The AirExchanger Bottom Base
The bottom base sits below the spacers.
The drawing includes both a .81” and 1” circle for clearing the collet on the router. You can use a 1” for most routers and up to 2.2KW spindles.
I used a piece of 8” x 10” x .093” polycarbonate sheet stock. These can be purchased at any home center.
In addition to the plate stock you will need a piece of waste stock. (see below)
You will also need 20, #6-32 x 5/16” machine screws.
Feeds and Speeds
I used a 1/8” up-spiral two flute end mill with a 5/8” cutting depth.
Note that I also do a full finish path at 18000 RPM. If your machine can control the speed just set it to 15000 RPM for all the cuts.
Shown here I have secured my sheet stock and backer board with a series of table clamps.
I used a piece of MDF, 8” x 10” x 1/2” as a backer board. Notice that this is the same size as the sheet stock I used for the parts.
I start by drilling the 24 mounting holes through the sheet stock.
I use a 7/64” drill bit to drill pilot holes into backer at each hole.
I add a piece of tape to set the depth I need to drill. Use one of the 5/16” machine screws to help.
A 6-32 x 5/16” machine screw is snugly inserted into the holes shown below. These will hold the base and cutouts in-place while it is cut.
Place the 6-32 x 5/16” machine screws into the holes shown here.
Don’t place screws into the holes that are not marked or your end mill may crash into the screw heads.
I then machine the inside cutouts and outside profile.
I remove the protective cover and use my finger nail to remove any burrs.
The Finished Bottom Base
Your AirExchanger top base is complete. Set aside until you start the AirExhanger assembly process.