Hello Guest it is August 04, 2020, 09:48:50 AM

Author Topic: Setup advice needed for Newbie  (Read 2203 times)

0 Members and 1 Guest are viewing this topic.

Setup advice needed for Newbie
« on: November 06, 2014, 08:28:40 AM »
Question 1) Using Mach3 on a lathe. Working in inches and absolute mode.  Have spindle axis setup as Zed and negative toward spindle on left facing lathe from front and positive to right, toolpost in front. My questions are, if X-axis is positive away from me standing facing the lathe with spindle to the left, shouldn't the DRO for X increase toward the positive when I move the cross slide away from me. It currently goes negative. I have 4 home limit switches on the lathe. One at each end of the Zed axis and one at each end of the X axis. I set machine zero by setting home on the Zed axis to the right most positive direction switch and the x axis toward me the supposedly most negative direction switch. Is this correct? Is the DRO supposed to go negative as the x axis is moved in the positive direction?

Question 2) When zeroing a part in the lathe do you place cursor on Progdata so LED is on, touch part on outside edge of part to be turned and then click on ZERO axis for X and Zed? When I try to run a Wizard program for simple turning that way  when the program starts it pulls away from the part but continues to move back and forth and feed in and out  in air in front of the part it should be turning. I am in diameter mode, and set the start X at +1 for a 1" diameter stock and end at 0.75 if I want to take  0.25 off. Z is set at 0 to start and -0.5 to end. The Z axis seems to work fine the x axis works as above. Are there any manuals describing the Wizards?

Question 3) Is Part Zeroing for parting off the workpiece, is it set by move to the point of where you want to part off the workpiece and then zeroing each?

Question 3) How do I correct for backlash, what number(s) is placed in the backlash compensation screen and how do I determine them?

Sorry for all the questions I think Mach3 is great I just need to understand it better?

Thanks,
Dave

Offline rcaffin

*
  •  1,029 1,029
    • View Profile
Re: Setup advice needed for Newbie
« Reply #1 on: November 07, 2014, 03:33:51 AM »
Quote
if X-axis is positive away from me standing facing the lathe with spindle to the left
It would be VERY rare for that to apply. I am not aware of any cases. Normally, X is POSITIVE coming towards you from the Z axis.

Quote
When zeroing a part in the lathe do you place cursor on Progdata so LED is on
Sorry, but this makes no sense to me at all.

Quote
Is Part Zeroing for parting off the workpiece, is it set by move to the point of where you want to part off the workpiece and then zeroing each?
I am not sure I understand the question, but I think the answer is 'no'.

Quote
How do I correct for backlash, what number(s) is placed in the backlash compensation screen and how do I determine them?
Um. You need to be abls to measure the backlash first. I suspect that might have to wait a bit while you get some experience with your system.

Cheers
Roger
Setup advice needed for Newbie
« Reply #2 on: November 07, 2014, 02:43:36 PM »
Normally you set the tool lh edge on the face of the work and zero the z dro.  Set the tool on the periphery of the work and set the x dro to the diameter of the work (assuming you are working in diameter mode).  This also assumes that the end of the work is faced off and the work is cylindrical and coaxial with the spindle.  Unless you have ballscrews on your lathe don't try backlash compensation, in my experience it doesn't work for the levels of backlash you get on normal lathe feed screws, and anyway with a lathe you tend always to be cutting in the same direction.

And yes, z is negative towards the headstock, x is nominally zero when the tool is on the spindle axis and increases positive as the tool moves towards you.


Sent from my iPad using Tapatalk
Setup advice needed for Newbie
« Reply #3 on: November 07, 2014, 02:46:58 PM »
And yes, z is negative towards the headstock, x is nominally zero when the tool is on the spindle axis and increases positive as the tool moves towards you.


Sent from my iPad using Tapatalk
Re: Setup advice needed for Newbie
« Reply #4 on: November 07, 2014, 04:47:18 PM »
Thanks John that helps clear that up.

Offline rcaffin

*
  •  1,029 1,029
    • View Profile
Re: Setup advice needed for Newbie
« Reply #5 on: November 07, 2014, 04:55:58 PM »
Quote
Normally you set the tool lh edge on the face of the work and zero the z dro.
OR set the Z axis zero where you want it, with the tool in a suitable X position, and then butt the end of the material up against the tool. It can be a WHOLE LOT faster in a production environment to do it this way.

Um - I had better add that while this works fine with a chuck, it does not work with a collet, which pulls back.

Cheers
Roger

Setup advice needed for Newbie
« Reply #6 on: November 08, 2014, 05:38:10 PM »
Roger, I never thought of that, what a good idea!  Thanks.


Sent from my iPad using Tapatalk