A plexiglass/perspex mounting for the MintyTime is easy to do, and provides a simple and elegant mounting which I like a lot. It is even easier than using an Altoids tin, and has the added benefit of exposing all the electronics when you look around the back, which is pretty cool.
1. What you’ll need:
- A small piece of plexiglass. Most sign making businesses have an offcuts bin where you can get small pieces for a couple of bucks. You’ll need about 5″ x 3″
- A jigsaw with either a metal cutting blade, or best of all, a floor laminate blade. I used a Bosch T101 Laminate flooring blade and it worked perfectly. These are available in “T503″ 3-packs. No additional finishing was needed.
- Your MintyTime kit and drill template, as usual. Assemble the MintyTime kit all except for the LEDs and switches – stop at the same place you would if you were mounting it in an Altoids tin. Please refer to the assembly instructions at www.mintytime.com.
- A piece of scrap wood for drilling into.
Tip: Leave the paper covering on the plexiglass as long as possible. It protects the surface, which scratches easily.
2. Cut and drill to size
Decide on how much space you want around the edges of the kit. I went for about 1/2 and inch. Using your drill template you can then decide how big your plexiglass needs to be. Set your jigsaw to cut straight up and down (no forward/ circular motion). Using a fence to ensure a straight cut, saw it to size. Cut slowly.
Now stick the drill template onto the front face of the plexiglass using (or either side if they are the same, which most are). I like to use masking tape because it is sticky enough to be useful, but not so sticky it is hard to remove. Place the scrap wood underneath the plexiglass to prevent tear out. Using a 3.8″ brad point bit in a drill press, slowly drill the holes as per the template.
It you drill too fast, the plexiglass will melt onto the drill bit, which is a real pain to deal with (guess how I know :). Go slow and lift the drill out/replunge when you are halfway through each hole, to clear the hole.
While you are in your workshop area, you might as well cut a base. I used a bit of wood with a slot cut into it, but pretty much anything will do.
Remove the template, step out of the workshop or your drilling place to somewhere with less dust, and remove the paper covering the plexiglass.
3. Mount LEDs
The is basically the same as mounting the LEDs into an Altoids tin. First, insert the LED sockets. I find rolling them between my thumb and forefinger helps make it easier to insert them. They are soft, so take care not to scratch them. You can use a cloth or the sponge the IC’s were shipped in to protect them while you push them in. Then insert the LEDs as usual.
Make sure that the LEDs all face the same way. The long pin is +ve, and will have to fit into the “+” hole on the board. Also remember that you mount the LEDs from the back of the board. As usual, take your time doing this.
Mount the circuit board onto the LEDs as per assembly instructions at www.mintytime.com.
4. Now for the buttons and battery pack.
Now that the board is mounted onto the plexiglass, you need to add the buttons, battery pack and light dependent resistor (LDR). I just cut the LDR leads short and soldered it sideways, and it works fine. (see the image above).
For the buttons flatten the pins out, solder a two short pieces of wire onto them, and then hot glue them onto the back of the plexiglass. Once that is done, snip the wires down to size if they are too long, and solder them onto the PCB.
Finally, solder the battery pack on and insert the batteries.
Viola! Drop it into the base, set the time (remember it is a 24 hour clock) and you are all done.