Getting started with Linux, LinuxCNC and CNC

Well, my basic machining knowledge is rather good, but when it comes to cnc I am aware I suck. I want to learn, but its hard to do when you get into the airplane, and instructions say "this is a stick, those are the flaps and rudder, there you go, fly"

Have you looked here?
gnipsel.com/linuxcnc/g-code/index.html
and
forum.linuxcnc.org/forum/lathe-subroutines-library

Start linuxcnc
under sim.axis.ngcgui
There should be a sample config included with linuxcnc called
ngcgui_lathe

You might want to try that.
To keep things simple to start with you might want to just touch off with your current tool and worry about the tool table later.

You can run your lathe without home and limit switches. A simple set up could be to have a home position with Z at the end of it's travel (all the way to right) set to 0 and X all the way out (toward the operator) set to 0.
If you home the X and Z axis there and you have configured the correct amount of travel for your machine the "soft limits" should take effect.
So you would home the machine, then jog to your work piece, then touch off to the work piece. The link above shows one method.
When done working a command such as
G0 G54 X0
should return the X to home position and
G0 G54 Z0
Should return the Z to it's home position.

First steps first are your configuration files correct for your machine? If not we can help you set them up.

Rick G

OK, its been some really tough days for me, trying to figure out what to do next, should I just drop everything, or go to some modern electronics stuff and use different software - that others around me use. But I thought to give this another go.

I ve read a lot of tutorials and watched a lot of videos in the meantime, but my knowledge is still at very low bases. In a lot of cases, I cant even understand what the tutorial is trying to say due to terminology used, that I am really unfamiliar of - that would be an easy task 20 years ago when I started using computers, but today, its really hard and time consuming to even get to that. And everyone here uses Windows - trust me no linux users that could help out.
Just like I said on another forum, I am ready to learn, but this has to be really step by step and line by line explanation - click exactly here, type exactly this here etc, for me to get a hang of it. I used to be a banker, and I have managed to learn how to operate manual lathe and mill, with tutorials and a help from people that had the right "this one is a noob" aproach.

The files found here are correct for my setup - thanks to samco. Only it would be nice to have them in metric instead of inch measurements - I would like to know how to make that work.

Also, I ve found this forum.linuxcnc.org/forum/40-subroutines-...-of-ngcgui?start=310
it looks just like something that I need! I ve read the instructions and managed to get it as standalone, but no luck with embeding it to axis, because the further I read what had to be done, I got more confused.

github.com/cnc-club/linuxcnc-features

I ll continue to run my lathe without switches, and from what I can see in operation, it has some sort of homing set up in the files from samco (also, I cant tell how they are configured, but the carriage and cross slide take a spot in the middle - in both ways). Using touch off seems like a good way to deal with things, especially when one has different lengths of stock in use, but with primarily parting and hopefully threading operations, setting tool offsets from the master one would be a large step forward.
I really do hope that you are willing to help me out.
Thanks
Stefan

Thank you, that was very informative! I used View->Display MM but I wasnt sure that it will affect some future g code that might contain imperial units.
Thanks again

Have you tried the sample ngcgui lathe simulator configuration that is included with linuxcnc that I mentioned above?
It includes subs for inside diameter, outside diameter, taper, etc. and there are more subs available.

Rick G

Actually I did, if it was the correct one - took me some time to find it in there. I just wasnt able to generate code (probably didnt see the correct interface button in there) but I will give it a try again.
Also a major setback is not having internet connection in those workshop comouters, so I cant read and try it in live mode at the same time - but that is beeing taken care off.

Aaaah, found the one you meant. Its pretty good from what I can see, for simulation purposes.
I believe I cant embed its features into my lathe configuration that I choose when I start linuxcnc?



First try, but without the usage of ngcgui or simulator. OK, threaded air first, then some acetal, than aluminium.

I preprared the piece of material to be 0.5 OD (and jaws are as good as new so no runout), touch of x and z and in mdi gave the g0 x1 z0.2 command, then the following g76. it warned me that I should turn on the spindle (M3) and I did prior to this type in a g7, g18 and g20 just to be sure what I am doing - for lathe plane, imperial units, diameter mode (just cant use radius )

the g76 i wrote by hand at first G76 p0.05 z-1 i -0.5 j 0.005 r2 k 0.02975 q 29.5 h 2 e 0.02975 l3, but later I changed the K to 0.075 , put the R to 1 H to 0, E is same as K and L0, to get it to do this faster. it took ages with the first line of code. And I set spindle speed at 550, its quite steady. I hope this wasnt too fast? I have to get to the bottom of these R, H and L , and also to find a proper table for depths of cut for the threads - used 0.075 was a pure estimate ( in some tables I found that minor diameter should be 0.46** something, I subtracted that from 0.5 and divided by 2 at first, way too shallow lol, then I just used the 0.5 minus minor diameter, that was too shallow too - perhaps I am using the wrong lines in those tables?)

Looks like you are making progress.

I just wasnt able to generate code (probably didnt see the correct interface button in there) but I will give it a try again.

With ngcgui
Select the operation you want.
Fill in the fields
Then hit "create feature"
Then hit "finalize"
The operation should be created and take you back to linuxcnc where you can view and run the program.

Also note that after you hit "create feature" you can select another operation, fill in the fields, create next and then finalize and both operations will be combined one after the other for as many as you select. So you could run outside diameter, then taper and run them together.

You can add ngcgui to your configuration and select other operations to be listed in the tabs at top. You can also create your own.
If you get comfortable running ngcgui on the simulator we can help you modify your working configuration to add ngcgui.

Rick G

Thanks, I will give it a try for sure! And get back to you.