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Help needed - Long Chang LC-16 vertical mill

MysticalDork

Plastic
Joined
Jan 18, 2022
(I accidentally posted this first in the machinery manuals/brochures section by mistake, apologies for that.)
Hey everybody,

I just recently got my hands on a used Long Chang LC-16CV CNC knee mill for my home shop, and I've been taking some time getting it all set up.
When I got it, the memory backup battery in the control was dead so I had to reload all the parameters, which was fun.
Now that the machine knows what it is supposed to be again, I've got an alarm which won't go away and I haven't figured out what to do about it. In the control it just gives "NC error - 1 - Sequence Alarm" which is not helpful at all, since there's no error code to look up. (The "1" is just how many errors/alarms there are, if I trigger a limit switch it increments to 2)
There is also a light lit on the front panel labeled "W MTR TH", which I'm pretty sure means the alarm is something to do with the power knee drive motor, which is the W axis on this machine. The manuals I have for the machine don't have anything about these lights.

Any and all info I can find on this old beastie would be wonderful - I have a full manual for the Meldas control, which is lovely, but the machine manual itself is... Sparse, to say the least.
The guy I got it from had it running for years before I got it, so I'm hoping it's something dumb and simple that I can fix easily and be on my merry way.

Machine type: Vertical knee mill
Machine year: 1985
Machine brand: Long Chang
Model number: LC-16CV
Serial number: 76070015
Control type: Mitsubishi Meldas M0
Problem type: Setup

PXL_20220115_014300053.jpgPXL_20220114_195448791.jpg
 

MysticalDork

Plastic
Joined
Jan 18, 2022
That was it! Real small thermal overload hiding behind a bunch of other stuff, so I missed it first time around.
 

MysticalDork

Plastic
Joined
Jan 18, 2022
Alright, next problem: The machine moves, and will follow commands entered in MDI mode, but I am unable to save a program from MDI to memory. I get an "Over Memory" error, which is a bit confusing seeing as the machine has had all its memory wiped by a dead battery.

I've seen some mention of a procedure to clear the program memory, but I haven't been able to find out what the actual procedure is anywhere.
 

Vancbiker

Diamond
Joined
Jan 5, 2014
Location
Vancouver, WA. USA
There are some secret parameters that set the control options and configuration. I suspect yours are not set. Not positive about the M0 model, but on an M50 those are not loaded when you enter parameters by hand. If you load the parameters using the ALL1 file then you should get those set. Did you reload by hand? If so, you might need to contact Mitsubishi for help.
 

MysticalDork

Plastic
Joined
Jan 18, 2022
I don't have a parameter file or a way to load one at the moment (I've ordered an RS232 card but it hasn't arrived yet), so I did load the parameters by hand off of the machine manual printout that I have. I'll bug the folks at Mitsu again tomorrow and see if they can dig anything up.

The ones I did set were accessed by setting bit 7 of address H1001 to 1, the machine parameter menus are hidden otherwise.
 

DouglasJRizzo

Titanium
Joined
Jun 7, 2011
Location
Ramsey, NJ.
Alright, next problem: The machine moves, and will follow commands entered in MDI mode, but I am unable to save a program from MDI to memory. I get an "Over Memory" error, which is a bit confusing seeing as the machine has had all its memory wiped by a dead battery.

I've seen some mention of a procedure to clear the program memory, but I haven't been able to find out what the actual procedure is anywhere.

Unsure of the controller, but many will not allow MDI commands to transfer to program memory. You may have to actually "write" the program in memory/edit mode.
 

MysticalDork

Plastic
Joined
Jan 18, 2022
Meldas M0 memory format procedure

Found it! Called Mitsubishi this morning and they were able to dig up the proper procedure. Since the PDF they sent me is too big to upload here, the Cliff Notes version is that you have to go to the I/O menu, go to page 5, and type (1) (INIT) and press [input] to clear addresses 1 through 7999. Repeat with (2) (INIT) for 8000-8999, (3) (INIT) for 9000-9999, and (4) (INIT) for canned cycles, then power off/back on the control and you should be good to go.
 

MysticalDork

Plastic
Joined
Jan 18, 2022
Tool changing and work offsets

A couple new issues have reared their ugly heads. It appears that this machine didn't come with the (factory optional) ability to set work offsets (G54, etc). The control itself is capable of it according to the manual, but the screen where that info would be entered is not available on this machine.

How would one go about getting those to work? Is it a combo of dip switches or something in the control cabinet? An add-in card? Something that gets typed into the control?
Please help, I'm currently stuck using the machine origin coordinates which makes programming the thing nightmarish.



Second problem: If I call a tool change (for example T1 M6), the machine throws a "sequence alarm". Haven't found any good solid info about what that means or how to get around it. Sharp doesn't want to help because it's too old, Mitsu are nice but they only have limited info also due to age, and I don't speak Mandarin so I can't get anything out of Long Chang in Taiwan.

I should mention that this machine doesn't have an automatic tool changer, only a power drawbar system controlled with some buttons on the spindle head. I suppose I'd expect an M6 command to pause, home the Z axis and await manual tool change before resuming the p, but it doesn't even do that.

Possibly related to the tool change issue - As seen above I've managed to get all the parameters, settings and canned cycled back into the machine, but in the back of the manual there's a picture of some 1's and 0's starting around address H50 in the "sequence" screen that I think need to be reloaded just like the other parameters, but nothing I do will make them stick. I can enter them, but they disappear as soon as I restart the control.

Both these issues mean that I'm currently limited to very rudimentary programs, mostly handwritten and single-tool. Any help with them would be most appreciated.
 








 
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