How to MPG Jog before homing?

More
20 Oct 2020 02:03 #186643 by jhandel
I would like to be able to use my Pendant before homing the machine.. Because my limit switches are past my homing switches it is possible to be in a place where homing first may be a bad idea and jogging a bit before homing is wise.

So, yah.. what HAL config should I be doing to allow my pendant/MPG to jog the axis before they are homed?

Thanks in advance.

FYI: Here is my MPG.hal which works great :) (Axis A & B will be configured after I get the basic XYZ worked out )
setp jogincr.in1 0.00025
    setp jogincr.in2 0.0025
    setp jogincr.in4 0.025
    net mpgscale1 jogincr.sel0  <=  hm2_7i76e.0.7i76.0.0.input-22
    net mpgscale2 jogincr.sel1  <=  hm2_7i76e.0.7i76.0.0.input-23
    net mpgscale3 jogincr.sel2  <=  hm2_7i76e.0.7i76.0.0.input-24

    net pend-scale  <=  jogincr.out
    net pend-scale  =>  axis.x.jog-scale
    net pend-scale  =>  axis.y.jog-scale
    net pend-scale  =>  axis.z.jog-scale

    net mpg-x <= hm2_7i76e.0.7i76.0.0.input-17
    net mpg-x => axis.x.jog-enable
    net mpg-y <= hm2_7i76e.0.7i76.0.0.input-18
    net mpg-y => axis.y.jog-enable
    net mpg-z <= hm2_7i76e.0.7i76.0.0.input-19
    net mpg-z => axis.z.jog-enable
    #net mpg-A joint.3.jog-enable <= hm2_7i76e.0.7i76.0.0.input-20
    #net mpg-B joint.4.jog-enable <= hm2_7i76e.0.7i76.0.0.input-21

    net pend-counts <= hm2_7i76e.0.encoder.09.count
    net pend-counts => axis.x.jog-counts
    net pend-counts => axis.y.jog-counts
    net pend-counts => axis.z.jog-counts

Please Log in or Create an account to join the conversation.

More
20 Oct 2020 02:14 - 20 Oct 2020 02:15 #186644 by rodw
Replied by rodw on topic How to MPG Jog before homing?
The intended use is for the Home switch to remain triggered all the way to the limit switch then Linuxcnc can work out where it is in relation to the home switch at the start of homing and back off to find the home trigger point before commencing homing proper...

So I would recommend you sort that out.
Last edit: 20 Oct 2020 02:15 by rodw.

Please Log in or Create an account to join the conversation.

More
20 Oct 2020 18:44 #186723 by jhandel
May be harder than all that because this is a retrofit so I can't just easy move where the limit and homing switches are.. the designer (for what ever reason) decided that the home switches should be a good 20mm away from the limit switches..

Please Log in or Create an account to join the conversation.

More
20 Oct 2020 18:59 #186726 by Mike_Eitel
You could use a makro to move to a suitable position before shutting down lcnc

Please Log in or Create an account to join the conversation.

More
20 Oct 2020 21:07 #186752 by rodw
Replied by rodw on topic How to MPG Jog before homing?

May be harder than all that because this is a retrofit so I can't just easy move where the limit and homing switches are.. the designer (for what ever reason) decided that the home switches should be a good 20mm away from the limit switches..


Thats not unexpected and in fact, I think its desirable. I would not move the switch. Can you extend the home switch striker plate from where it ends now to the limit switch?

Please Log in or Create an account to join the conversation.

More
21 Oct 2020 01:49 #186779 by jhandel
my main consern was if I got "stuck" due to something going bad I wouldn't be able to move my way back past my home switch (its on the ++ side so if I am past it and I lose power/etc then Linux CNC won't let me go negative.. )

I learned about the POSITION_FILE setting this evening.. That gives me what I really need.. sure the machine doesn't stay homed between boots, but this will let me get out of a sticky situation if something horrible happens..

Please Log in or Create an account to join the conversation.

More
21 Oct 2020 02:38 #186784 by JohnnyCNC

You could use a makro to move to a suitable position before shutting down lcnc


This basically what I do. I used a G28.1 to store what I call the park position where my table is centered in the X & Y. I added a button that issues a G28 that I use before shutdown. However my USB connect P4-S pendent does allow me to jog before homing.

Please Log in or Create an account to join the conversation.

More
21 Oct 2020 05:23 #186788 by rodw
Replied by rodw on topic How to MPG Jog before homing?

my main consern was if I got "stuck" due to something going bad I wouldn't be able to move my way back past my home switch (its on the ++ side so if I am past it and I lose power/etc then Linux CNC won't let me go negative.. )


Thats not how it works if you set the homing up according to the docs. All you would do is home hte mchine again, Linuxcnc would see the home switch is triggered and move back offf it and commence the homing cycle.

Trust the Linuxcnc paradigm! If you don't then find another controller you can trust!

Please Log in or Create an account to join the conversation.

More
21 Oct 2020 11:24 - 21 Oct 2020 11:25 #186802 by jhandel

Thats not how it works if you set the homing up according to the docs. All you would do is home hte mchine again, Linuxcnc would see the home switch is triggered and move back offf it and commence the homing cycle.

Trust the Linuxcnc paradigm! If you don't then find another controller you can trust!


Its an inductive switch so make a block long enough that it stays triggered by home even when I am at my machines hard limit, then linux CNC will roll backwards off of the block until it turns off then seek it again....

I'll probably have to machine that block once the machine is running... but its doable...

For now having positional file is enough to get me out of a sticky whicket while I am programming & configuring the machine
Last edit: 21 Oct 2020 11:25 by jhandel.

Please Log in or Create an account to join the conversation.

More
21 Oct 2020 14:40 #186813 by rodw
Replied by rodw on topic How to MPG Jog before homing?
Now you are talking. I welded mine up. but machined some slots for adjustment. Described on P1 of my build thread
forum.linuxcnc.org/show-your-stuff/32029...cutter-build?start=0

Please Log in or Create an account to join the conversation.

Time to create page: 0.509 seconds
Powered by Kunena Forum