Yes! It can be done, as if there was any doubt.
I started with a 2″ diameter 3″ long wax cylinder. On the Taig micro lathe I turned half the length down to just over 1″ (not critical) so it could be held in the self centering 4 jaw chuck shown here. Once in this chuck it was never removed until finished.
I machined the inside on the Taig CNC mill as a 3D pocket. Then I switched to the 4 axis setup and ran the outside profile. When finished is shown in the first picture. Note the smooth finish that is possible.
Then I went back to the lathe (still in the original chuck) and turned down the stem and top of the bell. It would have been too weak if I had done this earlier. The big end will be cut off before spruing for the cast.
Not bad for a first try but still a lot of things to tweak.
The next bell I will spend more time on the CNC picture taking. I’ll do some video of the machining action. There was quite a pile of wax chips and turning ribbons. That green wax is a joy to machine. The bottom three pictures shown are more fitting I suppose for the lost wax casting over in “Ramblin’ Dan’s Workshop” than here in the machine shop blog but to get to this point there was a whole heck of a lot of CNC machining and some manual lathe work.
This has been a very interesting and rewarding weekend for me. I have been involved in some creative effort refreshing long unused skills in 3D CAD drawing (Rhinoceros 5) and 4 axis RhinoCAM generation and then the operation of my 4 axis Taig CNC mill.
All this so I can get to work on my bell making project. What it has done is really perked me up for using the skills I have let set idle for a bit longer than I ever intended. After this long weekend I feel that I am back on track.
My plan is to design small bells in three dimensional computer assisted drafting (CAD). That is one set of skills, learning all the components of a very powerful drawing program. Rhino is one of the top rated software packages for 3D drawing and certainly worthy of high praise.
Once the drawing is made, the designer must then have the knowledge to visualize how it will be milled, in my case from a cylinder of wax. It is definitely NOT a push the button and out pops the tool path for the CNC mill, far from it. The cool part is the cutting can be simulated with graphics before ever taking it to the machine tool.
Once I have simulations that run good, I take the code out to the shop and actually run it on the CNC milling machine. It isn’t loaded for actual cutting but what I call a “dry run” just watching all the moves the machine makes. That is to make sure it will run well on the real machine and where I can see how much room I have on my small machines to make all the moves.
This is where I discovered my first design was too… Continue reading