> For the complete documentation index, see [llms.txt](https://hrftank.gitbook.io/hrftank/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hrftank.gitbook.io/hrftank/ii-build-manual-hull-and-chassis/2.-suspension.md).

# 2. Suspension

Most armored vehicles use torsion bar suspension. Unfortunately, replicating it in an RC model is quite difficult (of course, you could buy a ready-made chassis — like one from Heng Long — and take it apart, but what's the point in that?).\
Besides, even though it realistically mimics the suspension movement of a real tank, its travel is quite limited.\
In my project, I wanted the vehicle to have good off-road performance, so I decided to design a suspension system inspired by the Christie type.\
This type was used in tanks developed before the outbreak of World War II — for example, the T-34.

The suspension I designed consists of **10 3D-printed suspension arms** fitted with simple **shock absorbers** designed for 1/8-scale RC cars. It provides **30 mm of suspension travel** and **70 mm of ground clearance**. Adjusting the spring preload or replacing the springs with ones made from a different wire diameter allows the suspension to be tuned to the weight of the HRF Tank.

<figure><img src="https://673609632-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FhmKl11OGPwbKiNEUvA5L%2Fuploads%2F7GvAHoKmPDCsovCHuRAx%2FDSC_7000.JPG?alt=media&amp;token=97621acd-2df3-4a8c-9ecf-bf854fc85f5c" alt=""><figcaption></figcaption></figure>