[nicubila]

Hi all


I might be in search for smth already well documented, but for 2 days I was searching and nothing to clarify my problem: how to setup a 3 Axes, 4 motors router/mill?

It is strange that there are quite a few posts but none seems to provide such a manual. Moreover, I am sure that a very high percentage of people use this type of setup for their routers - and still no such detailed documentation.

I am now with mach3 and decided - for many reasons - to switch to linuxcnc. I will drop the smoothstepper as well, to get to linuxcnc - in the hope it will work. But so far I had been just confused.

I know that I have to start with the stepper_mm which is the preconfigured setup for this. But what to do next? I am really not an experienced cnc user, but the setup should be for those like us as well. I want to have my cnc setup and running, not learn all the complex linux tricks.

Sorry for being so pushy, but I am quite frustrated with the effort and no results.


Best
Marius

[alan_3301]

Say you have 2 drivers and motors for 1 axis.
You have the drivers wired to different pins on the parallel port.
When you run stepconf to set up your configuration, you can set Y step/direction to 2 different sets of pins. you will have to invert direction on one pin to get the motors to spin in opposite directions and not fight itself/twist the gantry.

Look at the image I posted.. It has Y step/direction on pins 4 and 5
instead of A step/direction on pins 8 and 9, change A to a second occurence of Y on 8 and 9, with invert clicked on pin 9.

[nicubila]

Thanks alan


I see.
I have ballscews on my router, so both the motors on the Y and A axes (A slave to Y) will move same direction.

Will this config work with an independent homing? I have limit switches on both Y and A, and i MUST square the gantry for my application. Is there any further change I have to do for this?

Thanks
Marius

[alan_3301]

If you want to do independent homing of slaved axes, you need to run a special config called gantry-kins
I don't have any direct experience with it. I was going to try and figure it out, but havent found the need to home both motors yet.
Sadly there are no step by step guides, but if you figure it out, maybe you could post one.

Start with reading this thread. LinuxCNC Support Forum :: Topic: implementing gantrykins (1/4)

[nicubila]

kind of not really solved. strange how there is no solution for this though I assume so many have this config.

I promisse I will make a doc file if i find how to do it.

[cmitcham]

kind of not really solved. strange how there is no solution for this though I assume so many have this config.

I promisse I will make a doc file if i find how to do it.

i completely agree that this almost standard setup is poorly documented. even the reply you got above, while seemingly knowledgeable, doesn't help. the attached picture does not show anything other than the default screen.

i sure hope you figure it out soon, i'll be anxious for your results. i'll keep trying too and post any success here

[nicubila]

with the risk of anoying someone, I have to say that from outisde the "power of linux" seems much more consistent than from inside - once you made the first steps, feels like being lured with a candybox, then lost in ini files.
I did not expect a plug'n play solution, but neither a hassle.

One cannot despise a Mach3 user for not jumping into the linux boat. The gap between the 2 boats is too big in terms of having setup the system. I have my router for 2 years now but the complexity for having my system working in linux seems to high. I don't even have an idea of how much time would take to learn all the tricks for making it work.

To conclude in a more positive note: I can bet that if a couple of ready-made solutions are documented step by step, there will be a significant number of people making the switch and benefiting from linuxcnc. A simple 2 pages step by step quide should be enough to document simple setups like 3 axes 4 motors (or joints). Such standard guides will be the candy that will really turn on a lot of people.


Marius

[cmitcham]

so i kept re-reading alan's answer above, and i finally understand what he said from the beginning. it works! attached p port setup screenshot shows the answer...

thanks alan!

[109jb]

with the risk of anoying someone, I have to say that from outisde the "power of linux" seems much more consistent than from inside - once you made the first steps, feels like being lured with a candybox, then lost in ini files.
I did not expect a plug'n play solution, but neither a hassle.

One cannot despise a Mach3 user for not jumping into the linux boat. The gap between the 2 boats is too big in terms of having setup the system. I have my router for 2 years now but the complexity for having my system working in linux seems to high. I don't even have an idea of how much time would take to learn all the tricks for making it work.

To conclude in a more positive note: I can bet that if a couple of ready-made solutions are documented step by step, there will be a significant number of people making the switch and benefiting from linuxcnc. A simple 2 pages step by step quide should be enough to document simple setups like 3 axes 4 motors (or joints). Such standard guides will be the candy that will really turn on a lot of people.


Marius

I have had the exact opposite experience. I set up my 3 axis mill in LinuxCNC the first time in about an hour after installing the software using the LinuxCNC getting started guide. I then added home/limit switches to my current mill and it took about 3 minutes to do the configuration for that.

I decided to give Mach3 a try and spent about 3 hours trying to get it to run right and I still don't have it working satisfactorily. I will get it there and will give Mach3 a fair tryout, but so far I still like LinuxCNC better. Too many cartoonish screens in mach3 for my taste and too hard to find what I want to do.

[alan_3301]

cmitcham: glad you got it working. Sorry if my first post was hard to understand.
As nicubila said, if your motors are supposed to turn the same direction (as in dual lead/ballscrews) then don't check invert.
If you have rack&pinion drive like me, and the motors face is opposite directions, then you must leave it checked.


nicubila: I am in the process of making home switches for my Y axis, so I can experiment with the gantry homing sequence.
It may be a while before I am finished (not much free time). But I will show what I had to do when I figure it out.


109jb: I'm with you. linuxcnc just felt natural to me, and the getting started guide and website docs are great.
I tried mach3 as some point and was put off by the 100 buttons on the same screen. The mach3 2010 screen looks like it fixed that, but I'm too invested in linuxcnc right now.