Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: chrispol on September 18, 2006, 08:17:58 PM

Title: A Axis Questions
Post by: chrispol on September 18, 2006, 08:17:58 PM
Ok here's the deal i'm running x,y,z at 2000 steps my A axis runs at 300 steps and i usually use a feed of 25, x y z are fine but man does my a crawle it's soo slow it hurst, is there a way to override frrd rates for an axis? i would like my a axis to have a feed of 2000

Just a question, any other ideas are welcome
Title: Re: A Axis Questions
Post by: allanjs on September 18, 2006, 10:39:15 PM
You should be able to set the steps under config motor tuning A axis.
Is this a rotary axis ? If yes it should be programmed in degrees per minute.
Does it crawl only when programmed with another axis move ? If yes
you should be using G93 mode at the time you move it with another axis.
Hope this helps some.
Title: Re: A Axis Questions
Post by: chrispol on September 18, 2006, 10:49:41 PM
yes it's rotary 300 steps set in mach 3 motor tuning and basically my a axis crawls slowwwwwww

i'm using bobo cad, i have a feeling it's sending out inch per min and not degrees per minuite how can i get around this??
Title: Re: A Axis Questions
Post by: allanjs on September 18, 2006, 11:02:55 PM
What happens if you just edit the code to a higher feed rate ?
Is it crawling only when moving the A axis only or what happens when moving
it with another axis ? You can change the steps in Mach3 easily. Possibly
you need to have it at some value higher.
Title: Re: A Axis Questions
Post by: chrispol on September 18, 2006, 11:09:11 PM
yeah if i edit the a moves by hand to lets say a feedrate of 2000 it zips along, not an ideal solution as some of these files have alot of lines :(
Title: Re: A Axis Questions
Post by: allanjs on September 18, 2006, 11:19:34 PM
I have programmed a lot of rotary axii in my time and unfortunatly that is the
way it works. We have to stop and think about this for a minute. The program is
just outputting a value/unit. exm. F10 is 10 inches per minute if inches is set as the units.
This could be 10mm per minute if mm is set as the units.
On a rotary at F10 it is again 10 units per minute but the units are degrees. Do you see
what I am getting at ?
If you are programming the rotary axis with BobCad can you change BobCads output when
it sees the A axis so as to increase the feed. Or if you want to another way is to program the
A axis in G93 mode. (inverse time) The default in BobCad I'm sure is G94. I personally dod not
like BobCad although it's been a few years since I used it. Actually I write all of my own code.
Title: Re: A Axis Questions
Post by: allanjs on September 18, 2006, 11:35:20 PM
A little more thought :
None of the CAM programs I ever used, MasterCam, SmartCam, GibsCam etc
have all of the answers for all of the real life situations that come up in machining.
That is why they all have built in editors. If you rely solely on a cam program you
will become very frustrated, believe me. As a person gains experiece with cnc machining,
cam programs, cad programs and even tooling you will ask yourself "Why didn't I do it like that?"
Learn the editor and use the search and (destroy) I mean replace option. It will become your
friend.


Title: Re: A Axis Questions
Post by: chad on September 18, 2006, 11:57:30 PM
Did you go into the settings screen and set your rotation diameter? I seem to remember someone else having this problem. Sorry i haven't built a rotary axis like that.

Chad
?
Title: Re: A Axis Questions
Post by: Brian Barker on September 19, 2006, 07:38:20 PM
Chad is spot on :) and you need to turn on Feedrate by rad on the toolpath config dialog