K7QO's PCB Case Construction

This is a series of photographs and descriptions showing how to construct cases for QRP projects using PCB material. This process is as old as PCB material, but maybe, just maybe I can give you some ideas to improve the quality of our workmanship.

I am also trying some experiments here to determine what process I want to use for small not-to-be-seen-by-another-human and those that are for show and tell at QRP gatherings. So the work seen here is just test pieces to demo the different techniques. I recommend you sacrifice some PCB material to experiment and determine what works best for you. Education is expensive no matter how you get it.

With the introduction of the AZ QRP Group Tuthill 80 transceiver, a number of people were introduced to this technique by Ken LoCasale, WA4MNT, with an article for the yahoogroup that was formed. I modified the fixture by going to a corner piece and clamps to keep alignment. If you find that you don't get 90 degree alignment, then modify the fixture to correct for cooling effects after soldering pieces together.

The first thing you need is a fixture made up of wood. I use 1/4" scrap MDF (medium density fiber) board, but any 1/4" material or even thicker should do nicely. I cut three pieces to form a "corner" shaped piece. I then glued the pieces together using Titebond II. It is important to make the angles all 90.00 degrees. Take your time and measure and measure and then glue and measure again. Not rocket science.

  • Wooden Fixture.
  • Two Pieces of PCB. Here we have two pieces of PCB to work with. One is double sided (DS) and the other is single sided (SS). I am experimenting with the two kinds to determine if the outside of a case makes a difference as to whether it is plated or not for finishing techniques. And I learned something doing this.
  • Back Side of PCB Material.

    I have experimented with different methods for cutting printed circuit board material and I find a shear to be the best thing. I bought this shear from Harbor Freight in 2010 and I only use it for PCB cutting. If you are lucky, you can find it on sale for under one hundred dollars (US) aperiodically. Look out for their ads and check online.

  • Harbor Freight Shear.

  • Film at 11 demo of shear. Nothing serious. Just a small piece of scrap material used to show motion of the cutting edge of the shear.

    You must have a good right angle for cutting and measuring PCB material. The next photo shows the right angles for the wooden fixture.

  • Right Angle.
  • Checking 90 degree angle for corners of PCB.

    The next two photos show how I check for parallel sides using the right angle.

  • Measure Distances between opposite sides.
  • Measure Distances between opposite sides at the other end.
  • Two Pieces to be joined together.

    After making the pieces to be joined together, I clean them thoroughly with steel wood pads embedded with soap. You use what you prefer. I get 18 pads at the dollar store from time to time as needed. Take the piece that is to be the end of your case (the lower half) and clamp it to one end of the fixture. Make sure it is against both the bottom and the side of the fixture as shown. Especially after you clamp down on it. Make sure the clamp doesn't shift the piece.

  • End Piece Held with Clamp.

    Now clamp the bottom piece in place. Again, make sure that the left side is against the fixture and the end is in good contact with the vertical PCB material. This insures excellent alignment and reduces sanding when done.

  • Two Pieces Snuggly Clamped Down.

    I solder a small blob about every 2cm along the edge. Make sure you do not do the ends, as there are two pieces that must be soldered to make the case rigid. I use a 23W soldering iron that I use for everything else to do the soldering.

  • Solder Points up close and personal.

    Now make a small rectangle or square piece of PCB material. Square if you want 45 degree angles for the side supports. I did this with a rectangle piece to demo the two ways that non-45 degree angles can be used. And I learned something else in the process. The end pieces must be double sided board if you are not doing 45 degree angles.

  • Rectangular Piece.
  • Diagonal Line where board is to be sheared.
  • Resulting two triangular pieces.
  • Cleaned up and ready to solder in place.

  • Piece in corner. I turn the fixture on its side. You may want to use another clamp or just hold it in place being careful not to burn yourself with the soldering iron. Practice to determine what works for you.
  • Side Support Soldered in Place.
  • Outside shows excellent alignment.
  • Other side support in place and soldered.
  • Another View.
  • Photo showing both supports. Here I wanted to show how non-45 degree angles on the two supports allows you a choice. I had to do this because the piece was single sided. Double sided material would allow me to do both with the same orientation relative to the front panel.

    Once you get the chassis completed, you have many options for the finish. I wanted to experiment with using printer paper and a laser printer for panel art work. I went to the computer and brought up OpenOffice Draw and quickly made a front panel layout. This is for demo purposes only and I would spend more time on a real project, if I wanted it to be nicer.

  • Front Panel Printed Out.

    Now remember when you were in the first grade and you got to use a pair of scissors and some paper and learned to cut along the lines. Surprise. You get to apply it here. I used scissors (you could use a paper cutter) and cut the front panel out so that it would align along the bottom edge and left side of the front panel. I laid it down in the fixture as shown in the next photograph. Make sure everything is clean.

  • Front Panel Paper snug against the edges of the fixture.

    I took the chassis to the garage and lightly sprayed the front with some contact cement. Let it dry the time needed per instructions on the spray can. Make sure you mask off things that you don't want to get the messy stuff on.

    Now, very carefully lower the chassis onto the paper front panel using the fixture to insure good alignment. As shown in the next photograph.

  • Panel in contact with PCB material.

    Very carefully trim the edges around the panel with a razor blade to neaten up the assembly.

    I don't need to remind you just how dangerous a single edged razor blade is. Put it away and lock it up and keep away from kids, pets, significant others, enemies, etc.

  • Here is the result.

    I wanted to make the front panel glossy, so I very carefully put a very very thing coat of clear Krylon (I use the cheap stuff at Wal*Mart in their paint department that costs a little over a buck a can. A single can goes a long way for this stuff.

    I did the first coat, shown below, very very lightly in order not to cause the toner to run and ruin the work. I'm going to do several very light coats over a period of a day or two to make sure that I don't ruin the toner on the paper.

  • Front Panel with light coat of clear.