Homing / limits - the manual is misleading, possibly wrong

yep HOME_OFFSET= -25 sets 0 to 25mm from the limit switch
so HOME_OFFSET= -3 sets 0 3mm from the limit switch

is that not a reasonable choice ?
I know i have to add just the travel to make sure I can not hit the end stop because I am loosing 3mm form the total travel

C

There is nothing wrong with what you have if it works but if you want back the bit of travel...

I would try this:
MIN_LIMIT = -.01
HOME = 0

that should get you all the travel you can on the minimum side.
Then I would temporarily set MAX_LIMIT = 450
Then home the machine
it should be just off the negative limts and absolute machine position (not user coordinates ) should be zero

now jog until you hit the max limit switch or if you don't have a max limit switch then until you get maximum travel.
now check the machine position it will be close to 440 but probably a bit more.
If you you have a a max limit switch it needs to be slightly under this number.
say like .01 under

That will be your MAX_LIMIT in your INI.
And that should give you absolute maximum travel.

once linuxcnc is homed it's smart enough to de-accelerate before it hits the soft limits -so it will always stop right on the soft limit.

Of course I would test everything before I tried rapid-ing into the max soft limit.
Chris

sorry I got that wrong..hold on

i was about to change the setting and test.
holding on now

C

This is what I'm basing my suggestion on - i forgot to check before i spoke last post
I would just keep lowering :
HOME_OFFSET = -3
till I found the minimum that worked - it should be quite small though

then do the check for maximum travel as I said
If you got 443 for the max, then I would try 442.5 and then test

But like I said - we are almost splitting hairs..

Chris

1. thank you
2. I don't think we are splitting hairs. we are defining a process for dialing getting the max travel which is actually very useful in my opinion.

you have basically let me know I don't need the full 3mm of clearance I allowed for and even .1mm is probably fine. Every CNC machine I have worked on I have always run into a case at some point where I am like .5mm over the max travel and have tor redesign a part so MM matter

Thank You
Calvin