# 27. Axle Lid Design¶

Ready-to-use parametric axle_lid design kit. The axle_lid is a an assembly of three parts:

• annulus-holder
• middle-axle-lid
• top_axle-lid

To get an overview of the possible axle_lid designs that can be generated by axle_lid(), run:

> python axle_lid.py --run_self_test


## 27.1. Axle-lid Parameter List¶

The parameter relative to the external outline are inherit from the Gearring Design.

## 27.2. Axle-lid Parameter Dependency¶

### 27.2.1. Diameters¶

The following relations between diameters (or radius) must be respected:

cnc_router_bit_radius < axle_hole_diameter/2
axle_hole_diameter    < central_diameter
central_diameter      < clearance_diameter
clearance_diameter    < holder_diameter


### 27.2.2. Generated files¶

For a same set of parameters, you may need several flavour of the design such as a plate with a hole and the same plate without this hole. Instead of adding input parameters to select if the plate must have a hole or not, the both variants are generated. You just need to pick up the file you need.