Re: Wierd Z axis in EMC

TimS

The retro sounds great. Good luck with its completion.

Which version of the BDI? Is this a download? If yes, did you run the
checksum? How many axis defs do you have in the ini?

I've not heard of a problem like this and I can't imagine where in the
freqmod module it might be. Normally freqmod starts up with a maximum
permitted frequency that is a calculation based on MAX_VELOCITY, UNITS, and
INPUT_SCALE.

I don't run with an mm definition here and I've heard of some setup
nightmares and been party to a few myself. First be certain that you have
commented out or removed or changed the line (about number 22) in the ini
that says.

; Startup codes for RS-274-NGC interpreter
RS274NGC_STARTUP_CODE = G20

You want the interpreter to default to G21. It will do that with nothing in
the ini or change this line to read G21.

Other things to look for include

[TRAJ] LINEAR_UNITS should be set to 1.000

[AXIS ?] UNITS should be set to 1.000

You need to multiply the default

FERROR = 1.000
MIN_FERROR = 0.010

by 25.4.

I run [TRAJ] MAX_VELOCITY a bit higher than I set the same variable for each
axis. In the case of 188 mm/min I'd start out with the traj one to 3.25 or
more and each axis to 3.13.

Keep talking.

Ray

>    From: "smith67au" <thdsmith@...>
> Subject: Wierd Z axis in EMC
>
> Hi guys,
>
> I have installed BDI EMC recently.
> I just got it going OK I thought, but now seems to have gone off the
> rails.
>
> I have a Bridgeport mill (which I am in the process of completing
> it's conversion to CNC),and am running steppers using freqmod, on a
> 300Mhz 64Mb M/c.
> The drivers I am using are old STM103 (Superior Electric, I think)
> cards.
>
> The was machine running OK, and then without making any changes the Z
> axis has gone mad.
> When I try and jog the Z(say 180mm/min), it takes off at higher than
> the max speed my setup is able to run at(ie. motors stall and get
> following error). If I then reset the machine and try and jog the X
> or Y, I get the same result, but if I haven't tried to jog the Z the
> X and Y work as expected.
>
> This is only a problem with EMC, as if I reboot in dos, the other CNC
> programs(DeskncRt, TurboCNC) I have still work OK.
>
>
> I am going to try another PC, as the one I have does have some
> problems with the System Registry when loading Windows, I don't know
> if this indicates a fault that would affect Linux/EMC..
>
> Does anyone have any other suggestions that may be causing this
> problem?
>
> Any help would be appreciated.
>
> Thanks
> Tim Smith