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Milltronics MB24

Posted: Tue Jul 20, 2021 7:18 pm
by S-K Machine
Good evening gentlemen.
My name is Jeff and I own a automotive machine shop in new york.
We have acquired a Milltronics MB24 with a haas rotary that I am in the process of fixturing up to do engine block work.
The control on this machine is an antique. Even with the upgrade that the past owner did to convert the floppy drive to a card reader it is a royal pain.
I did fumble through it and made the riser block for the rotary and cut the slots in the angle plate with it. But it was painful.
It is time to upgrade!!!! I am going to purchase the all-in-1 dc and use the servo's over. I have the original schematics for the machine and compared them to the centroid .It is not too bad of a conversion, but is going to take a few weekends I'm sure to get it all ironed out and running.
I am hoping to use everything on the right side of the cabinet, including the transformer, the vfd and the contactors. Everything on the left will be gone.
Except in the middle is the 150V DC power supply with the 2 blue caps, that will stay.
I will change out the 24dc power supply to a fresh unit for piece of mind. This machine runs currently.
I have the computer picked out already. As far as touch screens, I see marty recommends the viewsonic and others have used the Planar PTC2235.
One is a single touch and the other a 10 point? I have never used a touch as a monitor so uncharted waters for me. Please enlighten me.
I am trying to gather as much parts and info before I break the machine down to start the transplant.

I am sure I will need some help from you guys. This forum is great.
I have been reading and reading to get ready!!.

Thanks in advance.
S-K Speed Racing Equipment

Re: Milltronics MB24

Posted: Wed Jul 21, 2021 9:43 am
by martyscncgarage
Have you watched my video series on All in One DC? You might find it helpful: viewtopic.php?f=64&t=2421

I believe the Milltronics DC Brush servos have encoders in them. You should inspect what you have. Make and model of the encoder in the end of the DC Servo housing. They likely also have Tachometers which will not be used with All in One DC.

Yes you can reuse the VFD, Brake etc. Don't know about the contactors, what is the coil voltage?
You might be able to reuse the DC Power supply, with the machine powered up read the DC voltage across the terminals of one of the large blue capacitors. They may be fed from that transformer which you would also leave if that is the case. What are the values on the capacitors. you may be able to reuse them.

I would take a video of this machine running all axis and then sell the PC/Acroloop motion control board as a unit and the individual drives to help recoup some of the cost of the retrofit.
See if you can put All in One in the place of the original PC/Control

ARE you capable of doing such a conversion? Have basic Electrical/Electronic skills and can follow an electrical schematic? Its not a quick trivial process, it could take someone that has never done it 50-80 hours. BUT in the end, if done well, it will be worth it!

You will also need a DC-1 for your 4th axis. It could be mounted to the cover of All in One DC if you have no other room elsewhere.


Re: Milltronics MB24

Posted: Wed Jul 21, 2021 7:18 pm
by S-K Machine
Thanks Marty.
Yes I have watched many of your videos.
Very helpful and full of information.
I am more than capable of rewiring the machine. I can read schematics, hell I have even printed circuit boards for past projects.
I know those DC motors have old encoders and tach's. The centroid kit I was looking at comes with the newer encoders.
Yes I also know I need the Dc-1 for the haas. I will probably buy a new encoder for that also.
The contactors should fly again ,as they use 24vdc everywhere in the system. I was going to put 2 fresh 24v dc power supply's in as they are cheap enough.1 for the contactors and another for the logic side of the board.
As far as the servo power supply with the 2 big caps, I can't see why they will not go again as they are proper for the motors currently.
They also have a rectifier circuit to go from 110vac to 90vdc for the z-brake that will stay.
I did list the entire Milltronics system on ebay already.

The question I had for you is why the choice of the viewsonic monitor? You mentioned 1 touch.I see that others have used the Planar PCT2235.
I am starting my parts list as I do like to have things on hand before diving in.

Thank you again for the quick reply.


Re: Milltronics MB24

Posted: Wed Jul 21, 2021 7:22 pm
by martyscncgarage
Kit? Which kit are you referring to?
I'd recommend a widescreen resistive touchscreen monitor. I'm not a fan of multipoint touch consumer grade monitors. I have personally witness phantom touches due to debris on the screen. Resistive touchscreens require a deliberate press.

Good luck with the project. Seems you are more than capable. Take photos along the way and document it.


Re: Milltronics MB24

Posted: Wed Jul 21, 2021 7:58 pm
by S-K Machine
Here is another question that I have after looking over the schematics.

They use a yaskawa vfd which I do have the pdf instructions for.
I see all of the connections to the all-in-1 except for pins 25,26,27 which they have labeled up to speed, zero speed and common.
Do we not need them anymore? And does the vfd need to be setup to ignore those terminals.
Here are the screen shots.
The other two area's that I am unsure of is the spindle has a low gear with an external roller lever switch.
That gets piped to the one of the logic terminals 1- 16 I am guessing?
And the other question would be controlling the Z-brake. In reading that looks like it goes to relay #9

The rest is pretty well straight forward.

Again many thanks to all on this forum.


Re: Milltronics MB24

Posted: Wed Jul 21, 2021 8:03 pm
by S-K Machine
Marty ...
The kit they have has the all-in-1,the power supply, and new servo cables with new encoders.

Re: Milltronics MB24

Posted: Wed Jul 21, 2021 8:19 pm
by martyscncgarage
S-K Machine wrote: Wed Jul 21, 2021 8:03 pm Marty ...
The kit they have has the all-in-1,the power supply, and new servo cables with new encoders.
Ha, I hadn't seen that one. Perfect!

Re: Milltronics MB24

Posted: Wed Jul 21, 2021 9:22 pm
by cncsnw
The spindle range-detect switch is usually wired to INP13.

You probably do not need the up-to-speed or zero-speed signals from the VFD, unless there is an automatic spindle brake on the head. If there is an automatic spindle brake, then it is helpful to have a zero-speed signal (wired to INP12) so you can hold off the brake until after the VFD has decelerated the spindle to a stop.

Yes, you use the OUT9 relay to control the Z axis brake release. Do not use the relay on the Allin1DC to switch 90VDC. Instead, either use it to switch the AC going into the rectifier that makes 90VDC, or use it to switch the coil of an external relay that in turn switches the 90VDC (preferably both legs, with a freewheel diode across the load side).

While the Centroid kit does come with pre-selected encoders, you might want to take a close look at the physical style of the encoders you have. They may turn out to be standard-dimension solid-shaft encoders, with either 1/4" or 6mm shafts. If so, you can replace them directly with encoders from Automation Direct. Of course, you then have to put your own plugs on the cables.... ... d-s2500-vd ... a-2e2500vd

Re: Milltronics MB24

Posted: Thu Jul 22, 2021 9:50 pm
by S-K Machine
Thank you Marc for a timely response.
Your knowledge and insights are appreciated and respected by all here.

So I was on the right track in thinking wire the spindle range to Input 13.Easy enough.
As far as the Z-Brake, yes I was going to leave the circuit they have in place, diode and all, and just switch the 110vac on Output 9.
It looked like those relays should handle the amperage. I am not sure how much current the brake draws. I have an amp probe ,easy to measure.

I did peak inside the cabinet before I went home and did see 2 smaller gauge wires going to the spindle motor in the conduit.
I am not sure if it is a spindle brake of a spindle fan. I will trace it out soon. They do have wires going up to speed and zero speed connected in the vfd.
So they are using the logic from those signals. I will investigate some more before I tear it apart. I need to measure and log a few things before disassembly as it currently runs.

And yes, next thing to look at is pop the back of the motors off and see what I am up against inside there. The Z says MT30U4-42 and the others are MT30U4-29.I am sure I will be making some sort of adapter or coupler.

Again thank you very much.
I am looking forward to bringing this machine into the 21st century.

S-K Speed

Re: Milltronics MB24

Posted: Fri Jul 23, 2021 7:04 pm
by S-K Machine
Marc was spot on once again.

I took the servo cap off today and these encoders have shafts not thru-holes.
They seem to measure 6mm on the shaft size.
Marc the encoders you mentioned here are of good quality? What I mean is the same as what centroid offers or it doesn't mean that much.
Do I change out the couplers also, or just keep what is there right now.
If I buy the servo wiring cable pre-terminated from centroid, will they give me connector and pins for the encoder?
Or is that something I have to source from mouser or digikey.

I'm getting closer with my shopping list.
I can't wait to start converting this machine.

Thanks everyone again.