Schoolhouse Lights

How it started …
I was talking with Bill Gill one day about the possibility of whipping up some HO scale light globes for him and his cronies.

Image1(…) think about a project that’s been on a back burner for a long time: making some “schoolhouse lighting fixtures”. You can see a multitude of styles with a Google search, but below are three extremely typical examples that I like.

These fixtures were/are still pretty common in many stores as well as older schools and other commercial places. I have (or at least had) someone willing to cast some of them for me in transparent and milky resins HO scale if I could come up with some masters for making the molds.

Greg did a SBS on the procedure for Railroad Line Forum – HO scale school light globes.

..response
Not having much experience in casting resin from molds I simply told Bill that creating the 3D mesh wasn’t a problem. Some concern was expressed about the slight ridges left from the 3D printing process to which I replied that .. if they showed slight sanding would fix that. Bill in returned expressed his worry that such sanding might create a problem with shadows etc. This is the kind of thing that come up with we lack the experience with doing such things .. and may produce ‘experts’ who can reply “Oh no1 .. blah blah” .. once we have screwed up enough times. Ha.

So .. my suggestion was .. “Let’s produce a sample of globes and see how they come out – we may be able to use the 3D prints themselves and bypass the molds/casting entirely.“.

Preliminary Design
unnamedI used the photograph to the left for my initial drawing. I simply brought it into Sketchup as an image so I could trace around it to generate a pattern.
oneTo be honest .. what you do is trace one side and mirror that. Still .. I came up with this which I scaled to 4.68mm dia (this is 0.184″ .. which is 16″ dia. in HO scale)
Version1After a bit of discussion we decided to leave off the cap and just leave a short stub up on top. Since this was to be a sample to ‘play with’ .. I inserted a small starter hole for a drill.
Version 1
uncleaned2-900So. I went ahead and uploaded that version 1 mesh as an array and had a test run printed. To save on handling and shipping I added these to a set of double-head bitts I wanted for myself. I then sent these on to Bill Gill so he and Greg Shinnie could ‘play’ with them. For the next bit .. I step aside .. and let those two do their thing.
Lighting
lightedNow .. the ‘magic’ starts. Greg Shinnie used products from Ngineering.com to light the globes.

He used their .018″ Stainless Tubing, one of their HO Baby Moon Hub Caps for the cap on top of the light and finally their NANO LEDs .. drilled a 1/16″ hole half-way into the globe and .. had light.

Greg did a SBS for Railroad Line Forums – HO scale school house globes.

Version 2
16inThis version I created the 1/16″ hole (1.63mm) and hollowed the globe.
6eaRenderI arrayed six ea on a short sprue. This is needed since that is a minimum size for printed objects at Shapeways of 5x5x5 mm.
60easwrenderI put up various arrayed globes on my Shapeways store .. 30, 60 (shown), 120 and 240 arrayed globes. Note that these are in “BETA” having not been printed yet. I have them linked from my website: HO 16in Schoolhouse Globes.

If I can ever get all my ducks in a row .. with the pigs lined up behind them .. I would like to get all the pieces together .. globes, LEDs, tubing, caps and sell them as a ‘kit’. That’s still .. just a thought for now.

O Scale Version
Goto the next page for the 1:48 Schoolhouse Globes


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