Hallo Dewey,
thanks for your very detailed explanation, most of that is known, but I
still do not understand why that have been changed, as it does not
change any behavior, it just makes thinks more difficult for users, used
to have the same INI settings for several updates.
I have the impression that someone changed that long time ago, maybe
even by mistake and it has just in there.
Sorry for my very slow understanding ;-)
It means, that I may have to change some more code in gmoccapy files :-(
only because a known standard has changed.
By the way, have you seen my new branch gmoccapy_JA?
I will inform as soon as it is mergable to JA. I still miss the
modification of the homing and jogging buttons. And find a way to handle
the differnt modes if a user uses Jogwheels or hardware button.
Norbert
Am 22.06.2016 um 18:52 schrieb Dewey Garrett:
> The specification of velocities (and accelerations) is
> confusing because of the multitude of ini settings available
> in the [TRAJ], [AXIS_ll], [JOINTS_nn], and [DISPLAY] sections
> of an ini file. Extra complications may occur because the
> interpretation of items in the [DISPLAY] section may be
> GUI-dependent.
>
> Note that default values are silently applied (typically from
> src/emc/nml_intf/emccfg.h) when not otherwise specified and
> the defaults may not be applicable to a given machine. The
> default values seem to be biased to machines with imperial units.
>
>> Imho MAX_VELOCITY is the correct nomination, as a circular
>> move may invoke several axis, is not linear
> The axis letters X,Y,Z typically specify linear coordinates
> and may be limited by trajectory planning according to
> [TRAJ]MAX_LINEAR_VELOCITY.
>
> For instance, in joints_axes branches, the velocity of a gcode
> arc move (g2/g3) using x,y coordinates obeys the F number rate
> OR is limited to the smallest value allowed by:
>
> 1) individual [AXIS_n]MAX_VELOCITY limits
> or
> 2) [TRAJ]MAX_LINEAR_VELOCITY
> or
> 3) feed override setting
> or
> 4) maybe other items i don't know about
>
> The [TRAJ]MAX_LINEAR_VELOCITY applies because a g2/g3 movement
> is for linear coordinates (x,y,z).
>
> If a rotary coordinate (typically A,B,C) is specified with g2
> or g3, then the rotary travel is coordinated to end when the
> x,y,z motion ends. As noted in the documentation for g2/g3,
> "Lines of this sort are hardly ever programmed" It is more
> common to use inverse feed rate mode (g94) when combining
> linear and rotary moves.
>
> To my knowledge, there is currently no non-gui code that uses
> [TRAJ]MAX_ANGULAR_VELOCITY nor [TRAJ]DEFAULT_ANGULAR_VELOCITY:
>
> $ cd my_git_root/src
> $ find . -iname '*.*c' -exec grep -EH MAX_ANG\|DEFAULT_ANG {} \;
> $ (nil)
>
> The use of [TRAJ]MAX_LINEAR_VELOCITY and [TRAJ]DEFAULT_LINEAR_VELOCITY
> was implemented long ago (cdc073dc6) in the joints_axes branch (I
> suppose) as preparation for future inclusion of trajectory angular
> coordinate settings should support for these be undertaken.
> Accordingly, these future settings would be named
> [TRAJ]MAX_ANGULAR_VELOCITY and [TRAJ]DEFAULT_ANGULAR_VELOCITY.
>
> (Note, some guis do currently use [TRAJ]MAX_ANGULAR_VELOCITY and
> [TRAJ]DEFAULT_ANGULAR_VELOCITY. For instance, the axis gui
> uses these items as candidates for setting jog slider start
> and limiting values.)
>
> -----------------------------------------------------------------
> I verified some comments above using a simple ngc file:
> #<fcirclerate> = 10000
> f10000
> g0x10y0z0a0
> f#<fcirclerate>
> g2i-10 a100
> g0x10y0z0
> m2
>
> and experimented with settings for #<fcirclerate> and the ini
> settings for [TRAJ]MAX_LINEAR_VELOCITY and [AXIS_nn]MAX_VELOCITY.
> For the ini items, it is convenient to use sim_pin, for example:
>
> $ sim_pin ini.traj_max_velocity \
> ini.x.max_velocity \
> ini.y.max_velocity &
>
> (Changes to ini.N.max_velocity values must be made when a
> program is not running)
>
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