Hi phellas, im new at this, i bought a cnc fireball v90 with probotix. I start making parts on solidworks with all mesures right, using meshcam v5 to create a mach3 file, yes i´m using mach3,
but when the part is finished all mesures are wrong, its like it been shrunken.
i really dont know what to do.
Can someone help? i will be really apreciated 

TAKASHI,
Make sure your steps per units and working  units  are correct and that you are not scaling in Mach3.

You may want to remark how much the measurements are off.
Do something simple to test your machine movements  before using more complex software so we can help with the problem.

RICH

RICH,
Thanks for reply, i will try do that, but the part i made its simple, its an Arm of rc tamiya, in solidworks it mesure 41.10mm X 37.30mm,
whem done, mesures 35.32mm x 33.97mm...
I will try and post here the results 

For something simple I was meaning something like a 50.8mm ( 2" )  square where a  trueing cut is made to surface and then another cut is done at some depth.
Then do a shallow profile cut to dimension. This is done with one of the simple wizards and eliminates something that you may be doing in Solid works
and MeshCAm.

RICH