Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: D CUSTOMS on June 11, 2008, 02:44:53 PM

Title: Question on homeing
Post by: D CUSTOMS on June 11, 2008, 02:44:53 PM
Is this the correct homing.All these examples are based off standing in front of the machine.X all the way to the right and when moving left will build in the positive number.Y all the way out towards me.When moving towards the machine numbers will build in the positive.Z all the way up.As the knee  drops numbers will build in the??
Title: Re: Question on homeing
Post by: Chip on June 11, 2008, 04:02:40 PM
Hi, D CUSTOMS

The spindle should be moving, - X left, - Y towards you & +Z up for Home Position.

Chip
Title: Re: Question on homeing
Post by: D CUSTOMS on June 11, 2008, 04:10:44 PM
Thanks for the responce its tough being a beginner
Title: Re: Question on homeing
Post by: Hood on June 11, 2008, 04:23:34 PM
Not really sure what you are asking here, are you asking where it is best to set the home position or are you asking which direction is a positive move?
 If the former then its just a matter of where you want to put your home switches.
 If the latter then its a different story. No matter what type of machine you have you have to think of the tool in relation to the work to see which is the positive direction for each axis. On a mill the lower left of the workpiece is your x and y zero and the top is the  z zero, if you move the tool to the right (table left)  it is moving positive, for the Y it is the tool away from you (table towards you) and for the Z  tool down into the work (Quill down or knee up) is a negative move.

 This then follows that the easiest place to set up your home switches is when the tool is lower left corner of your table and furthest away on the Z. That would relate to your table fully right and fully away from you with your knee fully down (or quill up).
 As said before you can set the homing switches at any position but if you dont have them as above then you will need to enter home off dimensions into your homing and limits page so that Mach knows the zero position of each axis.

Let me know if this answers your question and if you have any doubts just post again and I will try and explain further.

Hood
Title: Re: Question on homeing
Post by: D CUSTOMS on June 11, 2008, 06:03:34 PM
Hood,
 
X moving to the right is negative and moving left is positive.
Y moving table to me is negative and moving away is positive.
Z knee going down is positive and up is negative.
Is this correct??What do i do if the dro on mach registers a movement opposite of what it should be?       
Title: Re: Question on homeing
Post by: Hood on June 11, 2008, 06:41:21 PM
If you are talking table movement for the X then it is correct.
Y is not correct, table should movetowards you for the positive direction.
Z is correct, knee down is increasing the gap between work and tool so it is a positive movement.
To reverse an axis go to homing and limits and choose the reversed option. You could also change the active state of the direction pin for an axis but some drives seemingly are particular of the state so it might not be the best way.

Hood
Title: Re: Question on homeing
Post by: D CUSTOMS on June 11, 2008, 06:56:07 PM
Hood thank you for clearing that up for me
Title: Re: Question on homeing
Post by: Hood on June 11, 2008, 07:12:10 PM
Just wait until you get a lathe and the fun will start again LOL My Lathe has rear turret and front tool post. If I am using the rear turret  then X positive is the slide moving away from me but if I am using the front post that is a negative direction :D Thats why its better to think in terms of tool and work instead of axis direction.
Hood
Title: Re: Question on homeing
Post by: jimpinder on June 12, 2008, 04:20:09 AM
No wonder the Scots invented golf (and Scotch) :D
Title: Re: Question on homeing
Post by: Hood on June 12, 2008, 05:16:15 AM
:D
Title: Re: Question on homeing
Post by: Chaoticone on June 12, 2008, 08:54:55 PM
 ;D

Brett