Newbie- Lights out....Unattended operation

[behindpropeller]

Folks...

I'm looking for some advice.

I'm going to run some parts in our TM-2 unattended. I know our machine is slow...should not be used for production...yadad yada... but...

The $$ I will make from these parts will allow me to buy other engineering and manufacturing tools.

So I have a part that takes some hogging and takes 45 mins to run. My plan is to make a fixture that will run three of these at a time. I will throw them on the machine before I go to work a few days a week and go from there. These parts require a second op which will be about 10 mins each on the 4th axis (mostly just drilling/tapping).

I don't want to be a green button pusher but this will give me some $$ to buy more tools and technology.

What settings do you set up on your machine? Do you probe every tool before it cuts? I have a VF-2 coolant tank on my TM-2 now, but have not figured out where to hook up the tank level sensor.

Advice....??

Thanks

Tim

[Al_The_Man]

Originally Posted by behindpropeller I have a VF-2 coolant tank on my TM-2 now, but have not figured out where to hook up the tank level sensor.

In the absence of any pre-assigned input that may be on the machine, you could wire the level sensor in series with the E-stop string?
That is if you want to stop the operation completely in the event of low coolant.
Al.

[Geof]

Advice?????

I haven't done 'lights out' but often let machines run unwatched for long periods of time and have learnt a few lessons.

Don't try to maximize metal removal by running tools at the upper end of their speed/feed range. This maximizes the chance that a tool will fail, especially if the coolant fails.

Checking coolant flow would be a good idea. I don't know where/how the coolant sensor connects but I think the tank level is less important than whether the coolant is actually flowing. If I was contemplating true lights out operation I think I would figure out a coolant pressure sensing system using a pressure switch and the M-Fin circuit.

Be really careful with drills, especially HSS because if you are pushing them in steel they can go from cutting to welding very quickly. This can happen with attended operation and you do lose the drill (and part) but with unattended you can lose all the tools following the drill.

Regarding probing for tool breakage I would do it before and after the tool is used. Probing after will detect if the tool broke during operation and can save you destroying following tools.

Set the tool overload conservatively such as 120% (or less) and have it decrease the feed rate not go into feedhold or alarm. If things go really wrong the machine will stop okay but this avoids stopping the machine just because the load spikes briefly in corners of pockets.

Can't think of anything else.

[Geof]

Originally Posted by Al_The_Man .....you could wire the level sensor in series with the E-stop string?.....Al.

On a Haas TM it would possibly be better to use the 'Door' switch. This stops the machine in a way that is easy to recover from once the coolant is topped up.

[Al_The_Man]

I'm not that faimiliar with Haas, does it put it in feed hold? and also stop the spindle?
Of course, you would also want to shut off the coolant pump.
Al.

[behindpropeller]

Originally Posted by Geof On a Haas TM it would possibly be better to use the 'Door' switch. This stops the machine in a way that is easy to recover from once the coolant is topped up.

Geof-

The "door switch" on a TM machine is the little Oh Sh!t button on the pendant that you have to hold down to make the machine move. Setting 51 makes it so you do not have to hold it down.

Tim

[Delw]

In running lights out on several different mills. my #1 problem has always been coolant, No matter what mill I have used the coolant blockage is always an issue.

#2 is drill breakage

#3 is exactly what Geof says DONT RUN A HEAVY LOAD on a lights out operation. slow it up ALOT cause something will always go wrong.


if you have run a bunch of parts of the same( and havent changed the set up), then your ready to run lights out, if you set it up and then run lights out your going to fail. again because somethign always happens and it usually happens 10 mins after you lock the door.

My only problem/fear I have with running lights out now is the airlines. a few times I hav run the mills with 4th axis trunions, my airlines have broke or the sperators have broke. one time cost me a 15hp 1 year old compressor, like I said if it can happen it usually will.

Delw

[mfgbydesign]

having programmed numerous unattended machining operations, there are a few things that come to mind:
1: reliability over speed in all aspects of the operation, and the other posters have addressed some of these.
2: tool life management based on history of running the job (number of pieces, time in cut), knowing when each tool needs to be replaced before it runs another piece. Redundent tooling if your machine has the capability.
3: set up all operations at once so each time you run the job you get a finished piece. You might consider two loads of parts, one for deburring & in-process inspection while the other is running. There are multiple advantages to using this technique which I can elaborate on if there is interest.
4: find out if your machine monitors tool, spindle, or axis loads. Identify the highest loads in your process & reduce them. Reduce them again. Set the machine to stop when these loads are exceeded.
5: if the same fragile tool is used for multiple operations consider adding tools. This isolates the effect of a tool failure to one operation.

[behindpropeller]

Great advice.

Thanks for all of the replies. Ill post back after I do a few test runs.

Tim

[SBC Cycle]

At 45 minutes each, you're talking just a few hours of unattended operation. If the coolant plugging is a problem (and it is for me when I'm making fine shavings from either 3D surfacing or lots of hogging), I would add a coolant off, dwell, then coolant back on in there somewhere. I've had numerous "lakes" in the chip pan before but never takes more than 5 minutes or so to drain off. Sounds like the parts will still be done well before you get back to them after work.

The advanced tool management sounds like it would come in handy here. I've not used it yet but it sounds great.

This is a bit of a tangent but yesterday I ran some parts that I haven't ran in a long time that has quite a bit of hogging. I used to use a 1/2" HSSCo "corn cob" rougher to remove the bulk of the material (hot rolled steel). Took about 40 minutes each. I rewrote the program to use a 5/16" Hanita Varimill and reduced the stepover so that it was taking a bunch of "light" cuts (0.148" radial step, 0.370" depth). I was running 5989 RPM and about 55 inches a minute, climb mill only. I went from 40 minutes to just a hair over 10 Best part is that it cuts so nice I even used the same endmill to finish it

I don't know the rigidity of a TM but even in my VF3 it liked the high RPM/FEED-reduced stepover a lot better than the hog mill.

Not saying I would attempt this "lights out", just saying maybe rethinking the method in certain situations is good food for thought. We used to do quite a bit of lights out in the past but have largely eliminated the reasons why we felt we had to.

[ROBBY 68]

There are two settings helpfull to leave machine unattended
SETTING ONE..... auto power off timer, amoun 30 machine counts 30 seconds then off

Robby

[ROBBY 68]

Again
SETTING ONE ....auto power off timer, amount in minutes when machine is idle after reading M30 it start counting value putted in this setting.
SETTING TWO.....power off at M30, after read M30 it gives30 seconds before power off.
Robby