Cycle start not working - SL3B

[andy.f]

We have a Mori Sieki SL3B with Yasnac 2000B that right of a sudden dont want to start when Cycle Start is pressed. Every thing else works, no alarms so not sure what to do. I dont have service manual so I am not sure what to check.

Any help is greatly appreciated!

Andy

[Mitsui Seiki]

What exactly did you do before this happened?

[andy.f]

Originally Posted by Mitsui Seiki What exactly did you do before this happened?

Nothing what soever. I had the shop closed, went on holiday, came back and cycle start dont work. It seems like also the reset button dont work as I cant clear buffer memory in edit mode. this control is built like a tank and I dont think it will just break down while not under power. Very strange...

Andy

[Mitsui Seiki]

Very strange.
Do you have air to the machine?Fuses?

[andy.f]

Originally Posted by Mitsui Seiki Very strange. Do you have air to the machine?Fuses?

Hi Stefan,

Thanks for replying. The lathe dont use air. Only hydraulics and that is fine.
I checked for fuses but could not find anything. It seems like some type of interlock, but it has none other than cabinet doors and chuck clamping.

Andy

[Mitsui Seiki]

If the chuck has sensors,see if they work.Same goes for the door locks.
Maybe the chuck is jammed.Open and close it a couple of times.

[neilw20]

It looks like it is not the chuck, but it could be some contacts related to the safe closed position.

It has it been set for ID gripping, and you haven't noticed it?

OH well...

Turn off main power.
Find all of the limit switches, guard/door switches, and cycle them all mechanically.

Probably a stuck, but most likely open contact.
This applies to any switches/sensors on tool changers/turrets and the like.

Poke and turn all of the controls every where they exist.
Turn it on and hope you have found it.

You can spend hours doing one at a time, and identify the culprit, but in my experience any thing really crook will come back soon enough, then eliminating the good ones becomes the next exercise.

Neil

[CNCWerks.com]

Hello,
Today I was working on a similar (cycle start) problem on a SL-1A with Yasnac LX2. The problem on this machine was the magnetic proximity switch for the turret clamp position wasn't working. It did give a "turret unclamp" alarm though. It was possible to troubleshoot with the diagnose 1013.7 TPCL, which wasn't changing when the turret moved into the clamp position (with your machine will/could be a diff. diagn.). Does your oper. panel have a TRST LED above the turret index p.b. (which should light up when in clamp)?
Good Luck,
Oliver G.

[andy.f]

Originally Posted by CNCWerks.com Hello, Today I was working on a similar (cycle start) problem on a SL-1A with Yasnac LX2. The problem on this machine was the magnetic proximity switch for the turret clamp position wasn't working. It did give a "turret unclamp" alarm though. It was possible to troubleshoot with the diagnose 1013.7 TPCL, which wasn't changing when the turret moved into the clamp position (with your machine will/could be a diff. diagn.). Does your oper. panel have a TRST LED above the turret index p.b. (which should light up when in clamp)? Good Luck, Oliver G.

I opened the pendant and traced the wires from the reset and cycle start button. I found that one black wire was cut (deliberately) by pliers halway between the reset button and the board. Just to try I soldered it back and now the reset and cycle start works. However it doesnt work to up load a program from the BTR board any more. I get parity error with same settings as before in the software. I think the black wire was cut by the previous (or original) owner, maybe to cut a ground loop or similar and that reconnecting the black wire enables reset and cycle start but regenerates the ground loop. another theory is that lighting struck while I was away and destroyed something on the board where the I/O circuits are for tape communication.
I tried to swap out the hex inverters, but it didn't help. I guess I have to be happy the machine works, but I hate manually inputting the programs...

Andy

[neilw20]

Put a switch in ther broken wire labeled for emergency use only (LOL)

[andy.f]

Originally Posted by neilw20 Put a switch in ther broken wire labeled for emergency use only (LOL)

I wish it was that easy! If I disconnect the wire I cant load the program as both Reset and Cycle start buttons are needed to start the transfer.

It is hard to try to track down damaged IC's on the controls Tape in/out board as there are no schematics available even from Yasnac.
Hard work these old dinosaur machines, but I dont want to scrap it as it cuts great.

A new control maybe, but retrofits cost both arms and both legs...

Andy