Re: individual velocities

[Jon Elson <jmelson-at-artsci.wustl.edu>]

Matt Shaver wrote:

>
> Anyway, maybe another solution would be to specify (in the .ini file) the
> velocity to use for G0 moves for each axis, and to stop interpolating G0
> moves. I think Fred has this issue on his "things to do" list, but I'm not
> sure what his current thinking is about how to handle this issue. As far as
> acceleration goes, I don't know what amount of work on the motion system
> would be required to implement per axis acceleration values.

Actually, there is a better way to do this, and leave interpolation on.
You see what the desired feed rate is, and compute the necessary rate
on each axis.  That is done already.  If the feed on any axis exceeds
that axes' maximum feed rate, you scale all feeds down by the ratio
that axes' rate was exceeded, and you now have a feed rate that will
not overtax that axis.  No excessive following error will be generated,
multi-axis moves will still be interpolated cleanly.  Moves on faster
axes only will still be allowed to go as fast as the affected axes can move.

This seems to be the ideal solution, and I think only needs for the
trajectory planning to know what all axes' max feeds are, and it
can do this with about 4 lines of code.  This is effectively similar
to doing a feed rate override to prevent overtaxing a slow axis.
Should be quite simple.

Not a problem for me directly, until I put a rotary axis on my machine.

Jon