hexapod configuration, oh my!

Gentlemen,

I am wrapping up the mechanical integration of a hexapod that I am building and starting in on the software side. I am using a beagleboneblack running machinekit and linuxcnc. I am new to linux and am in over my head but have managed to boot up the hexapod module of linuxcnc on the BBB.

I believe my next move is to configure the hexapod module of linuxcnc so that it knows the machine geometry. To do this, I know that I need to edit hexapod.hal and genhehkins.h but I don't know how to actually do that. Where is the file located? How do I know which parameters to edit? How do I recompile afterwards? Where would be a good place to learn about all of this? I have setup 3 axis mach3 mill, but this is my first experience with linux and linuxCNC.

Another question; I have used the term hexapod to describe my machine but I am not completely sure that it is technically a hexapod. pkmcnc's hexapod uses ball screw arms that change in length. My machine is setup like a delta (fixed arm length, arm's upper fixture point moves on a linear slide):
www.3ders.org/articles/20120714-rostock-...inter-prototype.html
So that brings up the question, can I even configure the hexapod module for my machine?

Thanks,
Adam

I'm diving in head first, starting with this page
wiki.linuxcnc.org/cgi-bin/wiki.pl?LinuxCNCKnowledgeBase
It sounds like anything is possible in LCNC, but the kinematics need to written first.

firstly welcome to Linuxcnc ,
their are a number of areas you have covered so i'll try and tackle them , in some sort of order , the kins used is Lineardeltakins and is all ready installed in the machinekit image

so changing the kins shown at the top of the hal file will change this for you

the configuration files on the beaglebone are held in a directory called linuxcnc in your home folder , follow the tree till you come to configs/Beaglebone/ < your hardware > BeBoPr , capes etc

Just to give you inspriation here's deltakins on a beaglebone


see how you get on , and ask away .

their is also the beaglebone specific blog at blog.machinekit.io/

Thank you for the warm welcome!

I should have been more clear when describing my machine. It is a 6 axis, 6 DOF machine. It is like PKMCNC's machine in that the head can translate in X,Y,Z and rotate in A,B,C:
www.youtube.com/user/PKM077

My machine is different from PKMCNC's hexapod in that his hexapod uses arms that change in length via linear actuators, while my machine uses arms of constant length, moving the upper ball joint, like the linear delta you have linked to.

Great blog you have linked to. I have thought about contacting Charles Steinkuehler.

without knowing what cape or interface your using , it's difficult to be specific , however i do have Brandons deltakins configs , either way it should not be too difficult to
modify the kins if we have to , ( they are also on Charles github ) , the other kins file used with the videos of 6dof i believe to be genhexkins , unless someone puts me right .

send me some information off list if you wish , to save clogging up the forum .

I am not using a cape. I am using a bare BBB with jumpers to a breadboard. DRV8825 stepper motor drivers are mounted to breadboard.

What information would you like me to send you?

arh yes the good old stepsticks ! , you should not have any problem driving them from the default configs.

so look at the genhexkins again it's part of machinekit , so you should just need to change the line at the top of your config file to load genhexkins instead of the default