Rally arms for Tamiya M-chassis

Curved suspension arms, nicknamed “bananarms”, designed for use on MF-01X or M-05Ra - however, design should be compatible with other Tamiya M-chassis with same suspension design, because outer dimensions are identical to the stock arms.

I modelled these arms after struggle with damper settings on my MF-01X. The design lowers the bottom damper mount and moves it closer to the inner hinge pin, increasing lever on the damper, which results in softer damping and longer suspension travel.  It also moves the bottom damper mount rearwards, erasing need for spacers under the top mount and providing more space around the front wheel.

Assembly tips:

To achieve maximum ride height and suspension travel, use with M05Ra/MF-01X C-hubs and 55mm dampers in stock top mounting points - use of alternative upper mounts will cause non-linear spring force.

Depending on damper type, modification of lower spring cup (cutting) might be needed to clear the arm - unfortunately the space is limited and other solutions would limit suspension travel.

To increase strenght of printed parts, I recommend using Tamiya #53301 Suspension shaft set - these will clamp the arm in Z direction, acting as a reinforcement.

Hinge pin holes may require cleaning/drilling for free hinge pin movement. 

Printing:

Print upright, staying on “rear” flat surface - the print files should be in right orientation. Print with atleast 4 perimeters. Supports are necessary. Due to the use case, more impact-resistant materials are necessary - I had relatively good results with ASA, nylon would be probably the closest to the original part. PETG can be used in less demanding applications.