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Mill orientation
« on: May 01, 2011, 07:56:21 AM »
When looking at the machine view/table view window in Mach. it always wants to put the design at the bottom and to the left of the work area as shown. My mill is set up so that "home" is back and to the left. this is the way it was built. Is there a way to tell Mach this so that when looking at the table view it starts at the top left??

 (I am still weeding through the video tutorials)

Offline Hood

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Re: Mill orientation
« Reply #1 on: May 01, 2011, 08:11:29 AM »
Standard is like a graph, X0Y0 is lower left corner of the paper. If your home switches are at locations other than that position then you can enter a Home Off value in Homing and limits. The value you will enter is equal to the distance your axis is away from the standard machine zero point when you home.

You can of course set things up any way you like and feel comfortable with but it is best to stick with convention in my opinion as it wont cause issues down the road, setting up unconventionally may or may not cause problems but will certainly make things harder if moving to a machine that observes convention.

One last thing is remember that it is the tool position that dictates the XY and Z zeros and not the table movement. On a knee mill it is often confusing for a beginner as they see the table moving left when there is a positive X move and it looks wrong but if they think about the tool in relation to the work they will see it is right.

Oh another "one last thing"  ;D you dont have to have the home position as the point you start your work, you can jog wherever you like on the table and zero the axis, that sets up a work offset, the stanndard being the G54 but there are many more you can stor if you wish.
Hood
Re: Mill orientation
« Reply #2 on: May 01, 2011, 08:13:39 AM »
it doesn't matter where you home as you'll be machining from work offsets which you can set anywhere on the table. Your plus measurements should be from left to right on the x, from front to back on the y axis, and (for a column mill) from table to uppermost point on the z. These are tool movements.
It's worth having the home so that the tool goes back (table comes forward) on the y axis as you'll have more room to set the job up on the table.

Re: Mill orientation
« Reply #3 on: May 01, 2011, 08:18:48 AM »
My mill is a gantry type so the table is fixed. but i get what you are saying. and i have figured out how to do the work offset and get a program to run within the machines limits...so i am learning and getting it slowly figured out.

 I have the machine homed in. I move the machine to the point i want to start work at and zero the work offset. then regen the toolpath and it shows the work off the table in the view window. the program runs like this but i cant get the work to be shown ON the table...so i still have something not right.
Re: Mill orientation
« Reply #4 on: May 01, 2011, 08:21:04 AM »
I bet I have the Y axis set up wrong. it counts positive when moving forward.

Offline Hood

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Re: Mill orientation
« Reply #5 on: May 01, 2011, 08:22:37 AM »
It sounds like your code may have a start point in it other than the normal XYZ zero. for example your CAM may have chosen (or rather you within your CAM) an origin of some value which is way off your table.
Best to get that sorted in CAM but even then you can get around this by entering suitable values into the DROs to offset rather than just zeroing the DROs.
Hood
Re: Mill orientation
« Reply #6 on: May 01, 2011, 08:28:18 AM »
I am very much a beginner. I am no where near being able to use CAM's, or for that matter even know what that is!(I think i know) LOL!

 i am learning mach and just trying to get the machine to run the roadrunner test program that comes with mach hahaha!
Re: Mill orientation
« Reply #7 on: May 01, 2011, 08:31:17 AM »
Not knowing your bed size, when at home position, wouldn't your home DRO's settings then be something like X 0 Y 48.5 (Left, back corner of table)
Re: Mill orientation
« Reply #8 on: May 01, 2011, 08:38:49 AM »
hmm well. i have been able to home the table in...im pretty sure anyway and i have the table size figured out and entered in the home/limits section. so when its back and to the left and the machines home position the DRO's all are set to zero.

 When it moves forward it counts from zero to +19" and when it moves right it counts from 0 to +19" but it sounds like i need to set it up so that when it is at home. it is at 0-X and 19-Y and have it count down from +19 to 0 when moving forward.

 I have someone that lives in the MN area that is going to give me a hand at some point. I will keep tinkering with it and watch the rest of the videos in the meantime.

Offline Hood

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Re: Mill orientation
« Reply #9 on: May 01, 2011, 08:46:19 AM »
You need to set a Home Off value in Homing and Limits as mentioned above. That will mean when you home the Y axis will have for example 19 in the DRO and Mach will know machine zero is 19inch in the negative direction.

Ad to that it sounds like your Y axis is going the wrong way as the tool coming towards you should be a negative move, you can reverse the direction in Homing and Limits but you will also have to change the Home direction for that axis.
Hood