Allows you to mount a 12v computer fan to a tube my plan is to use it to provide air flow to the bbq to help it heat up faster. Added new version of scad file there were probably some problems with the original with certain variables. Now added the ability to generate a battery compartment and handle, the included parameters are for a PP3 battery. Now has cut out for a square slide switch and things should create correctly if you change the sizes. You can also use this file to generate just a fan block by setting add_battery_holder to something other than true, you can use false but sausages will have the same effect.You can vary the settings for your pipe width and fan size. I've not included any screw holes I used the fan as a guide and then screwed the screws into the pla after drilling a pilot hole. The pipe I used was one of the ones supplied with a henry vacuum cleaner.