Quarter Plate holder and ground glass design are done. Attached is the design of the holder with dark slide and door.
Once you have a design you need to break it apart for the mill. It can’t understand the files directly and for standard milling it can’t understand 3D either. Now there are ways to make 3D, but for designs like this we don’t need 3D, just what’s called 2.5D which allows me to select lines of the design and tell the program how deep to cut each line.
On the bottom of the photo you’ll see each part flattened (except for the light trap on the top right, I still need to flatten that). We want to keep the 3D model in the same document because as we bring these flattened pieces into our CAM software we’re going to want to refer to the original model for depths. At this point I still need to cut the pieces into strips – think a picture frame. Instead of buying costly wood that is thick enough to mill the frame pieces and then throw away the middle, why not put 45° corners on them and then glue and nail them together?
The size of these pieces depend on the width of the wood stock I have on hand, or sold locally. Thickness of the finished parts may vary as well. If I can adjust the part a little one way or the other while saving time that’s a bonus. Remember that for each cut I’m adding time on the mill table.
I can also re-use this for the ground glass. If I build another holder without the light trap/door and adjust for thickness I have a ground glass that will be perfectly on the same plane as my wet plate!