50 Watt Plexi - Machine Head

Here’s what some of the parts looked like before finishing. The end pieces are made from 1/4" 6063 T6 aluminum plate. The chassis is .080 3003 aluminum sheet metal cut and bent into shape with 1/4" plate welded into the ends for the roll cage end plates to bolt to.   

The slots were cut with a 1/2" end mill on a Bridgeport (see shop pics) then the inside edge was treated with a 60 degree chamfer. All the bolt holes were drilled and then counter bored so the allen head cap screws would sit flush with the outside of the end plates.

Here are some of the aluminum parts after final finishing and anodizing. The aluminum knobs were bought from a supplier but to separate them from a stock unit I chocked them up in a lathe and put a different profile on them and chamfered the ends and anodized them purple. The feet were made from 1" bar stock, the profile was cut then I drilled the holes and chamfered the end of each hole. The cap can covers are described in a paragraph below. 

Here is a view of the inside of the amp. All top quality parts neatly wired, dual bias pots and 1 watt 1 ohm resistors mounted on the board to help with setting the power tube bias.

In this view you can see the custom covers I made for the multi cap cans. Believe it or not these were one of the more difficult parts to fabricate. They started out as 1 3/4" OD aluminum bar. The inside diameter had to be bored out to 1 1/2" to fit over the cap cans, this left a very thin wall to weld the tops and the tabs to. Once all the welding and finish work was done they were sent with the other parts to be anodized.