I am new to CNC'ing and I am almost   ready to make the first cut. I have read the tutorials about homing/referencing, but I am confused about positioning the tool to begin the cut. I will be using a 1/8" cutter to route a profile in 1/8" thick material (cut out) and drill holes thru the material. The material will rest on a 3/4" MDF backer board. I have put my drawing in LazyCam and created the code. It's not a complicated part, it's a chassis for an RC car. There are no arcs, mostly right angle, angle and straight cuts.

1. Does it matter how the bit is positioned in the router i.e. how much of the cutter is sticking out for want of a better word
2. Do you allow for the backer board and the thickness of the material, if so where and how
3. After homing do you jog the tool to the starting point and then do a REF/ALL command on the screen
4. I am just not clear on how the tool knows where to start the cut, and how to define that. It will affect the depth of the cut I set in LazyCam

I do not have access to my Gcode right now I will post later if needed.



Thanks for all your help,

John

John,

Have you tried watching the tutorials for LazyCam? That's a good start but I'm pretty sure you'll have questions afterwards anyway but you may understand it a bit more - 

Also, there's a LazyCam video that looks different than what you have because it had been updated since then but the rules basically still apply.

Dave

Usually you just do a RefAll once when you start Mach, the only other time you would have to do it is if for some reason you lose steps or press the Stop button (or E-Stop) while the machine is in motion. You can press the Stop after you have done a feedhold or the machine is not moving without the risk of losing position .
 Once you have done a Ref All then that lets Mach know where the machine coords of your machine is.
You can then Jog X Y and Z to where you want to start cutting and then press the zero button for each axis and that will make a work offset zero, you can confirm this buy pressing your Machine CoOrds button once and you will see that the distance in them is the distance you have just moved each axis, press it again and you will see that the work offset is zero. Normal practice for Z zero position is the surface of your work piece, X and Y may be a corner or the centre of the part but will be where you have told LazyCAM it is.

Hope you understand as I am not the best at explaining.

Hood

Yeah .........  right !
You do pretty good Hood......for a fellow that can't read.
EXCELLENT actuall...(as always)
RC

Sorry RC, the dogs just popped out for a few mins but when he gets back I will get him to read it out for me so that I can respond 
Hood

 
 
RC

OK thanks, I'll look at the LazyCam videos tutorials again and then apply what Hood said. 


John