A Familiar Ring

Trial Bell

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 large to actually run on my Taig Micro Mill. The various holders and spindles and tooling all take up space that has to stay within the movement limits of my mill. Time to go back to the drawing board for a little redesign.

This was not totally unexpected as my first example was only a proof of concept that I could create a working design, which I did. Next I had to measure everything to make working sketches of what size I should design back on the CAD drawing. That is what I did.

I have run the second bell design (dry run) on my Taig mill and all is well. I have a simple bell (in picture) that I will definitely be able to carve on my Taig. It does sort of look like an Apollo space capsule without it’s heat shield.

Once the bell is carved I will cast it in either brass or bronze. How it sounds, if it sounds at all, is not important. I first have to prove to myself that I can actually design, then cast a bell shaped object. If that works, and I have no worry that it wont, then I can start to refine the bell making process.

One limitation that actually hit me with a bit of a surprise is how small my Taig CNC mill really is and how much it limits the size of my project. Though it is after all, a micro-mill and that point is clearly evident. That doesn’t mean I wont have one heck of a great time designing and making small bells.

I can have years of occasional work just staying within the size limitations of the Taig. For now it is only for my own fun and entertainment and making small bells for family and friends. If there ever is a demand for larger bells, only then will I consider up-sizing the process. Only if it pays me to do so. Ha!

So it has been a good start and I have a really cool project using all kinds of technical computer drawing tools and equally technical machine tools that run of automatically by computer control. Well it really isn’t all that automatic.

Then I get to throw in my next favorite process of doing lost wax casting. That’s a step out of the ordinary too. After it is all said and done, I have a totally unique product that I will be very satisfied that I made myself. That is what this is all about.

I can easily choose to make this a process to see how small I can actually make a detailed bell. I have some very tiny wax milling tools at my fingertips and a great running machine that can do the job.

Ahhh… so much to do and so little time. I am just loving it!

I haven’t even thought about all the possibilities of what kind of decoration can be added above the bell. A whole ‘nother country to explore…