High-tech modeling for garden railroaders

Part 4: Tips and tricks when using a 3D printer
Join the conversation and post your questions in our forum thread!

Let's look into some of the tips, techniques, problems and solutions pertaining to the use of a 3D printer. I don't have all the answers, but these are things I do to get great prints.

3D printers can be temperamental. Sometimes things just work great and sometimes nothing works. If you have a little technical background and know basically how a 3D printer works, you can often find the problem and maybe come up with a solution for your particular machine.

Heated Bed

You must have a heated print bed for printing ABS material. (This is not necessary with PLA material.) The temperature of the bed is typically set to 110°C. (230°F). An even temperature across the bed prevents ABS from warping while printing. Some warping might occur because temperature differences across the ABS material could allow contraction of the material. 

 The best way to  prevent warping is to use the heated bed and an enclosed printer, such as the printers from XYZprinting. Since a completely enclosed printer is protected by patents, you will not find many printers with this feature. As I mentioned in a previous article, I have used XYZprinting’s da Vinci 1.0 AiO printer with great success. 

There is a trick that I learned, though, while using a ROBO 3D R1 printer -- a user-built enclosure that goes over the entire printer. I tried it and it works quite well. I was also given another tip; put a large towel over the top of the printer. This will help to keep the temperature fairly constant in the print enclosure. I also tried this and it works!

Level Bed

The extruder head must be a certain distance above the heated glass.  I typically use a business card as my gauge. Each printer manufacturer has processes and procedures to level their print bed. You usually pick at least four points, then manually adjust the bed using the manufacturer’s gauge. An unlevel bed will result in poor prints or no print at all -- just a gob of goo.

Of course this is all mute if you have an automatically leveling bed such as the ROBO 3D R1 printer.

A sticky heated bed

To make sure the extruded material sticks to the heated glass, you need something that allows the extruded material to stick to the glass as the extruder passes it. The first material to try is painter’s tape. This works well but must be put on with care to make sure there is no overlap, creating a “bump,” if you have to use more than two pieces.

Some people use hair spray as the sticky substance. I have never tried this. My concern is that you would have to remove the glass to spray it.  Do not attempt this when the glass is inside the printer. The mechanism will not appreciate this substance on moving parts.

What I use right now is Elmer’s Washable School glue, sold in a package with several glue sticks. With a clean glass print bed, spread a thin layer of glue on the bed. Do not miss any spots.  Then you are ready to print. 

Once the print is done and the part removed, clean the glass with a clean, damp paper towel. Once the glass is clean again, you are ready to apply more glue and start another print. When you are finished, remove all the glue.  Do not store the glass with glue on it -- it is harder to remove later on.
Photo 1
Photo 2
Photo 3

Finishing the part

The first thing you should do is the same with any other plastic part; remove any excess plastic and file down rough spots. Take care doing this because the part is somewhat fragile, as all the layers have not fused together.

The printer applies layer after layer of material, one on top of another. These layers are fragile and can easily separate. Photo 1 shows the separation of the filament when I removed the part from the bed.  It is not easy to see, but if you look closely you can see the material bowing out slightly.

This can be easily fixed by carefully brushing a little Acetone onto the part while holding the separated part in its proper place (see Photo 2). Hold in place for about 15 seconds and you have fused the separated layers.

All layers can still easily be separated during installation or in hot/cold weather. To fuse all of the layers, I use an Acetone-vapor bath. I use a large, wide-mouth pickle jar, (Photo 3, without the pickles of course!). I also have flower frogs -- metal bases with sharp pins coming out of them. They look like small porcupines. I use a frog to set my part on. 

First, pour a couple of tablespoons of acetone into the pickle jar, insert the frog(s), then carefully place the part(s) on the frogs. Put the lid on the jar and set it in the sun for about 10 minutes. Remove the cover the jar lid at arms length (do not breath the fumes!) and let the part in the jar  air out  in a cool, shaded area. The acetone will have  fused all the filament layers together. After a couple of minutes the parts will still be a little sticky, so take care removing them.

The part should have a glossy finish with no visible filament layers. This part is now stronger, less flexible, and less susceptible to filament separation.

Photo 4

Extra tie plate

Often the plastic extrusions that hold the rails in gauge on commercially available track sections break. To make sure the track is secured to the tie, I designed and printed tie plates with my 3D printer (see Photo 4). I made them out of black ABS with two holes for 2-56, stainless steel, button head, hex-drive screws. The flat of the 2-56 head holds the track in place.  This tie plate is modeled after a tie plate that I use for the 7½”-gauge railroad. 

Please enjoy. If you need to order some tie plates, or would like some printed, please contact me or your favorite printer. Find a list of resources at the end of Part 2 of this series.

Downloadable File(s)


Read and share your comments on this article

Want to leave a comment?

Only registered members of GardenRailways.com are allowed to leave comments. Registration is FREE and only takes a couple minutes.

Login or Register now.


Get the Garden Railways newsletter delivered to your inbox twice a month

By signing up you may also receive occasional reader surveys and special offers from Garden Railways magazine. Please view our privacy policy