[Sub_Apprentice]

Hi all, before you ask. No I do not know the model number or anything like that. I am a end user in a family owned foundry working on a machineshop startup so we can machine our own parts. Alot of information is unknown about the machine we aquired but what is known its old and hardly works sometimes


Sooo what it is doing on a short simple program is almost always on my 3rd tool change out back to tool one to start over the spindle will freeze up mid tool change. I have hydraulic fluid, its been warmed up with about 10 minutes of dry runs to get that flowing. It is however a open vertical mill so my spindle gets lots of coolant blow off and chips on it. I blow it out every few parts to ensure nothing gets "worse". Apparently that doesn't help

Has anyone run an older le blonde vertical mill and experienced anything like this and knows a possible fix? any help or ideas how to fix or solve this is much appreciated

[fizzissist]

the problem is intermittent?
If it isn't, it's your program.

If it is, it could be you need to go through it and clean/calibrate all the switches and contact. Wiggle the connections, make sure they're clean.

If it works at all, that's your biggest clue.

[Sub_Apprentice]

maybe I used the wrong term. the tool holder arm that has all the tools stored to switch in and out. It freezes in mid tool change when I am trying to switch from tool 3 backto tool 1. The arm will come over grab the tool in its slots then freezes.

If by connections you mean all the electronics in the panel we have fiddled with them a few times trying to ensure their secure, however are most cnc machines not really built for withstanding large amounts of vibration? We have a sand shake out machine not 200 feet from my machine that is used to break sand apart after its been used. It does a good job of shaking the floor near me. Would that cause my connections in the electronics to come lose more often then I am aware?

[fizzissist]

From T3 to T1 only,,, or from any tool to 1... and only to 1, not to any other tool? Hmmmm

Something in the mechanism where there's interference with that tool.. Not knowing your mechanics, hard to even guess.

Does shaking out your sand create a lot of fine dust? I wouldn't think you'd have all that much,,, but maybe it wouldn't hurt to have a suction system to move the dust away from the CNC anyway. Not good for ways, tool tapers, coolant, etc. anyway.

[Sub_Apprentice]

This place is shall I say the anti cnc zone. Everything about this building I am in is dirty and full of particles flying around and getting in my machine. I blew the back of the controller off near the fan last night and alot...alot of dust came out of the fan and vent off the controller.

It mostly does it at the end of the program going from tool 3 to tool 1. However it does this on any program/job I run, its usually just more random with larger programs and tool selection. This program/job has been an issue since I started doing this. I can run longer programs with little headache, short and quick like this... it hates.

As far as specifics sorry I wish I could tell you more about the machine all I know for sure its a Le Blonde and runs on a Fanuc 6m controller. I can't even find a model number on the thing. and my manual i have is for the controller

[underthetire]

Probably the tool clamp/unclamp switch or arm at spindle side switch. May even be a shot drawbar, so it's not unclamping all the way, crunching broken bellville springs on its way down. Try to pry the tool out of the spindle with a small pry bar. If it moves at all, you probably found the problem.

[Sub_Apprentice]

would it only effect one tool location in the sense that 95% of the time its tool 3 that it freezes up on? I have my electrician checking connections now to see if he can poke something right to stop this. But if its something in the spindle thats broke. Thats not something I or anyone here knows much about.

When you say use a pry bar to pull it out does that requires alot of force if its broke or would it pretty much fall out with a little bit of pressure?

[underthetire]

A 40 taper machine should hold the tool with about 1800LBS of force
A 50 taper machine is about 4500.
A 14" long or so pry bar with a moderate amount of force should not be able to move the tool. If it falls out, stop running the machine, your going to kill someone.

If its only one tool, it could be a bad pull stud, or if its a roughing tool or high spindle speed tool, you could have a bad holder sticking in the taper or the spindle is bad heating up the tool and sweating the taper in.

[RICHARD ZASTROW]

Is tool #3 always physically the same tool? I know many shops with older machines use a tool library that always uses the same tool in the same pocket. So if you have a tool with a bad taper or as underthetire says, a bad pull stud, it always creates the same condition.

The dirty foundry conditions really do not help, I had the same problem back in a past life. The iron dust was so bad we had to pull the circuit boards out and wash them in a 5 gal. can of cleaner, blow them dry and reinstall them.

Dick Z

[Sub_Apprentice]

:banana:

Yah it is generally in the same location. My controller doesn't know the difference of where I put it, ie in location 5 9 or 14 or 1. If I say grab t1 it grabs t1. It also doesn't remember if i move the tool spindle to another tool, i have to manually move it back so it will grab it back into tool 1.

as for pull stud, i don't use the same tool holder every time. I had 4 tap holder setups with different pull studs on. It did the same thing on all 4. I figured it had to be something related to wiring, as fizz suggested. He wiggled stuff in the controller and it never did it again yesturday.

However today it for some reason after running a few dry cycles to get the hydraulics flowing for the day it froze up and said it was too hot with a warning light on my control board. FUN...not

[neilw20]

I've seen machines in dirty environment and limit switches end up sticky causing tool change cycles to freeze.
Find all the hidden limit switches and make sure they work.
Some of the older switches often seem to work, but the contacts are no longer reliable.
Typically the tool change position, at least in older machines, is sensed by multiple switches, like 3 switches for 8 positions, 4 for 16 etc. It appears it always 'thinks' it is at tool 1 position.
Sometimes relay contacts have the same disease. Evaporated stuff out of the air ends up on the contacts.

[Sub_Apprentice]

Thanks, I will have to have my electrician check those next time he is in it. I found out today as well I should check the filters to make sure they are "clean" even though I know if i have any in the machine they will not be clean.

[LUCKY13]

the problem is intermittent?
If it isn't, it's your program.

If it is, it could be you need to go through it and clean/calibrate all the switches and contact. Wiggle the connections, make sure they're clean.

If it works at all, that's your biggest clue.

I will have to agree with this. One thing, if your going to run a older machine you need to tear into it and learn what makes it tick. This is the only way you will be able to keep it running unless you pay a teck to come and fix it every time some little thing happens.


Tool changer switches, contacts, WIRING HARNESS (check for bear spots that can touch when it is in movment), Z axis limit switchs, spindle index sensor (if it has one). Also what ever motor/drive the tool changer has needs to be checked. It may have more than one that gives it the movements and in a timed system like this it could be indicating a bad spiont in the motors rotation.


In other words any and everything envolved with these circuits/mechanical sections.


The foundry thing is a big problem. This stuff gets in on the circuit boards it can cause great problems. They can be removed and cleaned (electronics and boards), but if they need to be. Then you need to add a filter system of some kind. You need to add a filter system of some kind no matter what if yuo wish to run electronics in this eviroment (like a air filter for fan system).


I know it may seem like a big undertaking to start tearing into a machine like this, but really its not. You just have to break it down into different little system and start testing. Limit/homing switches can be pretty easy to check. Finding shorts or wiring grounding out can be a bit harder but its not that bad really. Moving wiring around with a meter hooked up and tell you alot.




I guess you where hoping someone has come across this very problem but with older machines there can be so many little things to cause problems that its kinda hard to test unless you are there at the machine. Plus not many people running a older one as compaired to something like a Haas which many people are running.


Jess

[Sub_Apprentice]

I agree that is something that should be done,however is it something a person like myself can learn to do with little to no electric knowlage. Or my company has a onstaff electrician, but not he usually doesn't have time to do something like a full tare down of a machine to learn/clean it.

As for a air filter system does it need to just cover the vents of the machine or how does it need to be used near it? Sorry I am way to new at this and I am learning alot with much headache. Specially since the machine is shall we say dirtys dirtier cousin.

Thanks again everyone for the help, I appreciate it alot.

[neilw20]

Positive pressure ventilation will keep out the dust.
You put a slight positive pressure in all the sensitive electronic / electrical enclosures.
Make sure the inlet vents have filters, and keep them clean.
I rigged up a system for my friend and he never bothered to put filters on the inlet as instructed.
Dust eventually clogged and killed a 15HP VFD.
Block the inlets???? Well it won't last long then!!
Often there is maybe 1KW or 2KW or more of heat to remove!!!
Some method should really be considered, like a vane in the airflow to set off an alarm when the airflow is reduced due to blocked filters.
Another way:

And another as used on big machines I have seen.
Fully sealed enclosure with an air conditioner to control heat transfer.