Author Topic: table display and what i cut is backwards  (Read 2872 times)

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Offline needmoretools

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table display and what i cut is backwards
« on: August 06, 2013, 09:22:24 PM »
I used the trial version of cut 2d.  I cut the Rocket name plate out but it was reversed on the wood.  Also the Table display is reversed.  This was my first cut and even tho it looks great it is still backwards.  can anyone help me.  also i have set up my limits and homing and all that works fine.  when i reference everything goes to the home position.  I did however do a dry rum before i cat with the z axis up high and noticed the z axis was running backwards so i just reversed it in motor outputs.  maybe thats not right but i have been on this project for over a year and wanted to see something work..
« Last Edit: August 06, 2013, 09:28:10 PM by needmoretools »

Offline Hood

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Re: table display and what i cut is backwards
« Reply #1 on: August 07, 2013, 04:05:08 AM »
Can you post a screenshot of what you are seeing.
Hood

Offline needmoretools

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Re: table display and what i cut is backwards
« Reply #2 on: August 07, 2013, 06:36:03 PM »
Hello Hood,  Thanks for answering.  Ok i have attached three pics.  The one with Mach3 in table display shows the work in the bottom left corner and it should be in the upper left corner.  The Image show to be correct when not in table display.  But as you can see in pic of what i cut its like a mirror image.  Any other info that you may need please ask and i thank you for your help.  Hope i can return the favor one day.

Offline Hood

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Re: table display and what i cut is backwards
« Reply #3 on: August 07, 2013, 06:41:44 PM »
Ok first thing is you seem to be homing to top right, if that is the case then you would be better setting a home off value for X and Y equal to  the travel of each axis. That will mean when you home the machine coords will be set to zero at lower right and your home position will be set as max travel of X and Y. You do that from Config then Homing and Limits.

Also would seem you have your X axis the wrong way, you will need to either change the active state of the Dir pin for the X in ports and Pins, Motor Outputs or it can also be reversed in Homing and Limits. You will likely also have to change the Home Negative setting in Homing and Limits for the X axis.

Hood

Offline needmoretools

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Re: table display and what i cut is backwards
« Reply #4 on: August 08, 2013, 06:14:42 PM »
Hello Hood,  Ok changed the wrong way X Axis and now engraving the correct way.  Now either im not understanding what you mean with setting home off at full length of table or doing it wrong.  Looking at mach3 video on homing and limits it shows red lines representing the table and i dont have that in table display.  I get a dash white line.  I tried changing the home off for x and y doing both at the same time and then just each and thats not working.  I know im not telling you all you need to know so please ask cause i dont know what you need to know.  Thanks for your help.

Offline Hood

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Re: table display and what i cut is backwards
« Reply #5 on: August 08, 2013, 06:57:15 PM »
Ok there are two coordinate systems in Mach, in fact in any CNC. You have Machine Coordinates and Work Offset Coordinates.
Machine coords are mainly for Mach so that it can keep track of where it is, the user mainly needs the work offsets.
The Machine coords are set by homing. When you home the machine it will move to the switches and back off and then set the machine coords zero where your home switches are. Now normal convention dictates that machine zero is X fully negative, Y fully negative and Z fully positive, thus all X and Y moves in machine coords are positive and Z negative.
This only works if your machine homes fully negative X and Y and positive Z.
It sounds to me like you are homing so that when at home position the tool is fully positive on X and Y. This is not really an issue but can be problematic if you wish to reference machine coords and dont really have a good idea what or where they are, it is much easier to envisage machine zero as being lower left (think of a graph on paper, X and Y zero is lower left).
So to get around that what you do is set a home off value equal to the distance the axis in question is away from being fully negative. Doing that will mean when you home your machine the machine coords will not read zero but instead will read the distance (in a positive value for X and Y and negative for z) that your machine is away from machine zero. Thus if you commanded a G53 G0 X0 YO the machine would move fully negative.

Doing that will allow you to set Soft limits for X and Y min and Z Max as zero and set X and Y Max and Z Min as the distance of each axis (Z will of course be a negative number)

Now Work offset coords, they are the ones the user usually watches and deals with, they can start anywhere you like on your table, for example you may wish to have work offset zero as the middle of your travels, so you would jog to the position you wish zero to be then press the zero at the side of each DRO and you have now just set up a work offset. If you regenerate the toolpath you will see your work is now where you want it.

Now the Table view in Mach, it has changed a bit from the time the videos were done, the white dotted line is the way it is now also when you change between table and work views you need to press Regen after to see the proper view.

So to summarise, you can keep the machine coords the way you have them now if you wish or you could change them as detailed (Home Off value) to follow convention, its up to you on that one :)

Hood