I produce a number of 3D printed Model Railroad models, all of these have been produced initially for my own purposes in modelling projects I am working on. I am not a manufacturer or distributor, this is a sideline to my hobby and I offer some of the parts I have designed through a Shapeways Store to benefit other modellers who may be interested. I do my best to answer questions from people who have purchased models, but the nature of the Shapeways system means other than having designed the parts, I am not a part of the supply chain, and can’t provide replacement parts if something breaks.
I have set this page up to provide me with a place to put instructions for handling 3D printed parts, and for instructions for models as Shapeways doesn’t easily provide a place to link to this in their store settings.
My Store can be found at the following link: https://www.shapeways.com/shops/sjgardiner
General Instructions for Handling 3D printed Parts
Tips for Working with Fine Detail Plastic (formerly Frosted Ultra Detail (FUD)) Resin 3D Printed Parts
The 3D Printed Resin marketed by Shapeways as “Fine Detail Plastic (Smooth/Smoothest)” (formerly Frosted Ultra Detail FUD/FXD) (called “FDP” from here on out) which most of my models are printed in is different from traditional styrene plastic kits. The material has several properties which are different from styrene in terms of strength and how it reacts to paints.
Cleaning the parts
If you have worked with FDP before, you will be familiar with the need to thoroughly clean the parts upon receipt. For paint and glue to adhere to the FDP Resin, the remaining “support material” from the printing process must be removed. You will notice when the parts are removed from the bag that they have an oily residue on them, and there may be build ups of the residue in corners or crevices.
Various techniques such as ultrasonic cleaners, 100% Acetone (Nail Polish Remover) baths and such have been discussed for cleaning FDP . In my personal experience, I have had the best luck with warm water and dish soap. When I have experimented with Acetone or other cleaners, I have found that it softens the materials and can cause fine parts such as the window frames to distort or break. I have found that a warm water bath under running tap water and some soap when necessary does the job for me.
When cleaning, the material will turn a white colour and lose the transparent appearance it has when received. This is normal and is not a sign of a problem, the transparency is a fake appearance from the support material residue, some parts will turn more white than others, you will know the parts are clean when they are no longer oily to the touch, and when any build ups of greasy looking material in corners has washed away. It normally takes a couple of minutes under running hot water in my experience to get most of the support material off.
The FDP material can be brittle because of the 3D printing process, which involves building up the parts using layers of material which are then cured by exposure to UV light. Because of this, parts which can be created may be more brittle and subject to breakage. Often the parts can be glued back together, however the best approach is to try and avoid breaking them.
When the instructions call for drilling, it is advisable to use a pin vice and drill by hand, using a small bit (#77 or #78) to drill an initial pilot hole, and then using larger sizes to gently ream the hole out to the desired size. When drilling, carefully support the material as best you can to avoid it cracking.
In my experience, a good Cyanoacrylate adhesive (CA) type glue will work to bond the parts provided they have been properly cleaned and any paint has been removed from the surfaces being bonded.
DO NOT USE ENAMEL PAINTS ON FDP !! It is not possible to use enamel based paints directly on FDP . The enamel paints react with the FDP and do not set, from past experience testing enamel paints, the parts can be tacky over a week later and the paint does not adhere to the material, but forms a kind of permanently tacky shell. The parts do not have this reaction to Acrylic paints, though some paints do form a coating which can chip off if the parts are roughly handled. I have used a variety of Acrylic paints, the paints from Tamiya, Trueline Trains, Testors Model Master Acryl, Pollyscale (if you can find them as they are discontinued) and cheap kids/artists paints from Michael’s all work and adhere to properly cleaned and primed FDP .
I highly recommend priming the parts before painting as a protective coat as well. I use Tamiya Fine Surface Primer for this. It should be readily available at most hobby stores. You will know if you have cleaned the part well enough after priming, as the paint won’t adhere if it isn’t clean. You can test by putting on a piece of low-tack masking tape like if you were masking to spray different colours. If the part wasn’t clean enough, this will pull bits of primer off no matter how long its set, trust me, I’ve done it more times than I’d like to admit.
Tips for Working with Strong and Flexible Materials