres plenty of info about your board.

My wife left with my best friend...
     and I miss him!
saw this:

Controller   Introduced   Estimated End-of-Life   New Equivalent
DMC-1010 - DMC-1040   October 1992   1 to 2 years   DMC-18x6

So despite the Galils age its still current just! If I read the model interpretation correctly it sounds like a
two axis controller.

My wife left with my best friend...
     and I miss him!

DMC-1020.........................2-axis ISA......

You'll need ISA slots...starting to look pretty dated and you still need another axis. A two axis controller
would give you 2.5D capability at best.

Would you post the details off your existing servos, preferably either a power rating or torque/speed, something,
anything to work out what power they are. Looking at the dated controller I'm thinking you should look really closely
at what you can do for a given sum in the AC servo field. DMM for instance do 200 and 400W units for $200-300.

Mach3 is $175 or Mach4 for $200. A Ethernet SmoothStepper (my choice) is $185 running on a Latte Panda
board, $150 including Windows 10 Enterprise. That combination will kick ANUS! Whats more it will do so for years
and years to come and have the capability to grow and expand as you become more demanding.

My wife left with my best friend...
     and I miss him!