Originally Posted by
PaulRowntree
Ok, I get the pocketing. I was thinking that roughing could be done just by replicating the chosen XY vector a few times, and then progressively flattening them keeping the same reference position for the Y=0 of the material. The attached CorelDraw image shows the effect, with the bottom curve being the final desired shape. Run each as an XZ profile (mind the order!) for a progressive approach to the final shape.
Cheers!
Paul, there is a natural progression in my thought process and experimenting, that is becoming very like this image.
I tried the pocketing, and it's downfall is speed. The feed rate is the same (slow) on the non cutting part of the pocket toolpath, as on the cutting part.
so then I duplicated my outline with an offset equivalent to my pass depth of cut, and enough copies to get to the final size. the downfall of this way, is the work piece needs to have material clearance as the cutter gets closer to the finished outline , as you would manually, and as your drawing shows Basically, there needs to be clearance for the cutter, and the cutting forces are different depending on the amount of cutter edge being used , i.e. not just the point of the cutter. If you can see what I am trying to say ?
It's all the stuff that comes automatically when you are cutting manually, but the CNC will only do what it's told ! so you virtually have to make the part in your head, and then translate that into a toolpath.
if that doesn't make sense ... it's because I'm VERY tired !
Rich
My 1st Build (ongoing) http://www.cnczone.com/forums/diy-cnc_router_table_machines/134670-one_big_one_smaller_my.html