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Tips for dealing with door interlocks, not removing them!!!

CNCJockey

Plastic
Joined
Mar 19, 2011
Location
Southern USA
Our shop just got a new Daewoo Puma 400 lathe, it's our first modern CNC lathe and it has door interlocks and no key override, the boss already said they can't be tampered with due to OSHA rules so just figure out how to make parts "safely", so how do you do things like polish a bore that is a little small when the machine only allows 50 RPM with the door open in manual mode? And how about catching parted off rings when the machine does not have a part's catcher? These rings may weigh 5 to 10 lb. each and on our older machines we just use a long wooden stick to reach in and catch it but this machine locks the door closed when in auto mode and I don't want them falling in the chip pan, I could build a catch box but that's a pain, so how is the problem handled in the REAL world? And setting up new job's is a royal pain as you have to close the door to index the turret, and watching the tools approach a part can be a pain when the tool get's to a blind spot right before it get's to the part, I think these "SAFETY" rules can be more unsafe, I guess I'm just used to running old CNC lathes that required YOU to be the safety, this new stuff is just nuts. Thanks for any tips.
 
What I have done in the past is un-bolt the fork that's bolted to the door that plugs into the saftey interlock when you shut the door. We just plugged them in and the machine operates as if the door is closed.
 
Can you put an aluminum or wood rod in a turret station thats inside the part when cutting? I do this on a manual turret lathe on a part, first op is a turn with a cats paw tool the part off. The aluminum catcher is in the bor when I start the cutoff.
 
Can you put an aluminum or wood rod in a turret station thats inside the part when cutting? I do this on a manual turret lathe on a part, first op is a turn with a cats paw tool the part off. The aluminum catcher is in the bor when I start the cutoff.

I have thought of that, but was a little worried about a ring getting out of control, but it may work fine? Our manual lathes have a adjustable ring catcher that can mount in the tali stock with dual supports, but that kind of rig would be a big pain for the CNC.
 
Had the same issue with our Haas.
Have no clue about your machine,but on Haas you go to SETTINGS then to setting #51 (Door Lock Over Ride on/off) right arrow key till OFF appears then press WRITE/ENTER key and you are good to go.

It MUST be set every time the machine is powered down/up.

Would bet you a Coke in your setting pages there is a door lock over ride.

You have to be safe as you all ready know when opening the door with it running,but I would have some serious issues if I couldn't put a stick in the bore to catch a ring being parted off or making DAMN sure a tool doesn't crash into part or chuck while finger on feed hold button on a program first run :)
 
So the answer is no, you can't stick your hands in the machine to polish a bore at 50 RPM! :confused:

Yes he can, just no faster. :D

Anyhow, there are ways around it, laundry basket to catch parts, polish on another machine, those compounds shouldn't be in a CNC machine anyway.
If you get hurt with the interlock defeated there is going to be little sympathy for you.
 
You know,I really can't see the issue with needing to run the CNC with the door cracked open from time to time.We run manual lathes that have rapid buttons that will allow you to rapid into a part just as quick as a CNC,we do parting,turning and other dangerous things going on with nothing at all between the part and our teeth.
 
Had the same issue with our Haas.
Have no clue about your machine,but on Haas you go to SETTINGS then to setting #51 (Door Lock Over Ride on/off) right arrow key till OFF appears then press WRITE/ENTER key and you are good to go.

My neighbor has two new Haas's , and setting 51 is gone. It is now probably a hidden override that the user is not privy to.
 
This is one one to catch parts: Shop made bracket is mounted in adjacent tool block.
 

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And how about catching parted off rings when the machine does not have a part's catcher? These rings may weigh 5 to 10 lb. each and on our older machines we just use a long wooden stick to reach in and catch it but this machine locks the door closed when in auto mode and I don't want them falling in the chip pan, I could build a catch box but that's a pain, so how is the problem handled in the REAL world? And setting up new job's is a royal pain as you have to close the door to index the turret, and watching the tools approach a part can be a pain when the tool get's to a blind spot right before it get's to the part, I think these "SAFETY" rules can be more unsafe, I guess I'm just used to running old CNC lathes that required YOU to be the safety, this new stuff is just nuts. Thanks for any tips.

Actually those new safety rules are not to protect you, they are to protect me when I'm operating the machine behind you and you ram a chuck doing 2000rpm with the turret.
No good shouting look out because the jaw has already flown out of the machine and smacked me in the head* :bawling:

But as for catching rings.... I made up a special part catcher to go in with the part off tool.
It was some 8 mm bar bent and flatted and welded so that it formed an L shape in front of the parting tool
You moved the part off catcher infront of the the part then moved it to the part off position. reduced RPM to 200-300 for the last 2 mm so that the part did not have much spin energy... you can play with the angles on the bar so that it runs away from the part off tool and not forwards off the catcher.

Boris

* I was lucky..... it went over me by 3' and landed in the horizontal borer tray 15' further on :eek:
 
Actually those new safety rules are not to protect you, they are to protect me when I'm operating the machine behind you and you ram a chuck doing 2000rpm with the turret.
No good shouting look out because the jaw has already flown out of the machine and smacked me in the head* :bawling:

But as for catching rings.... I made up a special part catcher to go in with the part off tool.
It was some 8 mm bar bent and flatted and welded so that it formed an L shape in front of the parting tool
You moved the part off catcher infront of the the part then moved it to the part off position. reduced RPM to 200-300 for the last 2 mm so that the part did not have much spin energy... you can play with the angles on the bar so that it runs away from the part off tool and not forwards off the catcher.

Boris

* I was lucky..... it went over me by 3' and landed in the horizontal borer tray 15' further on :eek:

I used to catch smaller rings using exactly that system.... it works great and put a PROGRAM STOP right after the turret moves back so you can remove the part before the turret indexes..
 
Well, unbolting the key for the interlock is definitely one way to get around it.

As for checking for crashes, I don't see why you need to run your program and check for clearances at the same time.

An easy way I avoid that, Touch off the face of the part, set a Z0 that is close to the actual 0, Take the material out, then bring my tools to the furthest point in X and Z that they are programmed. Spin the chuck around by hand to see if any interference with the jaws is going to occur.

Really helps get rid of that "oh sh*t is that drill going to clear?!" feeling.

So, that's one solution to avoiding opening the door to check for clearance issues.

Polishing bores, turn the spindle on 50 rpms and get a die grinder with a slot cut on the end of a piece of rod to fit your collet, Insert sand paper and get to polishing.

Catching parts,

Try using your OD part off tool to part off until about .03 or .05(I usually leave less than that when I do this, parts about 3 - 6" diameter rings) And use a grooving bar with duct tape or some other soft cushy stuff around it to catch the ring as it parts off.

Use slow speed for the last bit, Works pretty good. Not perfect but it works.

Hope that helps
 
I've seen a rocker switch placed in a convenient but unseen spot that defeated the door interlock, worked nice. Got turned back on after setup was finished. :smoking:

I use a piece of 1' PVC pipe to catch rings, works great and doesn't scratch.
 
I used have a bar that would clamp on the tailstock, part almost all the way thru, advance tailstock, part off. Worked well and could catch several parts before the bar was full of rings.
 
I've seen a rocker switch placed in a convenient but unseen spot that defeated the door interlock, worked nice. Got turned back on after setup was finished. :smoking:

Oh yeah. I've seen hidden "modifications" like that as well. Usually done by factory service techs for fast cash on Saturdays when no one is looking.

The Haas "setting 51" has been eliminated, but, allegedly the function still exists "somewhere" in the control for only a select few Haas techs to know.
 








 
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