[tsnow678]

I am new to this forum and was wondering if someone can help me with a situation. I have about 20 years of machining experience but only 2 years of CNC experience. I have 4 Polygim(Diamond/Cubic) 25CSL swiss lathes that have Mitsubishi controls.

My dilema:
I have to use my live tooling up top (endmill) to turn a radius on two sides of a rectangular shape. I read through the Mitsubishi manual and found that I need to use a G12.1 code to make this happen. I am not familiar with this particular code and would like someone to walk me through it. Maybe a snippet of a program? Any help would be greatly appreciated!!!

[ProProcess]

G12.1 is an option, is yours turned on?
The tool holder needs to be a "face milling" holder i.e. the endmill is in-line with the stock, not perpendicular or "cross milling" holder, do you have one of these?
Does your machine have Y-axis "up top"?
If you have the option, the correct holder and do not have Y-axis than G12.1 is what you need.

Answer these, and I will assist you further.

[tsnow678]

G12.1 is an option, is yours turned on?
The tool holder needs to be a "face milling" holder i.e. the endmill is in-line with the stock, not perpendicular or "cross milling" holder, do you have one of these?
Does your machine have Y-axis "up top"?
If you have the option, the correct holder and do not have Y-axis than G12.1 is what you need.

Answer these, and I will assist you further.

I called up the G12.1 in the program to turn on circular interpolation. To turn it off the manual stated to use G13.1. Is that right? I used every configuration I know of to get the G12.1 to work and nothing. I either got a P32 error or a 6** error.

I am trying to use the cross-milling holder and rotate the C-axis(main spindle)to cut a radius. The only options on live tooling from the end would be the sub panel in system 2. The problem with using the sub panel is the lack of a Y-axis. The live tooling I have above the main spindle does have a Y-axis but the tool will be perpendicular in relation to the part. I did find in the manual a G17 code. This allowed me to X-Y a radius but it is leaving a concave on the OD. The head height is only .020" so it doesnt look too terribly bad, I just wish I could get the main spindle to work in conjuntion with the live tooling.

If you need more information just let me know. I do appreciate you taking the time to help.

[dookie2022]

To use this function you need a z axis driven tool not a X axis type
I see that you are using a milling cutter and just rotating the c axis and you say that you have a radius in the work piece you will find you cannot remove this blemish but you can minimise.
The milling cutter has to be a centre cutting type and you have to move the centre of the cutter off centre to the spindle axises by several mm.
As you need to experiment with cutter offcentre to achieve minimal blemish

[tsnow678]

To use this function you need a z axis driven tool not a X axis type
I see that you are using a milling cutter and just rotating the c axis and you say that you have a radius in the work piece you will find you cannot remove this blemish but you can minimise.
The milling cutter has to be a centre cutting type and you have to move the centre of the cutter off centre to the spindle axises by several mm.
As you need to experiment with cutter offcentre to achieve minimal blemish

Actually I am not moving the C-axis at the moment. I have the main spindle locked and using the end mill to X-Y (G17) to create the radius.

I would like to have the ability to rotate my main spindle while using the X-axis live tooling. According to the manual I should be able to use a G12.1 maybe I am way off here. I really do not know. When I try to unlock my main spindle to use the live tooling, I get an error. I cannot remember the error code at the moment. Normally I call up S1=0; but with the G12.1, from what I have read, it would be C0.

[ProProcess]

Is it possible for you to post a print of scetch of your part?

[tsnow678]

Is it possible for you to post a print of scetch of your part?

I would love to post the exact mfg. drawing bu without a confidentiality agreement I cannot. I will try to rough sketch a .png drawing this evening. Thanks

[ProProcess]

That would be great.

[Ovrclck350]

I agree with the above---I think you'll get more responses if you post even a crude drawing of what you're trying to do.

There's a lot of things you can co with the G12.1 option--even from the tools up top--but it helps to see specifically what you're attempting in order to help. G12.1 when using the tools up top is primarily used, in my experience, when trying to mill features on the OD of a part---like engraving---without having to manually convert all the coding into C-axis coding. Milling a radius (the way I THINK you're describing--with the radius sweeping from ID to OD while viewing from the front) should be possible, but it would require a ballnose and a better idea of the part feature.

[tsnow678]

Forgive me for the rough sketch but here it is. The first issue is the lack of knowledge to utilize my C-axis. Even if I can use my C-axis the center point of the stock is not centered of the part. So if I rotate the C-axis and try to meet the radius on two different diameters I fear it will not be possible. Even if I offset the endmill to the center of the radius I am still rotating the part to the center. Can you strike an arch while rotating the C? How can I get my C-axis to move while the live tooling is working? Is there an alternative to forming the radii another way even if my Z-axis live tooling has no Y-axis? Any and all help is appreciated!!!

[ProProcess]

Sorry to say, without Yaxis or without a "face milling" holder and G12.1 you are not able to produce that shape.
If you are able to borrow a face milling holder(end mill is in-line with the stock, not perpendicular) you would be able to use G12.1 and it would be like milling around the part as if it were on a mill.
Your machine dealer may know of a local user that has a holder you could borrow or rent to do the job.
Good luck.

[tsnow678]

Sorry to say, without Yaxis or without a "face milling" holder and G12.1 you are not able to produce that shape.
If you are able to borrow a face milling holder(end mill is in-line with the stock, not perpendicular) you would be able to use G12.1 and it would be like milling around the part as if it were on a mill.
Your machine dealer may know of a local user that has a holder you could borrow or rent to do the job.
Good luck.

Without the Y-axis is it safe to assume I cannot cutout the shape even if I had a face mill holder? Is there any alternatives to doing this shape over head in the perpendicular position? I did somewhat accomplish this but had the end mill diameter leave its shape (concave) over the arch.

[ProProcess]

Without the Y-axis is it safe to assume I cannot cutout the shape even if I had a face mill holder?...

Quite the contrary, with face millling and G12.1 you can 100% mill that shape, provided it's not longer than the endmill.
Here is an example of milling interpolation...[ame="http://www.youtube.com/watch?v=epI1M5CDIEQ"]video[/ame]

[tsnow678]

Ok now I really feel uneducated, lol!!! Where in the world would I begin to write the G12.1? I have seen at tooling shows such as the IMTS and the PMTS that some of the machines out there have programs that help with such milling operations. I have to hand write everything for my machines. If I could ever get a basic program written I could take it from there. I just have no clue where to begin. Where can I get my hands on such a program? 99.99% of my programs I can write on the fly with out a hitch but with something like this I am setback. I have discussed with my superiors the need for further education and hopefully 2012 I will get some. You have been a big help so far and any further information you care to share would be greatly appreciated.

[ProProcess]

...Where in the world would I begin to write the G12.1? ...

That's the beauty of G12.1 you just program the shape in X and Y as if it were on a mill.
The machine figures out how to move X and C to get the shape to come out correctlty..