Hi all, i have been busy the last couple of weeks with this project, it is a
turbo impeller, well i was trying to think of what would demonstrate what my imodela could do and first i thought i would finish doing my v8 engine block project that i started a couple of years ago but i still had a couple of hurdles to get around on that one, and while talking with a mate of mine i decided on the turbo impeller because over the years while visiting the engineering/machine shows we use to see that the turbo impeller was touted on many of the stalls so much so that we use to joke that any cnc machine had not made it until it could demonstrate that they could cut out a turbo impeller using their 5 axis capabilities

. So i put my mind to doing the same, the result of which follows.
All the cutting paths were done using only 3 axis paths as found in all cam software, including rolands. The design was turned in the software and the material was then turned on my flip / 4th axis table manually after each path was completed, my 4th axis table having 72 positions available. It all comes down to one hell of a lot paths to make and that is why it has taken me 2 weeks to complete it. I will say though i would not do it the same again next time around.
I think you may know that some years ago when J. F. Kennedy said
".... not because they are easy, but because they are hard" well that`s the reasoning i had.
Over the time it took to do this i have had the odd malfunction

as one of which you may of read in another of my posts concerning software, a couple of which was my own fault, after all it was difficult to go this length of time non stop without making a sing mistake

. I have learned quite a bit about what is required on the whole procedure and so i now feel i have gained quite a lot myself, although i don`t think i want to make another impeller.
The material is acrylic although this is not my favourite material as it is too brittle for the things i like to make, i prefer polycarbonate because it is more forgiving but i could not get a block thick enough. The acrylic is nicer to cut though, it has a finer `flake` when cut so less likely to clog cutters.
The cutters i used were 3mm 2flute carbide end mills which i sharpened to have a `fish tail`, i had sharpened this 2 times while doing this project.
I also used a `D` bit i ground from carbide this had a round end and 3mm Dia. , this i used for finishing and corners, this i reground 3 times during the time.
The roughing cuts were full 3mm dia and 0.3mm deep where needed after which i made passes of 0.2mm deep and 2mm wide cuts, the finishing with the `D` bit was 0.1mm wide and deep to get a good finish.
The actual time the imodela was in motion i guess was between 50 to 60 hrs and the rest of the time was doing the software and figuring out how to do things, i had to re go over some areas twice which was annoying.
So there we are then. I have made a short video, not the best quality but i`m a bit burnt out with the whole thing now so just hope you like it all the same.
youtube video http://youtu.be/gsBXnLLneaQ