Z scale
Last changed: 2013-05-09

Foot path lantern

This model is currently not available.This model was recently considered unprintable by shapeways. An updated version did print successfully, but I could not remove the support structure, I broke all 10 lanterns when trying it. I will make it available again once I have a working version.

Here is a model of a foot path lantern. It can be lighted with a small 0402 LED. This model is relatively easy to assemble and paint, a good first model with LED, especially when the LED already has wires attached to it.

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General info on the materials used

The material for all my models is called Frosted Ultra Detail by shapeways. It is printed in a process called Multijet Modeling (MJM). The model is printed in layers which are hardened by UV light. There is also a wax like material used as support material. Most of it is removed directly after print, but on some models it is stuck inside the holes and has to be removed before assembly.

At room temperature the Frosted Ultra Detail is inflexible and breaks suddenly without warning. Thinner parts break off very easily, so please handle all models with care. It gets more flexible when heated, but still breaks suddenly without prior warning. It is possible to very carefully bend it into a new position while warm. The Frosted Ultra Detail will retain this position when cooled, but when warmed again it will bend back to its original position.

The material can be cut with a sharp knife. Often small splinters will break off at the bottom of the cut. It is possible to smoothen the surface by sanding, I usually use a nail file.

The Frosted Ultra Detail material can be glued together with all-purpose glue and with super glue. As super glue I prefer the liquid one since it sets so fast. I use it mostly on parts which I fix in position before gluing. For stuff that needs adjusting before the glue has hardened I use all-purpose glue.

For painting the Frosted Ultra Detail material shapeways recommends acrylic paints. There are some reports in the user forums where models in Frosted Ultra Detail started to melt and smell when painted with non-acrylic paints, so I decided to follow the recommendation to be on the safe side.

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Using LEDs for lighting

A lot of my models are designed to be lighted by 0402 LEDs. To connect them I use emanelled copper wire of 0.1 mm diameter. Any thinner wire I tried dissolved when soldering. For models which use only one LED it is possible to use thicker wires.

To simplify the threading through the model I twist 2 wires together. I take 2-3 meters of the wire and stick both ends to something like a table or cupboard. Then I try to keep both wires parallel until I reach the end of the loop. This I put into a miniature drill and slowly twist the wires together. Be careful when taking the cable out of the drill, it will try to twist back and create a big knot. It is better to make several shorter lengths than 1 extremely long cable.

Soldering the wires to the LED is not an easy task. I try to stick the LED onto double sided adhesive tape, but they are so small that they don't really stick to it. I use a very fine tip and try to solder both wires at once, but it is also possible to solder them one after the other.

The LEDs I use

Here is a list of LEDs the I use as an example. Depending on where you live you may need to do some research on where to get similar ones.
Osram Firefly® LW VH8G Cold white A general purpose white LED. This is officially a side LED, put has the soldering pads at the bottom as usual.
Victory VS 1WD9M Cold white Another general purpose white LED.
Everlight 16-213UYC Yellow A yellow LED for traffic signs and traffic lights. It is a lot dimmer than the other LEDs on this page, but I did not find a brighter one. The LED color amber is no substitute, it is too red.
Everlight 16-213SURC Hyper red A red LED for traffic lights. The hyper red LEDs are a lot brighter than the normal red ones, but are nearly identical in color.
Osram Firefly® LT VH9G True green A green LED for traffic lights. Don't use a normal green LED, they are too yellow, the 525 nm true green ones are much better.

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Cleaning Frosted Ultra Detail

To remove traces of the support wax and the oil which is used to remove the wax on the Frosted Ultra Detail material I use a small ultrasonic bath filled with water and a drop of dishwashing detergent. I usually put the models in for 30 minutes with a change of water after 20 minutes when necessary.

Sometimes there is a white powdery stuff on some parts of the surface. This seems to be a mix of the support wax and the material. As far as I know the only way to remove it is by sanding or scraping it off.

Separating the parts

All 10 lantern poles and all 11 roofs are held together with support struts to make cleaning and handling easier. The picture was taken after cleaning.

Use a small hobby knife to separate the lanterns and roofs by cutting through the struts holding everything together, shown in blue in the picture. Remove the rest of the struts either by cutting them off or by carefully sanding the surface.

Painting the roof

Paint the underside of the roof in white at least 3 times to avoid the LED shining through the roof. Any light not blocked on the underside has to be blocked by the paint on the top side later.

For easy access to the underside I stick the roof with small pieces of double sided adhesive tape onto a piece of tissue paper.

Cleaning the cable channel and inserting the LED

Make sure there is no support wax blocking the channel in the middle of the lantern pole. To remove any carefully heat it to about 60-80°C while pushing a small wire through. Clean everything with degreaser once the wire is through.

Thread the wires of a white 0402 LED from the top through the channel. Add a small drop of all-purpose glue to the underside of the LED and pull the cable until the LED sits tight inside the lantern. Fine tune the position with tweezers and let the glue dry.

Gluing the roof

Add a thin layer of all-purpose or super glue onto the top of the lantern post and glue the roof in position. You can use both type of glue in this step, the all-purpose glue allows some position corrections, but needs time to set. With the thin super glue you cannot correct anything once roof and base had contact, but you can continue immediately with painting.

Painting the finished model

Paint the lantern pole up to the LED housing. Also paint the top of the roof. You may need more than one coat of paint, connect the LED and check for light coming through where is should not.

To make the LED housing more transparent you can apply a thin layer of oil to the unpainted parts. Thin machine oil and melted vaseline works equally well.

Links and downloads

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