I was somewhat frustrated that I could not easily buy air filter foam inserts for the common 25cc Chinese chainsaw. Sellers sold the housing, but no filter element in it.
So, the project is to make a template to cut a foam element that is a neat fit inside the housing.
Above is a sketch laid up over a picture of the filter cover. The template is made a little larger than the aperture so that the foam filter element compresses a little to fit.
The template is a guide for a knife to cut the outline, the inner hole having already been punched with an 8mm wad punch.
Above is a projection of the template to be made on the CNC router.
Above is the feeds and speeds calculation for the job.
Above L-R, T-B are a foam filter fitted to the cover, the acrylic template, the rear cover of the air filter assembly, and a spare foam filter cut from the template.