the Miniature Turbojet Engine Rendered in 3D

[WebPilot]

Nothing new to add. I just felt my last post was prematurely
'pushed off' the 'Last post in Forum' marquee by someone, you
all know, who obviously doesn't know how to edit and made 7
posts on his own thread within 24 minutes.

Give the other members a chance to say something, too!

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... and now you don't.



According to the plans, the end of the shaft is not threaded.

[Zippiot]

looks great!

[WebPilot]

Thanks, Zippie. The best has yet to come.

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Here are the beginnings of the compressor housing.

[WebPilot]

Holes have been 'punched' and I have included one machine
screw.

From the dimensions given in plans, I have surmised that
the machine screws are #4 UNF series (fine thread). Screws
penetrate the compressor housing without engagement; the
threads are in the sheet metal of the rear impeller housing.

I like using allen wrenches so the screws I have drawn are
ANS hexagon socket head cap screws. They are a bit of
a pain to draw properly.

[WebPilot]

I allowed my colors for this new addition to the model to be a 'default
scheme' and was quite surprised to see this. The compressor housing
looks like it's made from plastic. And 'much to my wondering eyes should
appear' is that pretty 'metallic blue lustre' I want for anodizing aluminium.

The machine screws are not made from aluminum, but I may keep
the color anyways. Regardless, I shall remember and use it in the future.



NOTE: the 'double shadow' at the screw head in the 9 o'clock position.

[WebPilot]

ooooo ...

[WebPilot]

Well, not quite ... but the compressor housing is transparent here.

[WebPilot]

Perhaps the reader would prefer a tint ...

[WebPilot]

I adjusted the camera's location and rotated it, here, 90°.

[WebPilot]

The modified Testor #2 glow plug may have slots in the
'fin' area (instead of flats), where a special spanner is re-
quired to remove/install it ... dunno, for sure.

[WebPilot]

Here one of the 'plugs' is in place, and I am experimenting with a
technique to simulate a metal's 'cast' finish. This may come in handy
for future projects.

[larry cottrill]

Forrest, this stuff is just excruciatingly beautiful!

The "nubblies" on your "casting" are very fine-grained. I saw stuff that looked just about like that when I worked in the jewelry shop. Jeweler's casting sand is very fine, like aquarium sand or something. The big aluminum alloy castings my dad got made for me (for telescope mountings) were MUCH rougher. They were done in a big foundry, where everything is "heavy duty".

The Testors plugs I used to get occasionally were "standard size" hexagonal, though they did have the double groove lathe turned all around. And the gold plating, of course. I never ran across any that required a special tool for tightening them down.

I love seeing this work progress, though I seldom say anything about it. I think many of us find this quite fascinating to see unfold in this way. Even your occasional "glitches" are highly instructive. Accurate rendering in three dimensions is obviously not a simple matter.

L Cottrill

[WebPilot]

Forrest, this stuff is just excruciatingly beautiful!

Geeze Louise, I don't mean for it to be 'painful'.

I am glad to read you are viewing these images in all there splendor -
they are near 'photographic' quality. I've been on other computers and
realize the graphics hardware is not 'set up' correctly or the machines
have inferior graphics cards/drivers.

The Testors plugs I used to get occasionally were "standard size"
hexagonal, though they did have the double groove lathe turned all
around. And the gold plating, of course. I never ran across any that
required a special tool for tightening them down.

I have several model airplane engines sitting around here and most
all do have the 'hex headed' glow plug for removal.

From the plans, I surmised a special wrench - like the sheet metal
wrench used to remove the head from the barrel - was required for
these. A wrench like this was used to remove the head/glow plug from
an old Cox .049 engine - since the head and glow plug were integral.

I love seeing this work progress, though I seldom say anything about
it. I think many of us find this quite fascinating to see unfold in this
way. Even your occasional "glitches" are highly instructive. Accurate
rendering in three dimensions is obviously not a simple matter.

It just takes time to get 'good at it' - just like operating a welder, lathe
or milling machine. Then all of a sudden, things begin to progress
smoothly. The nice thing about it is that you are rewarded with
something tangible for all the effort one puts into it.

Thanks again for the compliment.

[WebPilot]

Drawing a simplified bearing

1. draw the outer diameter and inner diameter as cylindrical
   surfaces
2. along a radius, draw a vertical rectangular area joining the
   two (this will later become the cross-section of the bearing races)
3. draw a ball bearing here, with its center located at the centroid
   of the rectangular area.

PS This somehow strikes me as some kind of spiritual
symbol.

[WebPilot]

Now,

1. take the sphere and punch a hole through the vertical
   rectangular area (using the BOOLEAN function)
2. select some vertices (symmetrically) on either side at the
   median line
3. delete them leaving cross-sections for the upper and lower
   'races'.