[Elecraft] QRO

[David F. Reed]

Brian,

In the past, there were 3 basic options; I suspect they are the same today:

   1. Buy a standard sized box to use as the chassis; use a drill press
      to drill small screw holes after your layout is determined and
      inked in the box.  Use a chassis punch set to cut the larger
      holes, and so on.  Buy other pieces of metal and cut to fit.

   2. complete a drawing package and take to a small metal working shop
      that has a metal brake to bend sheet metal, and the the parts
      formed for you from sheet metal you provide or buy from them; I
      like to us 6061T6 my self, because it is easy to machine, form,
      and weld if needed.

   3. Get a small metal brake, shear and drill press and do it all
      yourself.  It can be the cheapest solution if you find you made an
      error in your drawings, want to add something, do another project,
      and so on.

   4. You may want to make an exact copy of a handbook amplifier the
      first time out of the gate, to get this part of the process under
      control, and that may even yield a source of drawings for you,
      making (2) or (3) easier for you.

It can be a very fun part of the process as well; there are many tricks 
you can use to detour around the stuff you don't have; for example, if 
you don't have a brake to bend those nice  curved corners, you can cut 
all the parts with a shear, and use right angle stock along the inside 
edges; counter sink the screw holes on the outside, and you get a very 
presentable cabinet as well.

These methods of getting the sheet metal work done have served me well 
for five decades, and I am sure others can provide refinements and 
additional suggestions.

73 de Dave, W5SV

Brian F. Wruble wrote:

> I have always wanted to try building one of those big amplifiers. One thing
>that stops me is that I have no idea where you get or how you build all the
>"sheet metal" parts --- complicated pieces of chassis, etc.  Anybody out
>there who knows how people manage to build or source these?
>  
>