Guys, firstly again I have to say thanks very much for your help. It's an amazing world to be able to sit at a computer asking questions and have experts from all over the world chipping in voluntarily to help. Much appreciated.
I have uploaded the file that I've recently been working on. You can download it
HERE
I'd really appreciate any advice on how to best handle it. My strategy so far after much trial and error has been to:
1) create a top plane and select that for the facing
2) hide the plane and reselect the mould shape. Using a region curve around the 3D wing area, do a roughing, then a Z level at 60 degrees limit, then do a planar finish at 50 degrees limit.
3) I go to the layer for the trailing edge trench (created earlier and hidden in a separate layer) then select it as the model, select its top curve as the region, and do a Z level cut into it.
4) Then do each hole as a pocket with an undersized cutter (it has to be a particular diameter).
5) Then profile cut the outside of the mould.
I have numerous questions ... to be honest I wish I could hire someone to sit with me for a few hours and work through what I'm doing.
A couple of the obvious questions:
When creating a number of toolpaths (say facing, roughing, z level then planar) do subsequent toolpaths make their calculations based on the amount of material left from previous cuts? Or is each toolpath calculated independent of previous cuts? I am sure that they do look back at previous cuts because the Z level affects the planar finish. But that brings the question - if you recalculate an earlier path (eg if you change the cutter or stepdown for the roughing cut) do you then need to go through each of the subsequent planar toolpaths and tell them to recalculate?? Does it make any difference to this if the path layers are hidden, or locked? Is it essential that they are in the right order in the list for recalculation? Or ... if you want to edit an early cut in this way, is it better to go right back to square one and create each path new, rather than recalculating them? (whew, I'm gonna overload you guys!).
If I create a toolpath but then decide to change the cutter and then recalculate the path, it doesn't change the name of the layer and still has the old name, so I have trouble working out what cutter it is now set to (unless I postprocess it and look at the report). Is there an easy way to tell what cutter is currently selected for a path?
Similarly with regions - (I'm probably not smart enough to ask the question coherently ...) if you close the file and re-open it, you have to re-select the model before you can edit any toolpaths. Does it remember the region curve selections or do you have to re-select those every time you re-open the file?
The biggest issue I have with getting an optimal 3D finish toolpath for the attached model is this: I want to avoid the cutter from doing changes of direction right on the leading edge curve as it can make it a bit messy. Ideally, I'd like the cutter to run in parallel X cuts from trailing edge and up over the leading edge (LE), out into the air above and outside the LE, then re-enter cleanly for the next pass. I set the shape of the wing as a region curve and did the a planar finishing with parallel X, but the cutter did lots of little movements around the LE on each pass, wasting time and making some unwanted marks. I got around this by doing a Z level finishing cut at 60 degrees, then doing the planar finishing at 50 degrees. This resulted in it completely avoiding the LE area, but the path still jumps up to the outside of the region then back in again ... and at the end of the run it goes along trimming up and nibbling around the very corner of the leading edge, which I don't want. I found that I could prevent this by selecting both "stop at parting line" and "exclude flat surfaces" but then it didn't cut a small spot in the middle of the wing, where it was flat! I would really like to know how to get around this!
If I select the 4 circles and "drill" them using a smaller ball cutter and pocketing, it does one Z level traversing from hole to hole before moving down a Z level then running around all 4 holes again. Is there a way to select all 4 holes and have the machine do all the work on one hole before moving to the next? My workaround is to do each hole's toolpath separately.
Very sorry for the overwhelming amount of questions ...
Cheers
Andrew