Ok, so I recently build a Greenbull CNC from Buildyourcnc.com.  So far I haven't ran into any issues I wasn't able to solve via Youtube or Google.  Today, I thought I was at a point where I could cut out a stupid chicken I purchased from makecnc.com.  Well, All I had for material was a 4 x 8 piece of mdf.  I ran the DFX through Aspire and set it all up to run and exported the Gcode.  Great, looks like I'm about to have a big mdf chicken.  Now I'm in Mach3 and I load the Gcode.  Problems start here:

1:  For some reason mach3 seems to think my y axis is the longest part of my table.  It orientates the project so as to run the length of the project on the width of the table. 

2:  I never know exactly where the machine is going to start cutting.  I set it where I expect it to start, zero all of the axis and hit go.  It hauls ass across the table and starts where ever it seems to want.

That is all for now.    Any ideas?

Mach3 doesn't think anything, it does what you tell it, your G-code defines the X and Y moves so you need to

change your machine definition in CAM
or
rotate the part 90 degrees in your CAD package
or
swap your axes in Mach3

If you define your zero in CAD/CAM you will know where to set it on your machine, if you're allowing the software to define a default zero you need to note where it is on the stock, you can then set Mach3's zero appropriately,

Regards,
Nick

1) In Mach3, the X axis is always left to right. You CAN NOT change this. It should look exactly the same way in Mach3 as it does in Aspire.

2) You set your 0,0 position in Aspire, as one of the 4 corners of the workpiece, or the center. Zero the X and Y axis in Mach3 in the appropriate place, and it should be cutting exactly where you want it to.
Be aware that if you may need to move the imported vectors after importing them, as they may import to a different location then you want.

Thanks for the info.  I'll do a little testing with that in mind.