|
| |
We had originally planned to ship a hot tub in the same time frame as our
A-Frame Cabin kit, but that didn't happen.
I severely underestimated how long it would take to acquire the software and
skills necessary to create the master.
January 10, 2005
by John Socha-Leialoha, Designer
I got started in this whole kit creation when a friend of mine and I learned
about desk-top CNC milling machines. The idea is that you use your computer to
create a model of a part, then have the milling machine make the part out of
brass or some other material.
Well, that sounded a lot simpler than it turned out to be. Once I got the
milling machine, I discovered I needed a good 3D modeling program. It took me
nearly a year to find one I liked. And then the real fun began--learning how to
use this program.
Instead of starting with something simple, I decided to create a nice hot tub
to go along with our A-Frame Cabin kit as
well as other houses like our Bungalow.
 |
As I mentioned above, the first step is to create the
3-D model in the computer. This took more time than I'd like to admit,
but that's mostly because I'm still learning how to use this very
complex program. And of course I'm trying to create something with very
complex curves as my first model, which probably wasn't the best place
to start. |
 |
The next step is to calculate tool paths. These
are the movements of the cutting tool. The tool paths shown here are for
an initial roughing pass using a 1/8" diameter cutter for an N scale
version of the hot tub. Basically, these paths cut the shape one layer
at a time. |
 |
Here you can see the actual part after the first pass
with the 1/8" diameter cutter. The material is a very high density foam
called tooling board, which is designed for making this type of master.
Inside the hot tub you can see the layers cut by the roughing pass. |
 |
The master is finished, and the next step is to make a
mold from this master. Going from the previous picture to this picture
required three more passes with progressively finer cutters. The master
shown here is larger than life, as the actual master is less than 1/4"
high (it's about .2" high). |
February 16, 2005
We've been busy working on some other projects that we're not quite ready to
show, which kept us away from the hot tub for a little while. But as you can see
below, we're getting very close to being finished with this project.
 |
The mold turned out very well, as you can see from this
casting. I painted the casting a metallic blue, then added a laser-cut
wood exterior. You can see we're almost ready to go into production! The
kit will require painting and adding the laser-cut wood skirt. Of
course, if you want figures in the hot tub, you'll probably want to
simulate some water. |
March 10, 2005
I wasn't happy with the level of detail on the original hot tub. It was OK in
N scale, but in the larger scales there just wasn't enough detail. So I threw
out the design and started over from scratch.
 |
This is the final design on the computer. Compare this
to the previous version of the design and you'll see there is a lot more
detail in this version of the model. Once I had a computer model with
enough detail, it was a fairly simple process to mill masters on the
milling machine. |
 |
I created a mold from a test master to see how it would
turn out. You can see the pre-production example I cast in this photo.
The paint job was from a spray can and was less than perfect. The
production version will come pre-painted by professionals in a lighter
blue, and wrapped with natural wood, as shown here. The masters for
the N, HO, and S scale hot tubs are now at the production house, so we
should have product ready to ship soon. The O scale master will follow
soon. |
|
