Jim Hawkins 3D Vacuum Tube Art
Array of 250TH Tube model
|I modeled this 250TH in the early 1990s
using 3D Studio running on DOS. It was my
first modeling of a vacuum tube.
All cylindrical parts were created by drawing
a spline outline, then using the "Lathe" tool.
There was no raytracing or capability to add
refractive properties to the glass, so I tinted it.
The bumpy top globe was a result of my
Lack of experience with splines.
The tube I modeled it from is from an old radar
set a friend unloaded on me when I was a young
ham operator in my teens.
|I used the above model to create a
fly-through animation, which was
used by a public television show,
at their request, in the closing credits.
Prior to the closing, the host announced
the animation and named me
as the animator.
3D animation was still in its infancy at the time.
The show was called PCTV, which aired in New
The end credit specifies the computer I was
currently using in 2010. My present computer
is a big upgrade from that time. I was glad to get
rid of Vista!
|This is the same model, except the envelope was
completely rebuilt in 3DS MAX using a technique of
shaping a cylinder with a 2D background reference.
The glass has an index of refraction of 1.5. Another
improvement is the glass protrusion around the grid
connection on the side. When I modeled the original
version I had no idea how to reshape surfaces by
manipulating the actual mesh. These skills were
learned in numerous tutorials on YouTube.
New, more realistic materials and a new rendering
engine (Mental Ray) became available as
3DS MAX evolved.
Note the green tinted glass
where the connections
pass through the envelope.
The glass is "doped" with
Uranium to lower its
coefficient of expansion to
minimize the chances of breakage
of the seal when the tube is heated
My Geiger counter does detect the
additional radiation and these parts
fluoresce blue with an ultraviolet light.
|Another view with a simple gradient background.|
|View up into the anode
array with lit filaments.
Reflections visible on
the inside of the envelope.
|Wireframe only. For the benefit of modelers.
The inside glass shape at the bottom of the envelope for
wire connections was accomplished as follows:
1) Shape was inset, inset support edge, then extruded.
2) Used Swift Loop tool to define beginning of shaping portion.
3) Using Polgon select to select top of extrusion
4) Grow selection to boundary then shift-move piece down
out of envelope to make a clone.
5) Make another clone of the piece in case I screw up
6) Flip Normals so that I can model from the outside
7) Selecting points in such a fashion to indent so a "cross"
is left. This can be done many ways by adding edges, selecting
vertices and shrinking it.
8) Bulge the cross sides on the tops and sides for more realistic
9) When satisfied with shape, flip normals again so that inside is
now the outside.
10) Select the same polygons inside the envelope, delete them
then insert the reshaped support carefully and weld the piece back
to the shape.
|First model of the 5604. I purchased the tube
at a hamfest for $50. This was a quicky eyeball
model I had planned to use for a QSL, but never did.
|I remodeled the entire envelope, fins and band.
Used new materials for glass and chrome.
The 5604 was primarily used for inductive heating
First modeled in 2001
|RCA 860 Power Triode|
|Side view closeup of Anode
|Screen shot of 860 model before
smoothing and rendering.
Shows surface modeling topology.
|Plain view with greyscale backtround.|
|JIM HAWKINS' RADIO AND BROADCAST TECHNOLOGY PAGE|