A little surprised at the lack of activity.

joel0407
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25 Jul 2017 21:47 #96427 by joel0407

Replied by joel0407 on topic A little surprised at the lack of activity.

grump wrote:
I visit this board 3 or 4 times per day, often a lot more and read all new posts in the threads I have interest.
I also use 2.8 and have since it first appeared. I enjoy testing and bug searching (sad old man).
I do a fresh install probably 2-3 times a month to keep up with the latest developments and test them on my machine.
I only comment when I think I can help or need it and I think that's why people come here (for help).
If we all partook in inane chit chat the board would soon fill with it and make assistance harder to find.
The search facility is excellent, the answer to a given problem can often be found without asking.

I have a small 3 axis 3020T in a spare bedroom to which I have added a fourth axis and do lots of rotary engraving (military logos / insignia on spent shell cases).

There my contribution to the inane chit chat for what it's worth

I agree.

I was about to say "I'm surprised the forum doesn't have an off topic section. Most forums do." then I checked before I posted this.

Whoops. Maybe a Mod could move it for me.

Happy Days

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jmelson
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27 Jul 2017 02:09 #96522 by jmelson

Replied by jmelson on topic A little surprised at the lack of activity.

Does that mean everyone who uses LinuxCNC just uses a pretty generic setup which it just works

No, there are LOTS of non-generic machines out there. serial kinematics robots, hexapods, delta machines, non-traditional CNC stuff like wire and pipe benders and a CNC silkscreen printer. There are 5-axis CNC mills with multi-axis corrections for various misalignments in the machine. And, several pick and place machines.

I have a traditional 3-axis servo-controlled mill with a jog pendant, a Blum touch probe, and do a lot of rigid tapping with it.

As for the 2 motors on one axis, we now have gantrykins, which standardizes the homing problem.

Jon

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rodw
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27 Jul 2017 02:21 #96526 by rodw

Replied by rodw on topic A little surprised at the lack of activity.

jmelson wrote:

Does that mean everyone who uses LinuxCNC just uses a pretty generic setup which it just works

As for the 2 motors on one axis, we now have gantrykins, which standardizes the homing problem.

Jon

But gantrykins is now obsolete (from v2.8) :ohmy:

I hesitate to use the term joint axis which replaced it. To me thats not really a good description. Its more that LinuxCNC has separated joints (eg. motors) from axes to add even more flexibility. Says the noob who has only used V 2.8 with its separated joints to drive my gantry.

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jmelson
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27 Jul 2017 04:13 #96530 by jmelson

Replied by jmelson on topic A little surprised at the lack of activity.

Right, I'm always behind the times. But, I think 2.8 includes the functionality needed to allow the two sides to home partially independently, and then move in unison once both sides are homed. And, I just know this has been a problem in the past for some users, and don't actually know how to do it. I didn't find any Wiki articles on gantry homing.

Jon

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rodw
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27 Jul 2017 04:34 #96532 by rodw

Replied by rodw on topic A little surprised at the lack of activity.

jmelson wrote:
Right, I'm always behind the times. But, I think 2.8 includes the functionality needed to allow the two sides to home partially independently, and then move in unison once both sides are homed. And, I just know this has been a problem in the past for some users, and don't actually know how to do it. I didn't find any Wiki articles on gantry homing.

Jon

Jon, yes thats right. Its covered in the 2.8 homing sequence and is now amazingly simple with just 2 entries in the ini file.
X,Y,Z axes are now no longer mapped to the fixed joints of 0, 1 & 2
So X could be joint 9 now if you wanted it to be...
Coordinates below now has a 1: 1 relationship with joints 0,1,2,3.....,9

[KINS]
JOINTS = 4
KINEMATICS = trivkins coordinates=XXYZ

and the home_sequence for each joint that is part of an axis set is defined as a negative number

[JOINT_0]
HOME_SEQUENCE = -1
[JOINT_1]
HOME_SEQUENCE = -1

If you had two compound axes, you would use a different negative number for each axes

What I've found is that whilst this was set up and working in the core code, there were a number of error codes and the like mapped incorrectly in the various GUI's. (eg a X axis limit switch on joint 1 showed in the error as being on Axis Y) I found a few of these. I think that these have now been mostly fixed. The good news is that homing one side of a gantry is no longer permitted in joint mode!

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grijalvap
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01 Aug 2017 01:19 #96804 by grijalvap

Replied by grijalvap on topic A little surprised at the lack of activity.

Hi I'm another forum reader... you can get very good support and info on this forum.
However, you need to ask the correct question...

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