Lathe door interlock

BottleBob wrote:


Unless the machine is very, VERY poorly designed, there aren't any codes to disable a door interlock, or any other safety feature that fundamental. At the very least, you'd need to change the ladder logic; and on some machines even that won't work, since the safety systems are all hard-wired (negative true logic, fail safe) into a black box that does all the safety stuff and just tells the PLC and the CNC when they're allowed to move. Nothing about it can be programmed in the field, and any attempt to bypass it pretty much puts the whole machine to sleep.
On a more practical note, as someone else mentioned: If you don't know how to bypass the interlock, then you probably shouldn't. Safety devices like this are typically very simple. That's what makes them so reliable. If you can't look at one, understand what it does, and see how to deal with it, then it's likely that there are other things you won't understand either. And some of those can hurt you.
I'm not trying to talk down to you, or to discount your experience. But if your experience doesn't include this, then it doesn't, and that's something any responsible person needs to consider before answering your question. I can infer, for example, that you've never worked with a factory technician while he/she was installing or servicing this machine, and DID disable the interlocks. That probably means that you didn't see or learn all the rest of went along with handling the machine safely under those special conditions. A little bit of knowledge - especially the wrong little bit - really can be dangerous.
It's often true that there are no safety interlocks on manual equipment. There are also no parts of a manual machine that just start moving all by themselves. And usually nothing that moves nearly as fast as a modern CNC machine. When you use a manual machine, you normally have the controls (clutch levers and start buttons) between you and the machine. On most CNC's, because of the way they're guarded, it's common to lean into the machine, leaving the controls behind you, over your shoulder, where you can't get to them if something bad starts to happen.
Safety IS more important than the inconvenience of taking your parts to the manual machines. So is setting a good example. If you have decades of experience, then its likely that there are younger people around you who, like you 15 years ago, want to hear and see what more senior people have to show and tell. Even if you don't hurt yourself, you could easily help someone else get hurt without even knowing it.
And, if you really respect skill and experience, then the advice you've heard from this group, and the choices made by the people who designed and built your machine, ought to count pretty heavily.
Think. Be safe. And don't EVER let your guard down. That way, you'll be able to make more parts, and polish them on your manual lathe, tomorrow.
KG
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I was An Application Engineer for a Machine Tool Manufacturer and Installed MANY MACHINE TOOLS, They all had some way to bypass the lock. I can easily just unscrew the Plate and disable the whole Lock for good, but THAT IS DANGEROUS! I was just looking for a 1 event bypass
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Some of the machines I work on used to use a keep relay (DGN Bit). Or a key switch or a soft key setting. But nowadays the only way to disable them is physical.
--

Dan

CNC Videos - <http://tinyurl.com/yzdt6d
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Kirk Gordon wrote:

Kirk:
    On our Haas VF-6 mill, you can go to the option screen that says Door Hold Override (I think it's option 51), and change it from the default OFF, to ON. And the door interlock is disabled until the machine is restarted. It's part of the normal startup procedure everyone in our shop uses.
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BottleBob
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Captain Larry wrote:

No you didn't. alt.machines.cnc was created on Oct 1995, Friday the 13th to be specific, not Feb 1994.

It still is.
Have you pondered the situation where perhaps no one who has read your question has a definitive answer for it?
Having little CNC lathe experience, I certainly don't. Yet here I am chatting and trading info. Imagine that.
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Black Dragon

Politics makes strange bedfellows, and journalism makes strange politics.
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On Tue, 17 Feb 2009 04:33:31 -0800 (PST), Captain Larry
If you post here on bypassing a safety you will get negative responses (flamed) but at the core they advocate keeping people safe.
You are not alone http://tinyurl.com/ah2dp9
Tom
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On Tue, 17 Feb 2009 04:33:31 -0800 (PST), Captain Larry

Still helpful you just need a thicker skin.......and kill file Cliff.
Tom
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Captain Larry wrote:

I was once hired by some attorneys to survey the scene of an accident. Somebody who was just doing a little polishing got his arm polished off. Not my favorite kind of work.
KG
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