Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: amarillis on May 07, 2010, 09:36:26 AM

Title: Mach3 Turn and CNC setup
Post by: amarillis on May 07, 2010, 09:36:26 AM
Hi. This is my first post, so if this topic has been already discussed somewhere else please insert the topic link.

OK. The problem is that after upgrading my Proxxon PD400 to CNC and after I've used Mach3turn to set everything like backlash, motor tuning and so on, I changed the X coordinate system from radius to diameter, because my DRO works with diameters units.
Everything in the setup and motor tunning has changed. The backlash does not work anymore and I've to recalculate it again, the step per unit has doubled the value, and so on.
Is there anybody out there that can tell me where did I go wrong and what is the correct procedure to calibrate the system?
Why if I change the coordinate system from radius to diameter everything stops working?
Thanks in advance for the answers.

Alberto
Title: Re: Mach3 Turn and CNC setup
Post by: RICH on May 07, 2010, 04:36:19 PM
Alberto,
I change between radius and diameter a lot on the lathe and have never seen what your saying happened.
Did you save the configuration?
What version of Mach are you using?
Are you using a custom screen set for your lathe?
What units are you working in?

RICH
Title: Re: Mach3 Turn and CNC setup
Post by: amarillis on May 08, 2010, 03:42:15 PM
I always save the configuration.
The version is 1.84.....
No I do not use any custom screen.
I work in mm.

When I use Mach3 Mill there's an usefull Calibrate screen that I think everybody know.
Is there anything like this for the Lathe version?

It is still not clear to me in which mode (radius or diameter) you calibrate your system. I mean the very first time you start up the program you try to move the motor and verify if the travel of each axis match the reading on the external measurement system (in my case a Sino DRO). What is the correct procedure to calibrate each axis?

Now I'm in the diameter mode, and since my DRO also measure diameter I don't think I will change. Everything works fine. But if I try to change to radius the X axis is no more calibrated. For example the backlash is doubled, and also the step per units is no more correct.

Thanks for the answers.
Alberto
Title: Re: Mach3 Turn and CNC setup
Post by: RICH on May 08, 2010, 05:04:31 PM
I would suggest you update to a later version of Mach.

Quote
Is there anything like this for the Lathe version?
Not available in the lathe screen , but you can use the mill screen and then use those numbers in the lathe screen motor tuning.
( while in Mach 3 Turn , just change the screen set to the mill set and then go back to the lathe set. )

Quote
What is the correct procedure to calibrate each axis?
I use an indicator to compare commanded movement to actual movement. You should also check for backlash.
Have a look at the manual.

Remember, when in Mach3 Turn and machine coordinates, the DRO will show the absolute X distance in terms of radius, even though you are in diameter mode.

RICH


Title: Re: Mach3 Turn and CNC setup
Post by: amarillis on May 09, 2010, 02:29:02 AM
Thanks again Rich.
The 1.84 is a really stable and tested version and this is why I'd prefer not to upgrade....
I'll try to swap from the Lathe and the Mill screen set to use the Calibration function. That's really a good hint....
Yes I checked for backlash and considered it in my computing.

Not still clear the problem with the coordinates system. No answer to my questions, but the upgrade?

Alberto
Title: Re: Mach3 Turn and CNC setup
Post by: RICH on May 09, 2010, 08:30:04 AM
Quote
Not still clear the problem with the coordinates system. No answer to my questions, but the upgrade?
- Never used v1.84, and there have been a number of upgrades sine then.

- In Mill there is no radius / diameter selection as in Turn, so when you use the calibration it makes no difference. The Mill should be in metric  units also and make sure that your axes are not scaled.
So just do a move of say 10 mm and when the moved distance is correct as compared to the commanded distance accept the steps per unit and they will be
saved to current profile. So if your digital the readout is diameter then it should agree with Mach.

When you go back to using the lathe set you will see that the steps per unit were changed. Your configuration  in ports and pins >lathe options should be diameter.
Make sure you have selected Program or Part coordinates in the manual screen of Turn. If you have selected Machine coordinated the dipslayed DRO value will be
1/2 the commanded as machine coord displays in terms of absolute and radius.

I am thinking that is where you are getting confused, but, like i said i never used that old version and can't say what is does.

RICH
Title: Re: Mach3 Turn and CNC setup
Post by: amarillis on May 09, 2010, 02:51:55 PM
Thanks again Rich.
Today I did the calibartion for the axis system and everything was OK. I just have to switch from diameter to radius on my DRO before calibrating the X axis.
Then got back to the diameter when using the lathe.

I'll try the sw upgrade as soon as possible. What's the last reliable version for both turn and mill?
Thank for your contribute.

Alberto
Title: Re: Mach3 Turn and CNC setup
Post by: Hood on May 09, 2010, 05:20:48 PM
I have never used Backlash comp either in Mill or Lathe so cant say anything about that.
As for calibration, really that should just be a calculation of steps per unit and it should not matter whether you do it in Rad or Dia mode. I set up my lathe in Dia mode and just entered the steps per unit (mm) and that was it, I have done tests in Rad mode and it has been equally accurate as it should be but again I have never used comp so cant speak how turn reacts to a change when using it.
Hood
Title: Re: Mach3 Turn and CNC setup
Post by: amarillis on May 10, 2010, 04:15:47 AM
So, what Mach3 version are you using?
Is not only a matter of backlash of course.
I mainly address the problem with the motor tuning procedure.
Anyway, maybe this is due to my old version, I don't know....
Title: Re: Mach3 Turn and CNC setup
Post by: Hood on May 10, 2010, 04:57:31 AM
I am using 3.042.021 at the moment but it would have been an earlier version but definitely not as old as 1.84, thats probably about 4 yrs old LOL

Hood