PlasmaC Z axis following error

I can't seem to find out where the error is coming from with the Z axis.

I only seem to get this when a program in running and I hit stop. The Z start to move up then error.

It is fine when hitting pause. And jogging up and down is no problem.

I have tried various values of MAX_VELOCITY and MAX_ACCELERATION etc

The motor is a nema 23 with a 5mm ball screw

I know PlasmaC take care of the Z axis but can't see it making any difference than normal control

Change the max and min travel to positive values, min can be a nit on the negative but preferably not under -20.
And you have max_velocity and max_acceleration twice there, delete the second set.
Also change the homing and offset to reflect the changes in workspace.

[AXIS_Z]
......
MAX_ACCELERATION = 800
......
STEPGEN_MAX_ACC = 500


I would change STEPGEN_MAX_ACC to 1000 and try again

tommylight wrote: Change the max and min travel to positive values, min can be a nit on the negative but preferably not under -20.
And you have max_velocity and max_acceleration twice there, delete the second set.
Also change the homing and offset to reflect the changes in workspace.

Tom I noticed for the first time that the limits are not the same in the two sections.. ie min limit -72 and -82

Clive S wrote:
Tom I noticed for the first time that the limits are not the same in the two sections.. ie min limit -72 and -82

That is not very important as it will work even that way.
But they have to be positive values for PlasmaC, so 72 or 82mm, whatever your machine can do in Z travel.
That is also where the home should be. PlasmaC uses reverse values for Z axis, or i should say PlasmaC uses real life values for Z, not the reverse as mills do. So the upper limit 82, lower limit 0 or thereabouts.

Can you please give me a sanity check re:

[AXIS_Z]
MIN_LIMIT = -82
MAX_LIMIT = -4

# set to double the value in the corresponding joint
MAX_VELOCITY = 60
# set to double the value in the corresponding joint
MAX_ACCELERATION = 800
# shares the above two equally between the joint and the offset
OFFSET_AV_RATIO = 0.5

[JOINT_1]
AXIS = Z
MIN_LIMIT = -82
MAX_LIMIT = -4

MAX_VELOCITY = 30
MAX_ACCELERATION = 400

TYPE = LINEAR
SCALE = -800

STEPGEN_MAX_VEL = 37.5 (Is this line required as the docs call it STEPGEN_MAXVEL but says it is not required)
STEPGEN_MAX_ACC = 500 ( Is this spelt correct as the docs call it STEPGEN_MAXACCEL)

I am trying to sort out a problem with Z following error only on hitting the stop button when the Z start going up pause is fine.

Peter suggested that I try changing STEPGEN_MAX_ACC = 500 to 1000
But I would like to make sure the format in the INI file above is correct as the name is the PlasmaC sim are different

AFAIK it is STEPGEN_MAXACCEL

STEPGEN_MAXVEL is not required

phillc54 wrote: AFAIK it is STEPGEN_MAXACCEL

STEPGEN_MAXVEL is not required

Thanks Phill so if I have it spelt wrong (might be from 2.7) the numbers I have been changing might not be being used !!

I will alter them and see what happens. The Z seems to work fine re: the limits are they OK as min and max being -ve as I have them

You mentioned dropping back to 2.8 how is that achieved ?

Edit
I have just looked in the HAL file and it is pointing to the same names
setp hm2_[HOSTMOT2](BOARD).0.stepgen.01.maxvel [JOINT_1]STEPGEN_MAX_VEL
setp hm2_[HOSTMOT2](BOARD).0.stepgen.01.maxaccel [JOINT_1]STEPGEN_MAX_ACC

so I will have to change those as well

Oh, you must have used that off-site configuration tool rather than Pncconf

Just follow this procedure:
linuxcnc.org/docs/2.8/html/plasma/plasma...u_have_linuxcnc_v2_7
from this line:
"Close the terminal, then from the Main Menu, open Synaptic Package Manager"
of course you wouldn't have a terminal open so you won't need to close it.

Phill I would like to do a fresh install of 2.8 I have an ISO for that.

Can I just copy my config folder to the new install and is it possible to go back to PlasmaC V0.123