Mini Mill Prostrate Problem

[Dugg]

The Mini Mill we have at school drips coolant after the operation is completed. It'll drizzle about a tablespoon every ten or so seconds usually on my hands when I'm changing parts and do so for a minute or so.

At one time, I added a check valve to the flex linebut it eventually hydro locked and I tossed it.

I assume this thing is syphoning coolant which would suggest a vacuum breaker is needed somewhere in the system.

Any suggestions?

[HuFlungDung]

If the minimill is anything like the VF3 which I am familiar with, the coolant jacket surrounds the spindle cartridge, so there is a fair reservoir of coolant left in there and gravity will pull it down and out. Perhaps if one wished, you could plumb an additional loop of pipe onto the outlet, run it up to the top of the head and back down again, adding some kind of vacuum breaker valve at the top of the loop to stop siphoning, if necessary. It might not siphon for very long anyway without that detail.

[Janos]

I use one daily and have gotten it apart to service it from time to time. I have said a few profanities at Gene Haas for that one. The coolant line comes strait down off the cable jacket and goes into the nozzles, when you come to a stop it dribbles. Sorry but I tried to fix it too but to no avail. Now I just find a favorite position where the dribble doesn't get in the way and put that machine position number in the program.

(Example)
G81 Z-.5 R.1 F15.
G80
G0 Z.1
M5
M9
G53 Z0. Y0. X-6.25
M30
%

I got away from the usual G91 and G28, the same motion can be done with G53 and keeps me from making a screwup by not having a G90 in the next line.

Janos

[ddprecision]

At the end of prog. you could also use G110 X-8. Y0. X could be any # you choose

[Janos]

Hmmm... Never knew that. I may have to try that one. By the way, why does Haas do that anyhow? to switch back and fourth from G90 to G91 & G28? ( I know this is out of thread ) but please explain.

Thanks Janos

[pit202]

on our tm-1 we have plug in a one way valve , and this worked for a while ( a month or more ) maybe till the coolant was clean, now it is not workng :-) soon I will be cleaning the coolant tank so take a look at the valve.

if you ask for the G28 and G91 , there is a fine description at the manual.
I don`t see a problem with this, maybe couse I use only a CAM programs ?

[Dugg]

I program a G28 and just a Y0. to bring the table forward at the end of the Op. I dont use an X - as the Milli Mill only has the one access door and it's more difficult to load and un load. Also, I don't like the table moving at G0 under the tool changer in case I have something hanging down.

The Minni must have a be aware we've been talking as it seems to dribble more collant this week than before. I now just move the flex line out of the way and then forget to bring it back for the next green-button push

[ddprecision]

This is what is at the end of every prog. I write

G0 G49 G90 Z0. M9
G110 X-8. Y0.
G90
M30

What I do when I have a positive h offset is to move the table as far from the tool changer as possible I will do this say after a canned cycle.

G80
G0 Z.1
G110 X-16.Y0. table moved as far as possible from tool changer.
G0 G90 M9
G40 G49 Z0.
M1

If you went G110 X0. Y0. the table would move to the lower left side, so
G110 X-16. Y0. the table will move to the lower right side This is on a mini mill with 16.00 of travel

after you do the tool change call your h offset along with a Z.1 before you move to your wpc (fixture offset) hope this helped

as the programmer you should know of everything go on in side of your machine clearance etc.

G110 lets you put the table anywhere you need it to be. I run 4.00 toolex vises two vises on each machine, I just find the best place for load/unload

[Janos]

This is what is at the end of every prog. I write

G0 G49 G90 Z0. M9
G110 X-8. Y0.
G90
M30

The G90 is only necessary in the first line of the program and only needs to be used once unless G91 (incremental) wants to be canceled.

Typicaly I end a tool usage with the G53 and a machine position number because all other machines in the shop are Fanuc controled and that is what they like. So if I need to rob a pgm. off of the Haas all I have to do is change the 6 digit O number to a 5 digit. and bingo, Hardinge pgm.

Oh yeah, if you have a prob with a possible collision with the tool changer you might be able to use a G38 (I think that's it) to move the carousel around to an empty pocket before you continue with making chips. It will go back to the socket on a M6 but make sure to G53 or G110 X-15.5 so it wont adjust an offset for you.

[Janos]

I now just move the flex line out of the way and then forget to bring it back for the next green-button push

I bet that can get a bit aggravating to do after a while. I run a ton of 2 min. or less parts, and that would drive me up the wall. I like to use the single block and the Hand wheel feed override to dry run a part. You can get real intimate with how close a toolholder gets to the workholding device. It helps to keep you from making any unwanted noises. Grind, Grind, Screech ect...

[ddprecision]

G0 G49 G90 Z0. M9
G110 X-8. Y0.
G90
M30

I should of said this is how my post post's

[Janos]

looks alot like a post processor's code.
do you use the Haas post when it writes the code?

I started out pretty dependant on mine (post processor) but as time went on a guy I work with got a little bent at all the "extra" stuff that mastercam puts in. like unnecessary tool positions and G49 G91 G28 and then starts out the next tool with a G90. I find it becomes much easier to edit when you get rid of the redundant bits.