EMRFD Message Archive 2759

Message Date From Subject
2759 2009-03-04 12:30:47 timshoppa Sheet metal techniques for radio cabinets
I have loved soldering together pieces of PCB to make little enclosures, cabinets, etc. Been doing it for decades now and am pretty good at it.

But sometimes I really want to do up a cabinet with sheet metal (aluminum, brass, steel.) My level of sheet metal bending ability is pretty much confined to making two U's and then using some small angles to screw them together. The end result usually looks inferior to what I would've gotten if I had bought a minibox of the same size. And there's a substantial amount of flex because other than the angles that I've riveted on there really is no stiffness.

So I need to somehow upgrade my materials, tools, or most likely my skills to the point where I can fold something more complicated and with a lot more stiffness than a "U". I actually have a good assortment of tools, like a little brake and some nice punches that I also use on prefolded cabinets etc. So I suspect I really need to enhance my skills. Is there a keyword for a community college class that would clue me in on sheet metal techniques? I called around and some folks pointed me towards a local trade school with a program for HVAC duct-bending but is this my best choice?

2760 2009-03-04 13:00:47 Gary Johnson Re: Sheet metal techniques for radio cabinets
Tim, you're on the right track. It's more about knowing how than having fancy tools, believe me. I learned sheet metal (and much more) in my high school metalworking classes. Some junior colleges offer general metalworking, and perhaps they have a unit on sheet metal. That may come with full machine shop training as well, which you would likely enjoy. Another possibility is to seek out aviation schools, which offer airframe-related training including sheet metal fab for things like control surfaces. I took a welding class at an av school, and that was very well-taught. HVAC is a possibility. Though they tend to work pretty big, they also get into lots of tricky angles and curved surfaces and field joints. At the very least you would learn about geometry, layout, cutting, folding, hemming, and jointing in galvanized, aluminum, and sometimes stainless. All good.

Read: Search for "sheet metal"
2761 2009-03-05 19:51:40 chris_yipyap_com Re: Sheet metal techniques for radio cabinets
There was a short series of articles recently in Electric Radio magazine about sheet metal enclosure fabrication.


2765 2009-03-08 22:34:26 jr_dakota Re: Sheet metal techniques for radio cabinets
2766 2009-03-09 06:49:45 timshoppa Re: Sheet metal techniques for radio cabinets
2767 2009-03-09 10:19:30 rcbuckiii Re: Sheet metal techniques for radio cabinets

Not sure if you want to attempt to build a brake yourself or not. Have a look at this site. I haven't built it but it seems that it could be built with som effort and maybe some help from a local metal fabricati
2768 2009-03-09 12:33:25 michael taylor Re: Sheet metal techniques for radio cabinets
2769 2009-03-09 13:27:42 bobtbobbo Re: Sheet metal techniques for radio cabinets
2770 2009-03-10 15:16:42 jr_dakota Re: Sheet metal techniques for radio cabinets
2839 2009-04-02 13:29:44 Ashhar Farhan Re: Sheet metal techniques for radio cabinets
I use a slightly cruder method to bend aluminum sheets.

first, i score the line with a sharp instrument (the pointy bit in my
interchangeable screwdriver),
then, i switch to a flat head bit and hammer slightly along the line to be bent.
then, keeping the sheet with the hammered in line face down and
aligned with the edge of my table, i simply start pushing the sheet
a few knocks of the hammer usually suffice make the bend sharper.

- farhan

2844 2009-04-02 17:52:42 Sudipta Ghose Re: Sheet metal techniques for radio cabinets
To bend metal sheets I used a wooden hammer and a 4" vice. This
ensemble was used for last 30 years with an inherent yearning for
something more satisfying and better. Recently, I built the metal
break described by Cebik, W4RNL in QST and was amazed to find the
result and simplicity of the contraption. I was going to thank OM
Cebik, the antenna wizard for his ideas alas only to find that he is
SK now!