These are functional parts on the Austin A30 and A35. Like the original they provide a barrier for water to enter the car via the hole for the handbrake. These were made before by another clubmember, but I have not seen any for sale in a long time and decided I would have a stab at making them. As always, I started with a 3D printed mold. Here I explain how I went about doing this with pictures below. I will also talk about the pro's and cons of doing it this way.
First task is to model it in 3D
My first attempt at a mold. However I did not account for the enourmous adhesion between the PU rubber and the plastic. I had to destroy the mold in the proces of getting the part out.
I broke the mold getting the part out, you can see the infill!
My solution was to make the inside mold out of multiple pieces that can be taken out because of the reduced contact area. This is one aproach, a better one would have been to make the mold out of silicone rubber. Silicone does not stick to a lot of things.
Pouring them together with the mudflaps
The final product
checking fitment
I include 3D printed half collars to glue on the axle, this provides a good seal and a running surface for the rubber cover, protecting the paint.
Installed with collar
Without collar
