questions about Hurco CNC-MB-1

[Strange179]

I'm not going to post all my pictures on the board because they're all really big and it's easier for me to just host them on my own server. Here's the link http://jdm.hopto.org/hurco/gallery.html

Voltage issues update:
I think my DVOM is NFG. Or at least it doesn't work for AC measurement. I couldn't get a reliable reading at all yesterday. I did find that the fuses in the disconnect switch for the step-up transformer were bad. I think that at least one of them was bad before and now they're all bad. I'm going to replace them and see what happens at that point. All the fuses I tested inside the Hurco's panels seem to be good.

In reading the schematics I believe I'm right in thinking this MB-1 can somehow be wired directly to the 230V lines. The schematics do indeed show the incoming power going through the disconnect, the fuses and then directly through T3, a voltage reducing transformer that steps down the voltage to 230V. I believe that T3 has been replaced at some point in the machine's life and I'm not sure if the current transformer (a Square D model) will be able to be wired in a way that will allow me to run 230V through it. I may have to bypass it completely.

Justin

[Strange179]

I got the machine a little closer to running today. I did as I figured I could and bypassed the step-up and step-down transformers and supplied the 230V directly to the machine. The Z axis is now working as it should. The CRT still won't display correctly and it seems I've got some sort of tach signal issue. it was spinning and I turned the knob for speed override, it sped up and then said No RPM on the screen. Now it seems that whenever I try to activate the spindle it moves less than a full rotation and gives me the same error. The tool changer also threw errors 64 and eighty something when I tried to change a tool.

I wish I had an oscilloscope and I wish I had a fully working DVOM. I've gotta sort out that CRT issue. Once I get the machine in working order then I can look at upgrading things.

Justin

[Mike Stevenson]

I have experience with the machine you speak of. The control did not have round DIN conectors in the back. WE were able to load the master by means of an rs-232 adapter board that plugged into the card cage behind the service door in the back. The machine will ONLY program using the Hurco conversational method. G-code is not an option. Take my advice and forget about this boat anchor. They are obsolete and more trouble than they are worth.

[thebodger@roger]

I have about 20 years experience as a seviceman on these MB1 machines. They have their positive and negative issues, too many to list. As for as running them on 220 volt single phase, it is possible, EXCEPT the spindle drive, which needs 3 phase. And that 3 phase chopper for the spindle motor is long obsolete, and never really worked well.

[Strange179]

Originally Posted by thebodger@roger I have about 20 years experience as a seviceman on these MB1 machines. They have their positive and negative issues, too many to list. As for as running them on 220 volt single phase, it is possible, EXCEPT the spindle drive, which needs 3 phase. And that 3 phase chopper for the spindle motor is long obsolete, and never really worked well.

I'm not trying to run the machine on single phase. I have actual 230V, 3 phase power available and now wired to the machine. I bypassed the external step up and side mounted step down transformers and wired it direct to the 230 supply. You do, however, make me wonder if the polarity of the three phases might make a difference. I don't believe they do but I could be wrong as my 3 phase experience isn't as extensive as my single phase experience.

I'm not sure what you mean about a 3 phase chopper. Are you referring to the parajust spindle speed control?

I haven't had much time to work on the machine in the past month or so but the project is still active. Any information is greatly appreciated.

Justin

[thebodger@roger]

Yes I was refering to the parajust spindle control, needing 3 phase 220 volt. As far a polarity is concerned, it would only matter if this mill has a coolant pump, in which case if the polarity was wrong the pump would run backwards. Simply reverse any 2 leads on the incoming 3 phase supply will cause the motor to rotate in the proper direction.

[Strange179]

Originally Posted by thebodger@roger Yes I was refering to the parajust spindle control, needing 3 phase 220 volt. As far a polarity is concerned, it would only matter if this mill has a coolant pump, in which case if the polarity was wrong the pump would run backwards. Simply reverse any 2 leads on the incoming 3 phase supply will cause the motor to rotate in the proper direction.

Thanks for the quick reply. The 3 phase coolant pump seems to be long gone and has been replaced by a small 120v model.

So, from what you say it seems that I shouldn't be having any problems due to the simple 230v 3 phase hookup. I was concerned about that a little bit.

Do you have any idea what might be causing the spindle problem I seem to have developed? It starts to rotate but moves only a partial rotation and stops with an error on the display. I think the error was "no rotation" but I'm not sure at this point since I'm not in front of the machine.

Thanks,
Justin

[thebodger@roger]

Can you start the spindle manually? To do this press the "enter" button, then "operate" then spindle "on" then "start". Press the "start" button rapidly several times to ensure that all the relays latch. If you still get the "no RPM" error then it can be several things, Usually it's a bad contact in one of the relays in the cabinet where the servo drives are, or there are 2 or 3 small relays at the bottom of the parajust drive. I can't recall off hand what the relay is call for spindle start, I'll need to look it up , and get back to you on that.

[Alzeric]

Oye I wish I came here long ago.

My company allso had an old MB-1 sitting collecting dust. Nobody seemed to know how the thing worked and wouldnt go near it.

As a Machine operator (not a machinist) I decided to crack my knuckels on it. It took me a few years of scrubing, tinkering and electronics hell but I got the beast to run! Few weeks later I even have runs of succesful parts under my belt (yea me) and the company is happy.

To me it's really impressive I can make 100 mounting plates and every piece be the same. But so far I have only done simple simon jobs. Some minor loops, hole patterns, slots and fixurs. Some questions I have came upon to ask of the Hurco vets...

Any time I try to face anything more then 2" wide the spindle jams. even if I'm only cutting .005 off. If I go over 3" wide I cant even face off .002 of aluminum. Yet I have the power to drill a 5/8 hole thru 1" thick steel like it was nothing. I have both a 3" and 3.25" cutters. Is it common for Hurcos to lose horsepower when working with tool Dia over 1"? This leads me to next question.

All the tooling I was able to find for the Hurco was rather small. The biggest shaft I can fit is a 5/8. I had to make my own fittings for anything bigger. The toolings are not like any others I have ever seen and can not find any and I fear I am stuck with the few I have. This makes it a bit of a issue as I now spend more time trying to get mills and drills to fit my tooling then it does to program and run the jobs themselvs. They are much smaller then the Mazak ones with 2 little nubs on the side.

Any time the power flickers, or the compresser overheats the Hurco autoshuts down and I have to re-zero my table. Has anyone ever setup a UPS to keep the settings?

the number pad sticks alot and makes it very hard to program. I have not found any replacment boards and its one spot I worry about taking it apart to fiddle with. any suggestions?

I'll have much more to ask as time grows but its late and this is plenty for now.