Printed front axle for Mercedes Unimog 1:16 model truck

thingiverse

Two years ago, I motorized a 1:16 scale Bruder toys Mercedes Unimog, fitting it with an Atmel AVR-based IR remote control. Due to its fixed front axle, I crafted a steerable aluminium profile front axle (pictured last). Recently, with access to a reprap printer, I recreated the axle in openscad and printed it. It features an adjustable tie rod and is controlled by a micro servo at the front (photos included), allowing for steering and tilting. The design follows the basic Ackermann- or A-steering principle. Reusing vitamins from the old aluminium profile axle, I retained ball couplings for the tie rod and the servo connector. However, the servo connector arm broke after a few days of operation; hence, I made it thicker and replaced the inner connector bar with a hull extending from the servo attachment point to the axle arm. Updated scad and stl files are available for download. The scad code is parametric and commented. Printable parts include the frontaxle_complete* files, along with _body, _armright, _armleft, and _servoconnector. The arms need to be printed upside down, while the left and right arms have a support column for cutting off after printing. If you prefer print-with-support in your slicer, disable the support option in the scad file. The servo connector attaches to either arm using an M3 bolt for steering and an additional 3mm alignment hole secured by gluing a short length of 3mm filament through both holes. All bolts and nuts are M3; nut traps on the axle arms accommodate nyloc nuts for wheel axles.