Customisable conversion adaptor cowlings for fans of any size

Files you will find for this product consist of STL files of some common conversions as well as custom jobs made on request, the beta OpenSCAD file for ease of customisation, an older version of the native SOLIDWORKS file and a newer version of the native Inventor file.

The OpenSCAD file is primarily for customisation. As of now it is a very simple and inefficient model but should be able to make simple conversions that are not already available.

The Solidworks and Inventor files can be used for customising with very basic constraints that work for most sensible conversions. The layout of the file should be easy to follow for anyone with basic knowledge of the required software.

Customisation

When it comes to low power fans there is a degree of de-facto standardisation, however this is not formalised in any way. The OpenSCAD should at least allow people to work quickly with non-standard fans as well as choose other variables to suit their needs better than my ready made adaptors can handle.

The OpenSCAD is very rough and unrefined and should be considered to be in early development. I am still coming to grips with the software and the language. However it should function fine when the size difference between fans is not too great. I will probably improve this as and when I get the chance.

As always, once created, make sure you check the resultant STL before printing it. Everything should function fine, but you can never be too careful. If the file doesn't work for you, or you need something special making, let me know and I will see what I can do, time depending.

The OpenSCAD file uses 12 variables. These are:

**holeaccess**
This dictates how you access the smaller fan's mounting holes. The options are:
Cowling: Small fan screws accessed through the cowling.
External: Small fan screws accessed from outside of the adaptor.
Flange: A simple flat plate with mounting holes for both sizes.
Some models work best with external access, some with cowling access, some it doesn't matter for. Experimentation is the best way to find the right option. The Customizer makes the "Cowling" and "Flange" options look messy, but they are fine once created.
**$fn**
This is the facet resolution and can safely be ignored.
**smallsize**
This is the smaller fan's given size. (e.g. 60 mm, 80 mm)
**largesize**
This is the larger fan's given size. (e.g. 92 mm, 120 mm)
**smallflange**
This is the thickness of the smaller side's mounting flange.
**largeflange**
This is the thickness of the larger side's mounting flange. This is also the thickness of the "Flange" option's flange.
**wallthickness**
This is the thickness of the wall of the cowling. The part that joints the two mounting flanges. This size is added twice to the small and large fan size to dictate the size of the mounting flanges.
**cowlingheight**
This is the height of the cowling between flanges. The total height of the adaptor will be this plus the two flange thicknesses. It is advisable to bear in mind the angle of the cowling when choosing a height, to ensure smooth and reliable printing and to a lesser degree, good airflow properties.
**smallholes**
This is the spacing between the screw holes on the small fan side. (e.g. 50 mm, 72 mm)
**largeholes**
This is the spacing between the screw holes on the large fan side. (e.g. 83 mm, 105 mm)
**smallholesize**
This is the diameter of the mounting holes on the small side. (e.g. 3.5 mm) Standard PC case screws tend to be around 4.5 mm, so bear this in mind when choosing your screw hole size.
**largeholesize**
This is the diameter of the mounting holes on the large side. (e.g. 4.5 mm)

As with the STL models, the default values for the openscad model are quite liberal and could be trimmed down if necessary.

The Meerkat

The Meerkat