an rc car has been on my 3d printing to-do list for a long time. sourcing the right parts for the existing models proved to be difficult. hence i designed my own car.
this is the chassis for a 1/6 scale model of a volvo c30 that i intend to build. it has a total length of around 700 mm and a width of 300 mm. most of the off-the-shelf components are either from traxxas or hobbyking.
the design mainly consists of the front and rear assemblies that are attached to a base plate that holds all the electronics components. the 3d printed components have already gone through several design iterations because of crashes. but it has not been tested to all possible extremes. this is also the reason why this is a work in progress. i'll update the design after each improvement.
a few further comments:
- i only uploaded the creo elements express file so far since i'm constantly modifying the design. i will upload stl files once the design is robust enough.
- it's only a half model because creo elements express has a 60 components limit.
- i designed the spur gears with the planetary gear designer that can be found on my website.
- i print all components in abs with 3 shells and 20% infill.
- creo elements express is free to use and can be downloaded from the ptc website.
here are three videos:
further information on the project can be found here:
update 2014-07-18, version 166:
the motor pinion of version 163 is a stock part made of steel from hobbyking. the gear teeth are less than 4 mm wide so they tend to eat the 3d printed spur gear's teeth.
version 166 has a modified gearing system having a higher reduction ratio of 6.4:1 from the motor to the axles. additionally, the gears are around 10 mm wide. this should improve durability substantially.
there are now two versions of the spur gear in the model. one with zero play nominally and another with 0.2 mm profile correction that adds a bit of play.
update 2014-07-20, version 168:
gear reduction ratio increased to almost 8:1. this gives the model a better low speed characteristic.
update 2014-09-12, version 176:
improved directional stability thorough the addition of a 12° caster angle. higher turning speeds thanks to 3° camber.
each one of the gears has failed at least once recently while driving on a 3s lipo. the problem appears to be the low strength of abs. hence i'm finally switching to nylon (taulman bridge). this material is so tought, it's even a pain to remove support structures.
the following components are from traxxas:
- 2x ball bearing 18x12x4
- 2x drive shaft rear TRA6852X
- 2x front stub TRA6854X
- teflon fibre washers TRA1985
- 4x flanged nuts TRA3647
- 4x wheel hubs TRA1654
- 4x wheels TRA7473
- 1x gear set TRA6882X
the following components are from hobbyking:
- 10x ball bearing 10x5x4
- 2x ball bearing 15x10x4
- 16x landing gear wheel stop set collar 8x3.1mm
- 1x 14T3.175mm m1 hardened steel pinion (up to version 163), replaced with shaft for an EDF (part # OR003-00107-7B) in version 166.
- 4x 1/10 model car 100mm adjustable aluminum shock absorber
- 1x trackstar TS-415MG digital servo
- 1x turnigy trackstar waterproof brushless por system 3000KV/80A
- 6x nylon ball joint M3 x 24mm x 3mm