Changing Z-Height While Maintaining Y Velocity

I would like to perform multiple moves in the Z axis while maintaining a constant velocity along the Y axis. For example, I would like to be able to execute something similar to:
G1 X1 Y1 Z1
G1 Y3 Z1
G1 Y5 Z2

...without decelerating and then accelerating again in the Y direction.

Is this possible? I am using a Shopbot PRSalpha Buddy with a Mesa 7i76 board and LinuxCNC. I have tried using G64, but still get more acceleration along Y than I would like.

Thanks!

Yes, although it's a nonstandard torch for which the typical voltage-based adjustments will not work. We plan to probe the surface to measure height changes.

That module does sound interesting. Do you know where I can find the original source code? The Gitweb link in the wiki is dead. I found an old compiled version on the forum, but I would prefer the source if possible.

Is there no simple G code means to avoid acceleration along one axis between commands affecting a different axis? The module seems like overkill for handling this, but maybe there is no simple solution.

Thanks!

As long as you are not set for exact stop mode, your code should give smooth motion in Y. You may have to experiment with the P and Q parameters of the G64 command to get the results you want.
See linuxcnc.org/docs/html/gcode/g-code.html#gcode:g61-g61.1
for more info.

Jon