Crocodile Locomotive With Working Brakes 3D Model

A small toy crocodile locomotive with opening doors and roof, and real working brakes. This locomotive fits popular brick figures.

All elements are very easy to print even for begginers (do not require the use of supports). All parts are ready to print on the smallest 3D printers (min. required printing area 80*80*75 mm).

All our toys are designed to be fun, they have many interesting functions: opening doors, hatches, holds. You can print and build toys together with your children – there are many parts and screws that give a lot of fun.

Needed parts or materials (suggested, you can use other matches parts)

• 75 pieces M2.2×6.5 screw (DIN7981),
• cyanoacrylate glue (not essential but may be needed to glue the wheels to the axles).

Optional parts

• the locomotive is prepared for assembly of a set of lights (6*white LED 5 mm), you can also use white LEDs as an imitation of reflectors (even if you do not intend to connect them to the battery),
• the electrical cabinet is prepared for the installation of four PCB 7*7 mm switch ON/OFF, batteries can be placed in the noses of the locomotive.

3D printing

• We recommend using PLA filament, nozzle 0.4 mm and layer height 0.2 mm, but you can test other settings.
• All files are in print-ready positions, you don’t have to rotate it on your slicer.
• The elements are easy to print and do not require the use of supports, brims or rafts (the only exception is axle-with-spline.stl, which prints vertically, and for this we recommend a small brim).
• Print all elements with 100% filling (the locomotive runs better if it is a little heavier, the differences in time and filament consumption when printing with a small filling are not significant).
• You will find all cabin windows in the croc-windows-all.stl file, but you can print each one separately from croc-window-***.stl files.

Assembling of parts

• If you don’t want to use LEDs, you can use lamp-instead-of-LEDs.stl file instead.
• The sizes of the wheels and axles should match, but if they are too loose, try to stick them with glue. You can also slightly chamfer the ends of the axle with a regular sharpener.
• If the axle is too thick, you can gently sand the hole in the wheel or you can very gently change the scale of the axle-with-spline.stl file when cutting in a slicer (change the scale of the element only for horizontal, the vertical scale should remain at 1:1). We have designed a special wheel and axle assembly tool, you can print it and use it to make your work easier.
• Make sure the opposite wheels are turned 90 degrees (there is a small marker on the axles to help you with this). This is very important because if the angle on any of the axles is different, the wheels will jam. You can also use wheels without rods from the wheel-without-coupling-rod.stl file.
• Try not to tighten the coupling rods coupling-rod.stl. They should be free and easy to spin. If the coupling rods are too tight, you can slightly enlarge the holes in them.
• Before assembling the cabin, check that the brake lever turns freely.
• Use pieces of filament 1.75 mm to attach doors and roof.
• Pantograph files are located in a separate pantograph-v1 folder.

Maintenance

The axles of locomotives and wagons are plastic, so after long-term use, the vehicles may experience greater resistance and may creak while driving. To extend the time of trouble-free operation, we recommend lightly lubricating the axle with Teflon grease.

Backward compatibility

On June 26, 2022, due to the adaptation of trains to run on rails, the method of mounting couplers was changed. To enable connection of older wagons with newer ones, the new version of the coupler-automatic.stl and coupler-automatic-cotter.stl files should be printed and installed in older wagons. (files are available in the free locomotive model). You can also turn all couplers on older cars upside down, but this is not recommended – trains running on the tracks will not fit well into the turns.