I'm not sure if this is an option or if it even exists at all but, has anyone heard of a machine setting in which, say for instance, a drill or tap breaks.The machine detects the lack of pressure on the spindle and automatically alarms out. I'm asking cuz I think something like this would be beneficial to my shop.Please reply if you know of anything along these lines that could accomplish this.
I have a Matsuura mill...
with a Yasnak controller...
There are 4 small air nozzles very close to the spindle... In the manual it says, these small jets of air, are for detecting tool breakage...
I have not tried it out... because i have not broken a tool "YET"... But from what it says, there is a way with air, to detect a tool breaking...
If you want more details, just ask, and i will go into the manual and check it out with more detail and let you know...
I know DAH-LIH mills had a method of touch sensor current running through the tool and if the tool broke the current dropped to zero and detected a tool breakage, I don't know how well it worked.
There are some sytems that will also detect over-current on the spindle and back off the feed automatically.
If your controller has a " skip if no input" and have available inputs, then you can rig something up to check the tool at the end of the cycle. Dirty but cheap, I've used it for checking the drill before shoving the reamer into a a hole < or lack of a hole>.
You can't use it in the middle of the cycle, so the only option is to check at the end, or program a check between individual tapcycles but that will get old soon.
One more thing. HAAS has the ability to either feedhold or reduce feed if the spindle load exceeds a set value, very very valuable on the lathe, usable on the mill to let you know that the tool is getting dull, but it does not help if you want to see "lack of " spindle load.
I'm interested in this also. But in my application (making several passes roughing out some cast iron using a 12 mm round insert) how would the machine know that the tool didn't just quit feeding and raise up to go back and make another pass? Would there have to be something programmed into the code so the machine would know "I'm supposed to have pressure" or "No pressure is fine now".
What's with this electrical contact idea? Just pass a small electric current through the insert? Sounds interesting.....
I think the electrical contact was used to see if the tool existed in its entirety after you've just used <or abused> it, and it was probably a drill/endmill/reamer on a mill and not a lathe insert detector.
I believe there are a couple add-on tool breakage
sensors on the market. I have seen adds in modern machine shop mag. Sorry, I can't recall any brand names.
I know Fadal monitors spindle load and will adjust cut params accordingly. No load (no tool) or high load (broken tool) can be set to flag and stop.
As to monitoring breakage and wear, renishaw has some neat systems. A sweet laser system, no need to even stop the spindle, just run it through the beam. Can measure diam as well for tool setting too!
Fadal has this? is it an option or something?
It would be if it was a Haas...
Fadal has this? is it an option or something?
Our Mazak, will do the overload thing, fairly accurately, watch you spindle load meter, say your running 36% and that at 40% you want it to start backing off, it will reduce feed slowly until it reaches 50% of your feed, at that point I guess the programmers figure your either screwed or don't know what your doing, and it stops. With the tool setter in the machine you can also program (I think its M39) and it will go back to the tool setter and check for a broken tool. I've gotten screwed on this deal when 3 of 4 teeth came off of an endmill, but its great at saving reamers, when you check the drill.
As for Fadals, the piece of crap we have might have that feature, but I doubt it, and if it did, I wouldn't trust it. The spindle load meter is just one of those cheap rows of LEDs you can get at radio shack and it either runs at 1LED(not cutting) 30%(cutting) or in the red(doing what the Mazak does at 35% all day long).
As far as the no load detection, sounds like a great idea, but overload protection would probably do you just as well, only it will catch the problem before you get to the no load situation.
Actually, the no load thing would be giant pain, what about as your feeding into the cut or leaving the cut? Or if you had a "special" person(engineering student) on the bandsaw that cut your stock at nice irregular sizes, since they can't quite grasp the non-whole numbers thing.
You would have quite a lot of no load situations, which could vary based on stock size or irregular casting size. The overload would probably be the best, with our Mazak, you can sit there and watch how long an insert will last, it will sit at 34% for say 10 minutes of cut, then jump to 35% and then five minutes later jump to 36% and then about 1 minute later start jumping 36-37% and then keep rising. The salesmen like it because we tend not to destroy their cutters, I like it because we tend not to destroy our cutters, and can pull endmills while they are still good for resharpening.
You could probably rig up some kind of load meter, watch a few parts, determine where you need to set your cut off point, and wire in a stop somehow. Sorry if I can't be more specific, I only learn enough at that particular moment to fix whats broken, but most machines have extra inputs, and I think with a little research, you could mickey mouse something together.
Well, I just saw a brand new < 1 month old> VF2, and it has an additional setting on the load page to feedhold or reduce feed for a pre-set vibration level.
As for option, the spindle load thing is included as standard on all HAAS-s lathe or mill, but not sure about the vibration thing though.
ACE, I don't think you ever mentioned what machine and control you have. As you can see, several different makes have this type of option. Fanucs have load monitors that can trigger either stop or scale the feed. Many machine makers take it a little further from that (ex: Makino or Mori) and you can use it to trigger a tool change to a back up tool(new tool) and run that instead.
You can write macros in Renishaw systems to do the same. Mazaks also have Tool Break Check options. They even have an option for the tool taper seat check (like if a chip got onto to the taper, so the tool isn't sitting right).
For a drill or a tap, you would have a sudden spike in the tool load. Most machines (that have this option) will have settings available on the "Tool Data" page (or something to that effect... depends on the make of machine). You should see a place to establish tool load.
If not, I would definately look into an after market, in the machine tool setting device (like from Renishaw). Then you can program tool break checks, back up tooling, tool setting, etc. Real helpful if you're running lights out, in a cell system, or just plain long cycle time jobs.
Thanks for the replies.Sorry,fanuc control
There are a variety of devices that can be retofitted to machines with Fanuc controls. It's a question of how many different styles of tooling you want to monitor, are you willing to impact cycle time (touch method w/probe or whisker sensor), and of course, how much $$$ are you willing to spend?
See our web site for examples - http://www.ovationengineering.com/cn...monitoring.htm
and - http://www.ovationengineering.com/touchprobesys.htm
Ovation Engineering, Inc.
050928-1705 EST USA
On a HAAS SL-20 tap a 4-40 thread at 1000 rpm. How much load does this produce? Can you see it on load meter? How does this compare with the instantaneous no-load variation of the spindle load?
Alternatively a 2" tap. No doubt you can see a large load here.
So it really depends upon the normal load your tool puts on the spindle drive.
On a HAAS SL-20 there is a variable #1094 or #1098 that gives you spindle load. With macros you can set a test limit or limits and take some action on a test failure.
This has complications from spindle acceleration. You may or may not be able to work around this.
A torque or force transducer on the tool would be better, but hard to do except in research situations.
A conductivity test as suggested above may require the tool to be electrically insulated.
An optical approach my be one of your best methods for broken tool detection, but not for testing for tool degradation.
One method I have seen used is "wanding" the tool through the laser tool setter on the machine. If it does not detect a tool it will either change it to another or stop with an alarm. This is especially helpful when using small tools that the machine cannot "feel". I have also seen this method also used for "counting" the inserts on a face mill. If one insert goes it alerts the operator. These are usually part of the Tool Life Management option on the higher end machines.
You could do this on just about any machine with a little creativity. A question I have though is what size tool, a large tool running at 100% spindle load is easier to in process check for brakage than a small one. This revolves around using the variable frequency drive pinouts that AC spindle motors will have, some older DC motor controllers will have this too. You would set a pinout variable voltage, usually 0 to 10 volt, based on amps used ( 0 amps - 0 volts )(50 amps - 10 volts). A motor loaded will use more amps than a motor unloaded. Then while in the cut use a M funtion (one of the customizable relays that are usually used for custom fixtures and autoloaders) to trigger a device to compare a set voltage to voltage from the variable frequency drive. If the voltage is low then have it trigger a slide hold or estop. These are also available trips that are used for things like pallet changers and autoloading. This is very easy to adapt to machines like Fadal. You must turn off the M function prior to the end of the cut or the system will trigger due to a free running spindle. Peck drilling cycle will not work with this, you will have to actually program the entire peck cycle as G code feeds. For those of us who are smart and program with software the M function can be added to the post processor this way you don't have to think about where to add it in the program its done automaticly. Just use that post set-up when you want monitoring.