4th Axis

Postby kenlambert on 01 Dec 2008 20:05
How do I get my 4th axis ( rotory table ) setup and running on my Taig , I am useing mach 3 and Bob Cad, maby some kind of test code or something would help thanks Kenneth


Re: 4th Axis

Postby jeffD on 04 Dec 2008 21:21
I run a 4th axis with both CncPro and TurboCnc. No specific help for Mach3 but I can describe the logic I use.

Normally I use the circumference of the part to determine the steps per mm as a linear axis. Working circumference can be inside the stock and usually is. Every job gets a different number.

With TurboCnc there is some mod weirdness when using an angular mode so I just set it up as linear based on a 360 length.

No clue about BobCad, 99% of my rotary work is modeled as flat and the miss-guided controller and hardware make it round. Bang your head against the wall often enough and it starts to make sense but it is not easy in the beginning.

< www gmavt.net/~jdemand > for some of my learning experiences.

Jeff


Re: 4th Axis

Postby awerby on 05 Dec 2008 21:11
There are some things you need to do in order to get the 4th axis to run swiftly in Mach. For one thing, you should enter a number like .001 in the box for the A axis diameter. You have to tell it that the 4th axis is rotary, and to "use diameter for feedrate". Once you've done that, you'll need to experiment a bit to make sure it doesn't go too fast and stall out, especially on moves that combine moves in the A axis with moves in Z. If it does stall, you probably need to reduce your velocity and accelleration in A, and make sure that your steps per unit are correct (remembering that the units for these moves are degrees, not mm or inches).

Andrew Werby
www.computersculpture.com

So just what are people using for their 4th axis and how did you connect it to your controller, what are the advantages/disadvantages of the method you chose? Would you recommend it to others, here is your chance to praise or vent.

Bryan

I know I have a place on my controller box for a A axis and all I have is a stepper motor hooked up to it right now (use it for testing Mach 3 is all).

I have a old Deep Groove Controller, and running Cut 2D/Cut 3D/ Photo-carve to generate G code and Mach 3 to interpret the G code for my Taig Mill. ( I tend to draw In Autocad).

Well, I don't really know much about it but I know enough to be dangerous.

It really dpends on how YOU want to set it up and I couldn't explain it any better than this post here on the Mach 3 forum.

By the way, are you "bfairey" over there?:

http://www.machsupport.com/forum/index.php/topic,5281.0.html

Dave

definately not bfairey (NOT) no I will be Bryan Or Bryan M, or if I use a handle it is usually The_mariner