Project Boxs

Finding a nice enclosure to build your projects into can be a problem.  The cost of those ‘mini boxes’ I used to buy as a teenager have gone up by an order of magnitude or more over the past few decades, perhaps more than the cost of living indexed by inflation.  Not withstanding the fact that those ‘mini boxes’ are ugly things that look nothing like the ‘store bought’ versions of what we’re trying to home brew, there must be a better way.

There ARE some nice professional project boxes out there, but they are rather expensive.  I can’t see spending upwards of $100 for a project box to build a little QRP transceiver or other ham radio project in.  If you are thinking small, there are some nice ‘clamshell’ plastic cases that either snap or screw together.  Some of these have a removable door to a battery compartment.  I built my LC meter into one of those, the cost of that enclosure was reasonable.
The box that I built my Heathkit HD1250 dip meter clone into was one of several LMB royal blue project boxes I got a few years ago at a ham flea market.  I think they are still being made, and their cost new is a bit lower than a kings ransom.

If you are willing to perform a “Macgyverism” it is possible to create some nice custom project enclosures out of cheap materials you might have lying about.  Many hams have built custom project boxes by soldering printed circuit panels together.  This only works if you can obtain the material cheaply in bulk.  I ran across a source of badly tarnished PC board stock measuring about a half a yard by a yard in size.  Some pieces were single sided, others double.  Most were ‘standard’ thickness, but there were a few double thick panels in there, as well as a few that were ‘paper’ thin.  Most were fiberglass, but I also got some phenolic panels.

When soldering single sided panel pieces together to make an enclosure the copper clad sides would normally be on the inside of the box.  This will provide a good ground plane for the circuitry, as well as a Faraday shield.  The outside doesn’t need the metal surface, it’s going to be painted anyway.  You will need to use double sided panels in a few places, so save their use for where it matters.   There are many examples of project box construction on the Pic-a-Star project pages.

I made an experimental project box that was to serve as the enclosure for a proposed QRP rig I wanted to build.  The idea hit me when I found an empty one gallon metal container in the garage.  It was a little dented and rusty, but once treated with a rubber mallet against a two by four, a little steel wool, and some paint, that would not be a problem.  The top and bottom of the can were removed with a can opener (also a file and lots of elbow grease).  I then cut it in half the long way, and then proceeded to make a chassis with front and back panels from PC board stock.  The photos show the result.

gallon_rig3

gallon_rig2

gallon_rig1

The front panel and the paint job were inspired by the Heathkit SB series styling.  I’ve since replaced the microphone connector with a 5 bin DIN type, and added some rubber feet to the bottom half of the enclosure.

I haven’t yet actually built anything into this enclosure, what you see is a mock up so far.  The current project I’m working on will fit into a smaller enclosure that I made from a half of a surplus box thrown out by a former employer.  The paint can box will probably get used in a later radio project once I’ve proven out some of the circuitry I’m currently experimenting with.

The idea here is to make do with what you have on hand.  I bought myself a cheap sheet metal bending brake from Harbor Freight, and I’ve used that to form surplus sheet aluminum into box lids and chassis.

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s