Haas TL2 programming

[rainman]

Hello,
We're about to obtain a Haas TL2 toolroom lathe. I understand this is a front turret machine, as opposed to the normal layout of a rear turret slant bed lathe, which is more typical. My question is, is it programmed the same as a rear turret machine (and the Haas control reverses things), or would X be negative, arcs be reversed from a rear turret machine? In other words, going around a rounded corner on the OD would be G03 on a rear turret machine. Would it be G02 on this machine (since the actual machine motion would be CW)? Or would I program it as if it were a rear turret machine, and the Haas controller does the reversing?

 

[chineshop_guy]

nothing different form a slant bed coming from opposite directing.
your x's will be positive, z's negative values

 

[rainman]

Still wondering about arcs though...

 

[gcodeguy]

Still wondering about arcs though...

Not familiar with that lathe, but if Z minus is from the face of the part towards the spindle, then G2/G3 should be the same. Now if it is Z plus, then the arc codes are reversed on every lathe I've worked on.

 

[sinha]

Short answer: G02/G03 will get reversed, compared to a rear-type lathe.

Explanation: The positive direction of the X axis is always towards the tool, be it a front-type or a rear-type lathe. The positive Z axis is towards the tailstock.
The Y axis is defined also on a 2-axis lathe, even though it is not programmable.
As per convention, right-hand coordinate system is used: Curl your right-hand fingers from the X axis to the Y axis, and stretch the thumb. The positive Z axis will be in the direction of the thumb. With this convention, the Y axis on a rear-type lathe points towards us, while it is away from us on a front-type lathe.
For deciding the CW/CCW direction of an arc, the machine looks at the plane of the circulation interpolation from the positive side of the third axis.
This means that the direction of the arc on the XZ plane will be decided when the machine looks at it from the positive side of the Y axis.
Since our viewing direction matches with the viewing direction of the machine on a rear-type lathe, CW or CCW direction also matches.
However, on a front-type lathe, the two viewing directions are opposite. Therefore, what is CW for the machine, is CCW for us, and vice-versa.
Hence, on a front-type lathe, we need to use G02 for a CCW arc, as perceived by us. Likewise, for G03.

The same principle is used for deciding the left/right direction (G41/G42) in radius compensation. One needs to look at the plane of compensation from the positive side of the third axis.

 

[angelw]

Still wondering about arcs though...

Its as Sinha explains, but to put it in quite lay terms, imagine that you took the rear turret machine, that you seem familiar with, and rotate the X Axis and Rear Turret about the Centre line of the spindle. Now the turret is at the front of the machine, the RH OD Turning Tools that were upside down at the rear are now top side up at the front and the X axis + direction is towards the operator standing at the front of the machine.

As well as the Turret and X axis Slide being rotated about the Centre Line, imagine that the operator at the front is also rotated around the centre line and is now upside down at the back of the machine. Its from that view point the direction of Tool Radius Compensation and Circular Interpolation is determined. Therefore, G42 with the Turret at the front of the machine will still be for an OD Tool on the OD of the Work-piece, traveling towards the chuck at the left end of the machine. Likewise, a Convex OD Radius will still be G03. You have to view the tool path looking up from the floor.

Regards,

Bill

 

[rainman]

Thanks Sinha and angelw. So, what I'm hearing is, if you're using CAD/CAM, you could program it just like it was a rear turret lathe. The code would be the same, it's just the perspective of the operator is rotated 180 deg. about the centerline. That makes it easy, in that I don't have to create a custom post that reverses everything.

 

[angelw]

Thanks Sinha and angelw. So, what I'm hearing is, if you're using CAD/CAM, you could program it just like it was a rear turret lathe. The code would be the same, it's just the perspective of the operator is rotated 180 deg. about the centerline. That makes it easy, in that I don't have to create a custom post that reverses everything.

Hello rainman,
That's absolutely correct.

Regards,

Bill

 

[Job Shopper TN]

Yep. I can use the same program on an SL20 or a TL2.

 

[rainman]

Beautiful. Thanks guys.