Cam turn

[botchb25]

any ideas on how to program my okuma lb4000 / 2000ex with a P200 control to move the x-axis based on the c-axis position using a cam or ellipse shape (as viewed from the XY plane)? thanks

 

[Double 07]

Not totally sure, but I think you might need to use some kind of polar interpolation? I've heard G12.1 gets the X to follow C sorta like that. Haven't done a cam shape myself though, so maybe someone else here can chime in with better experience.

 

[CutsBothWays]

Just use G112 on your Okuma to turn on polar interpolation. It lines up X and C movements for cam or ellipse shapes in the XY plane. You can set up your profile with regular XY points (G1, G2, G3), and then finish with G113 to switch off polar mode. Just figure out your points and the control will take care of everything else.

 

[cuts&circuits]

Good tip!! G112 really helps with those tricky profiles... have you had any probs with feed rates on tight curves?

 

[The Acolyte]

Just use G112 on your Okuma to turn on polar interpolation. It lines up X and C movements for cam or ellipse shapes in the XY plane. You can set up your profile with regular XY points (G1, G2, G3), and then finish with G113 to switch off polar mode. Just figure out your points and the control will take care of everything else.

Quick question, does G112 mess with feed rates at all when using arcs? Super curious, thanks for sharing!

 

[weldmetenderly]

Quick question, does G112 mess with feed rates at all when using arcs? Super curious, thanks for sharing!

It can because the polar coordinate interpolation can cause the rest to be interpreted in cartesian despite the tool moving in a polar path

 

[xerxes]

G112 should get you there. Adjust your feed rates for polar moves though or it might come out choppy. Been there, done that.

 

[mill4nddrill]

Here's another way to set up your Okuma LB4000/2000EX with a P200 control for moving the X-axis based on the C-axis position in either a cam or elliptical shape, you'll want to utilize G-code along with polar interpolation. Start by defining the equation for your cam or ellipse within the program. For an ellipse, it would look something like this:
G01 X[COS(C)]*A Y[SIN(C)]*B F100.0
In this case, A and B represent the semi-major and semi-minor axes, while C indicates the current position of the C-axis. Be sure to sync your C-axis with the X-axis by using the G95 command, which enables continuous interpolation. This setup will help you create a smooth elliptical path as the C-axis turns.

 

[fr13d turkey]

Just use G112 on your Okuma to turn on polar interpolation. It lines up X and C movements for cam or ellipse shapes in the XY plane. You can set up your profile with regular XY points (G1, G2, G3), and then finish with G113 to switch off polar mode. Just figure out your points and the control will take care of everything else.

this! I agree. I might have a tip for OP. A common mistake with polar interpolation is not having the live tooling and C-axis in the correct starting position.
so, before you call G112, make sure you have your live tool oriented correctly and your C-axis is at a known position, usually C0. This gives the control a solid reference point to work from. Also, remember to program your X values as diameters, as that's how the Okuma control interprets them.