Schoolhouse Lights – part II

O Scale Version
16inHere is the initial design for the O Scale Schoolhouse Globes. That 4.539mm/0.179″ dia stud was just eyeballed in place and can easily be modified if needed. The 2.947mm/0.116″ dia hole is much the same – just a bit over the .7mm minimum wall size for FUD. The HO versions .. a 1/16″ hole was large enough for the NANO LEDs. has HO 15″ Moon Hub Caps. That is 0.172″. I don’t know what the ID of these is .. and here is what I am thinking.

I need to order HO 15″ Moon Hub Caps, NANAO LEDs, #38 wire and 0.018″ tubing. Rework the O scale globes to fit those hub caps .. have them printed .. and make up some ‘kits with bits’

O Scale 16″ Ver 3
HO_16in_Section_Ver3This is an attempt to fix some of the problems I had with earlier versions. Like always – the “proof is in the pudding” .. and it’s all ‘talk’ until I have a sample in hand. I haven’t even started to add attachments to sprues and array the darn thing yet but this should show some basics of Ver 3.

The globe itself is shown in green. The opening at the top is 0.071″ dia. This is to allow inserting a 1/16″ Nano LED into the interior of the globe. The cap (in blue) will slide over the neck of the globe with a slight clearance. The hole through that cap is 0.032″ dia for the wiring.

Image15The globes are designed to fit Nano LEDs. Greg Shimmie did this using LEDs from Ngineering. Me .. being a cheap type ordered some off of eBay. Here, they are called “Bright White SMD Led”. These little LEDs measure approximately 3.20×1.60mm. The wire leads .. about 0.28mm dia is about 200mm long. Forward voltage: 2.8V~3.4V, AC or DC. Forward current (typ/max): 15mA/20mA.
O_16in_Ver3Here is a concept drawing of one inside a light globe. The hole in the globe is 1.8mm .. the LED is 1.6mm so that is no problem. The wires SHOULD slide in behind the LEd. There is a smaller hole in the cap as I said, 0.032″/~.8mm .. again .. more than enough for the wires. If the lights are mounted on a tube (hypodermic) it will be simple enough to drill the cap out to fit.
resistorsAlong with the LEDs (20ea) are also supplied 20ea resistors. Blue | Red | Brown | Gold

That is a 620Ω 5% restistor.


Schoolhouse Lights – part II — 2 Comments

  1. I guess I am the only O Gauger on the RRL Forum that has an interest in your school lights.
    Seems many HOers want them though….

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