Can I run axes at different ipm on the same pass?

[yorttroy]

On my diy 3 axes router I used ¾ steel rod for the x axes, way too small. When the y axes is above 25 ipm the gentry starts to shake. I have had the x axes up to 40 ipm with no problems, but I can’t add a load or keep it at that speed long enough to determine if Turbo CNC can make the adjustments between 25 ipm on the y and 40 ipm on the x. My question is can I run the x and z axes at 40 ipm and the y at 25 ipm, will Turbo CNC allow the router to go faster on the x axes and slow it down for the y axes? I am running Desk Proto for my cam and it won’t allow me to adjust ipm for each axes. In order for me to run at a higher ipm on the x and z axes I will need to get new lead screws with a lower tpi and/or get larger steppers, but I don’t want to put in the extra time and cost if my y axes causes the whole machine to run at a slower speed.

[CJL5585]

Originally Posted by yorttroy My question is can I run the x and z axes at 40 ipm and the y at 25 ipm, will Turbo CNC allow the router to go faster on the x axes and slow it down for the y axes?

In the TurboCNC setup menu there are settings for start speed, acceleration, and Max speed settings. These settings are entered for each axis. If you set the max speed for the Y axis at 25 inches per minute, (or mm per minute), TurboCNC will adjust (or control) the speed of the X and Z axis to compensate for the lower speed on the Y axis as necessary.

I am still running the old version of TCNC and do not use version 4.

Jerry

[yorttroy]

Originally Posted by CJL5585 In the TurboCNC setup menu there are settings for start speed, acceleration, and Max speed settings. These settings are entered for each axis. If you set the max speed for the Y axis at 25 inches per minute, (or mm per minute), TurboCNC will adjust (or control) the speed of the X and Z axis to compensate for the lower speed on the Y axis as necessary. I am still running the old version of TCNC and do not use version 4. Jerry

Thanks for the info I set it up at different axes speeds and it compensated for the different axis speeds.

I am also running the old version of TCNC, it works just fine and I never saw any reason to upgrade.

[CJL5585]

Originally Posted by yorttroy Thanks for the info I set it up at different axes speeds and it compensated for the different axis speeds. I am also running the old version of TCNC, it works just fine and I never saw any reason to upgrade.

I like the old version better than the newer version. Seems like they made it a lot more complicated than it had to be.

Jerry

[mcmmach]

Originally Posted by yorttroy On my diy 3 axes router I used ¾ steel rod for the x axes, way too small. When the y axes is above 25 ipm the gentry starts to shake. I have had the x axes up to 40 ipm with no problems, but I can’t add a load or keep it at that speed long enough to determine if Turbo CNC can make the adjustments between 25 ipm on the y and 40 ipm on the x. My question is can I run the x and z axes at 40 ipm and the y at 25 ipm, will Turbo CNC allow the router to go faster on the x axes and slow it down for the y axes? I am running Desk Proto for my cam and it won’t allow me to adjust ipm for each axes. In order for me to run at a higher ipm on the x and z axes I will need to get new lead screws with a lower tpi and/or get larger steppers, but I don’t want to put in the extra time and cost if my y axes causes the whole machine to run at a slower speed.

The speed each axis travels at is determined by the max ipm on the slowest axis and the distance each axis has to travel.

In your case if X=40 ipm and Y=25 ipm and you did a G01 X20.0 Y20.0 F40.0 command both axis would move at Y's max 25 ipm.

If you did a G01 X40.0 Y20.0 F40.0 command then X would move at 40 ipm and Y would move at 20 ipm so that both axis arrive at the correct point at the same time.

Hope that helps a little.
Dean

[HuFlungDung]

Actually, I believe that the feed is usually calculated as 'feedrate along a vector', and if the vector is along one axis, then that axis has the full feedrate. If the endpoint requires a two or three axis movement, then the actual velocity vector has to be broken down into its components for each right angle axis. This way, the total combined vector velocity of the component vectors, will never exceed the commanded feedrate.

That sounds more technical than it should but that's how it works. That's what a lot of that high school physics was about.

It is best to keep the maximum feedrates of X and Y the same, for the sake of circular interpolation. The control may automatically cap the feedrate at that of the slowest axis anyways, so you might as well just put that in the controller setup, rather than kidding yourself that you will make time on the faster axis.

For rapid movements, you can specify whatever you like for a max velocity for each axis, as interpolation is not a strict requirement for rapid moves.