[bxlor]

Hi all. I have a Mori ZL-35 4-axis lathe with an older Fanuc 0-TTC series controller. What I am trying to implement is a "dummy" tool to check part lengths before the actual machining process. Where I am stuck is getting the "dummy" tool to feed in on a G01 command without any spindle speed (I don't want the part to rotate when feeding in to check length). My question is, is it possible to issue a G01 command without any spindle speed settings?
here is a snippet of my dummy tooling program for head 2 (bottom turret):
M25
G98
G10L2P0X0Z0
G10L2L1X0Z-55.0982
G50X14.25Z35.076
G0T0707
G0X5.6Z34.356
G01X5.5F0.010 <--------(this is where the program hangs up and no movement occurs)
G0G28U0
M100
Z35.076

As you can see, I only need that 0.100 movement to determine if the part is present, but the turret will not move.

Any help or ideas?

[deputydawg]

You can't feed .01" per revolution with out the part spinning. How does the machine actually determine whether or not there is a part present simply by feeding .1"?

[bxlor]

Thanks deputydawg.. You pretty much answered my question about G01 commands without a spindle speed. As for the .100 feed in to determine part length, what I'm actually doing is trying to create a controlled crash to trip servos if the part is too long. Parts too long are usually due to a missed operation prior to the lathes. I rather take re-homing the machine than create scrap and crashing out the machine. What I'm using is a tool blade that moves to approx 0.125 off the edge of the part (if had been faced/bored prior to lathes) and approximately 0.070 off the OD. If the blade touches part.. Part is too long. If blade doesn't touch a part, the regular machining cycle continues. Yes, its a crude but simple poka yoke to prevent the machine from running if parts are too long. And yes, I've looked at sensors and probes that would be better options, but unfortunately, I don't make decisions to capital expenditures.

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[bxlor]

Also.. I figure the .100 feed in at 0.010 in/min shouldn't harm the machine at all..

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[deputydawg]

Lathes generally don't feed in in/min, but you might be able to spin the part at a couple rpm, and feed in at .1 per rev. I don't know if this will simply trip a servo however, unless you've had luck doing this in the past.

[bxlor]

Lathes generally don't feed in in/min, but you might be able to spin the part at a couple rpm, and feed in at .1 per rev. I don't know if this will simply trip a servo however, unless you've had luck doing this in the past.

well.. I've tripped servos utilizing a similar scenario for machining centers (to prevent operators from putting caps on backwards), and it works flawlessly. I've also tripped servos when trialing this in manual on the lathes. Just for the programming portion on the lathes, I guess a spindle speed is required to get movement with G01, something that isn't required on the mills.

Just to add, I've also tried the same situation with a very low spindle speed setting. But I continually get spindle speed alarms when doing so. Don't know if there is a minimum rpm required on low gear. Anything over 5 rpms could tear up/wear out my dummy tool. Same as feeding in too fast, which could tear up the dummy tooling, or worse, tear up the machine bearings.

[deputydawg]

If I started writing programs that wouldn't run if a prior operation had been skipped, operators would pay even less attention, and I'd have to modify thousands of programs. Perhaps ensuring proper flow of work would improve efficiency on all jobs, and seems like the ultimate goal.

[alan_3301]

I've never operated a "real" control, but does yours support g94 / units per minute feed?
maybe try that with the dummy tool, and switch to g95 / units per revolution feed mode for your real tools.

[deputydawg]

That's worth a try. I never used it, but it may be the code for a machine equipped with live tooling, so you may have to define the "dummy" tool differently if it alarms out.

[bxlor]

If I started writing programs that wouldn't run if a prior operation had been skipped, operators would pay even less attention, and I'd have to modify thousands of programs. Perhaps ensuring proper flow of work would improve efficiency on all jobs, and seems like the ultimate goal.

That's true. The problem though is to have a fail safe in place to prevent scrap/crashes should operators forget and miss an operation. Shouldn't be happening because operators have to handle and clean every part prior to the lathe operation, but should they get distracted or side tracked for whatever reason, they easily forget whether or not the part went through the first operation. Typically they have a part waiting to go into process for the first operation while a part is being processed. All I'm trying to do is put in preventative measures to prevent the lathes from crashing because of a missed operation.

[ThePrecisionist]

You are on the right track using G98 (inch per minute). But what you have wrong is the feed. When in G98 mode think of the lathe as a mill. You need to feed F1.0, 5.0, 10.0 etc.
If you ever use bar pullers it's the same switch to G98 and use ipm feeds.

[makinstuff59]

Hi all. I have a Mori ZL-35 4-axis lathe with an older Fanuc 0-TTC series controller. What I am trying to implement is a "dummy" tool to check part lengths before the actual machining process. Where I am stuck is getting the "dummy" tool to feed in on a G01 command without any spindle speed (I don't want the part to rotate when feeding in to check length). My question is, is it possible to issue a G01 command without any spindle speed settings?
here is a snippet of my dummy tooling program for head 2 (bottom turret):
M25
G98
G10L2P0X0Z0
G10L2L1X0Z-55.0982
G50X14.25Z35.076
G0T0707
G0X5.6Z34.356
G01X5.5F0.010 <--------(this is where the program hangs up and no movement occurs)
G0G28U0
M100
Z35.076

As you can see, I only need that 0.100 movement to determine if the part is present, but the turret will not move.

Any help or ideas?

The feedrate of .01 IPM would take 10 minutes to complete the .100 of movement