Need Help!- South Bend Magnaturn Blade Switch

[R_Huse]

I have a South Bend Magnaturn lathe that suddenly developed a problem. While running a program, the machine suddenly stopped and the error "X axis servo fault" came up on the display.

I shut down the machine and restarted it, thus rebooting the computer. On boot up, the computer goes through the normal diagnostics and then hangs displayined the words "checking X axis blade switch".

Since this is happening on boot, I would assume this does not mean a hydraulic servo switch but rather something on the X axis controller boards. I may be wrong on this though and perhaps the computer does do some sort of check on the hydraulic control system as well.

Opinions? Might it be a switch in the hydraulic system?

[sexton]

Did you figure out the problem with your x-axis fault?

I have a Magnaturn that I bought a while back and need to run it on a
phase convertor. Are you using a convertor?

Also aside from the x-axis fault how do you like the Magnaturn?

Kinda sounds like 20 Questions, Huh.

David.

[R_Huse]

>Did you figure out the problem with your x-axis fault?

Yes I did. The problem was that no where on the plans for the lather could I see someting that indicated it was a "blade switch". I later found out through a friend that the "blade switch" is referring to a switch on the stepper motors. He suggested I switch the x axis stepper control card with any of the other four stepper control cards since they are all identical.

I tried this, switching x for z as it seemed the easiest. The fault indicated on the diagnostics then indicated the z axis blade switch rather than the x. This told me that the fault was actually in the board rather than the blade switch as diagnostics indicated.

I then looked carefully at how the stepper control cards were mounted. The appeared to be mounted to a really large heat sink, indicating to me that the 5 L165 Op Amps get really hot. Generally if I am diagnosing an electrical issue, I generally tend to suspect the thing that gets really hot will be the first to fail, so, I suspected one of the L165's was faulty. I also found there was a fan mounted behind the heat sink that did not appear on the plane. Upon turning that I found is was pretty squeaky. I therefore decided to replace the L165's and the fan. I replaced all op amps rather than trying to diagnose which one was to blame, as they were $5 each, so for $25 I could replace all and the time savings seemed worth it to me.

I replaced all op amps on the stepper board and replaced the fan. I then poured a martini, and fired up the lathe.

Sucess, the martini was just perfect, I prefer a twist of lime rather than an olvie, and it tasted really good. The lathe fired right up as well, so that was good too.

>I have a Magnaturn that I bought a while back and need to run it on a
phase convertor. Are you using a convertor?


Yes. I had run this lathe on three phase power originally, but when I moved my shop I found the power company had jacked the rates up for three phase conversion so high that I didnt want to pay it. I felt the money could better be spent on more martini fixin's.

I use an American Rotery phase converter as frankly they seem to be built a hell of a lot better than the phase-a-matics. I also have one of those.

Incidently, the Magnaturn is a 15HP machine. Most phase converter people will tell you that you will need a 15HP phase converter to run this lathe, unless you need to do instand reverse, primaraly for threading. If this is the case they will recommend a 30HP phase converter. Thats what I bought.

However, about a month after I bought it it occured to me that the Magnaturn is a hydraulically operated lathe. This makes a big difference, because to switch rotation you are not actually reversing the spindle motor, but simply switching an hydraulic valve. To me it would seem that therefore there is no additional load, so one should be able to run a 15HP phase converter and save quite a bit of money.

I run the Magnaturn on a dedicated phase converter. I would advise this. Frankly I get a little worried about running one big giant phase converter and pulling everthing in the shop from it, especially with CNC equipment.

Again, I would highly recommend the American rotery converter for the lathe, Bombay Sapphire for the martini.

>Also aside from the x-axis fault how do you like the Magnaturn?

I like it a lot actually. It does quite a bit for a lathe in its size range. Do I wish it had live tooling? Sure. Do I wish getting programs into it did not require me to use floppys and rewrite the Sys.Dir on the floppy every time? Yes. That aside I like it a lot and the Ultrapath programming system is actually very good provided one does not have to do pocketing. If you are unfamilier with what I mean by this, ask me as its fairly important and you will do incure tool damage if you try and use ultrapath to do pocketing.

My only concern with this lathe is the age and the fact that it is an orphan since South Bend went belly up. The people there were amazingly helpfull with any issues I had and since the parts department has been sold to LeBlonde its not at all the same. If you run into a problem, LeBlonde will be able to get you a part but youd better know what you need and the part number. They didnt make the lathe so I guess they can be excused, however it would have been nice if LeBlonde had hired some of the South Bend people who knew something about this lathe. Apparently that was not to be as I heard the break up of this division of south Bend was less than pleasant.

[sexton]

Thanks for the info on the Magnaturn, and the martini. I'm sure I will have more questions once I get my lathe running, if you don't mind?

David

[R_Huse]

Sure, ask away, hope your install goes smoothly