I settled for the final design, but before moving onto soldering part, I prefer to plan out and drill the enclosure. Once it’s drilled I can assemble all the parts and see how to fit the board in the end with all the wires. Once drilled I’ll also paint it to make it look pretty and unique.
Planning the Box
For this step, what I made is a SVG template. I have one for 1590A and one for 1590B type enclosures. SVG image format is great for this since I can use exact dimensions unlike in other common image formats. Btw, 27969PSLA box has very similar dimensions to 1590A. Here’s what I did for this pedal:
That diagram shows exactly where the holes should go. Once I print it, then cut it out, fold it and lay over the enclosure. It should fit perfectly. The red restricted area is showing 2mm wall thickness and where the screws go.
It’s not 3D, but works well as a template. I don’t know how to use CAD software, but I’m familiar with reading and drawing technical drawings (well, familiar is the word). All the drawing is helping me see from two perspectives (top and side) if everything will fit nicely together. For example, on that diagram above, I can see that POT outline and DC outline are overlapping when looked from the side. But I see from top that they will be side by side, they won’t overlap.
It also works well as hole template. I can actually use it to mark the holes pretty accurately. The actual file is quite bigger with templates for common components I use.
The component templates on the left are outlines. I included length of pins – if any, into overall width, length and depth of the outline. I keep the component templates on the left, outside of the actual SVG page. When I need a component outline, I copy it from the left hand side onto the box. I copy and place both top view and side view onto the box to see how they’ll fit. I use Inkscape for editing this file, it’s free but very powerful tool.
Before committing to the design, I normally print it out and line up all components just to make sure everything fits correctly.
I did not like the first attempt and I did a small adjustments to it:
You can download the zipped SVG from here:
Now that I have the template. I can place it over my enclosure and mark the holes. I use centre punch tool for this.
The template is over the box on that left hand side part of the photo, and on the right you can see where I punch the holes.
I’ll then drill the holes (following all the safety precautions, minding my eyes and hands most of all). I’ll drill pilot holes, with size 3 drill for example, then, if I have the correct drill size, I’ll go for actual hole sizes for each component. If the required holes are bigger I’ll drill with the biggest drill I have and then use unibit (a step drill bit) to get to the desired size.
I get the drill size that I need from datasheet. LED is easy – it’s a 3mm diameter hole. The pot needs 7.5mm diameter hole. Switchcraft jacks uses 3/8 inch thread, which is a bit over 9.5mm. I don’t have a drill bit big enough for this so I’ll need to use unibit. DC socket uses M12.7 thread – that’s 12.7mm, unibit. Stomp Switch uses M12 thread, unibit.
One unibit can drill a number of different holes. The bit is conical and it works in steps – as you go down it enlarges the hole to the next step, then the next until you get to the desired size.
Once everything is drilled I use a file to file out any rough edges, then clean the box from any dust.
Before I could mount everything, I had to break off a tab from potentiometer. I could drill a hole for it and mount pot with it but the hole would be visible and would not look nice. Easy to do with pliers.
This is how it looks when all components are mounted.
Painting the Box
The enclosure is now ready to be used, but it would be an awful shame not to make it unique, more personal, colourful, and that way more fun to play. Optional step, it definitely won’t affect the sound, that’s for sure, but I like nice looking stuff (to the best of my artistic abilities, that is).
Now, I could have used a pre-painted box, they come in various colours. That requires a bit more care when drilling, but even if I had it powder coated I’d still want to add something to it. Anyway, I really hope I’ll enjoy this ?
Roughly, the process I’m normally following:
- Sand & Clean the box
- Top Coat
- Paint some picture/design
- Lacquer/Varnish to finish it off
Sanding the box is not strictly necessary the surface is not too smooth for primer, but I do it anyway, just to roughen it up a bit for better adhesion. I mean, it says it so on the spray can … I follow the instructions … most of the time. And I clean the box afterwards.
There are several options for primer application. I normally use spray can. I like Montana Cans but I also have some grey primer that I got in a local car parts shop. I’ll use that gray one. There are some paints that don’t need primer. Also, I think I used a primer in a tin that I got in a local DIY shop once. I applied it with a brush. There are many options.
One thing that I learned is that metal primer is not suitable for aluminium, so either universal primer or aluminium primer should be used. Both cans that I have are universal primers. Off to a well ventilated area and proceeding with proper safety precautions … I mean, I just read what it says on the can and follow it.
That gray looks good and even, that’s why I like spray cans – they give me more even result. I did couple of coats, and waited for several hours for it to be completely dry.
While there aren’t too many options when it comes to colour choice for primers, top colour can be anything, really. For this, I have options – spray paint, tin paint, acrylic paints in a tub work too.
For this I’ll take out a brush and rob my kid of some water based acrylic paint tubs. The primer I used is compatible with this type of paint (I’d say nearly all are, but always read the instructions).
While the paint was drying, I was preparing final art design. To apply the final art, there are many options. I’ll do some hand painting. For example some water based paint markers (Posca) and also some “normal” (alcohol) markers (Sharpies). Ha, this is becoming mixed media art all of a sudden! I have some fine liner as well to draw initial design.
Good thing about paint markers is that they can be layered and so cover whatever is underneath them. Can’t do that with Sharpies. But anyway, whatever gives a nice result in the end will do.
I’m nearly there. This is looking better now. After all paint is dry, time to put the finishing touches with some spray lacquer (or varnish). This will seal the paint and add protective layer to it. Several coats will do, in this case I’m going to use lacquer from the local car parts shop.
That’s it, finished, looking good. I forgot how more smelly that lacquer is. Luckily the odour vanished after a day or so. That Montana varnish spray releases way less odour, another thing to think about for future builds.
Once lacquer is dry, lets see the fit once more.
Pot shaft is too long, I don’t like the look of it. Remember all my waffle about choosing the pot? Well, the truth is I wasn’t thinking when I ordered it. I saw the resistance was correct and ordered it.
Now, I would not recommend this, but I really don’t like how the knob fits, so I’ll just cut off a part of the shaft with my Dremel. It could damage the pot I suppose, vibration of the cutting disk, but I’ll be careful.
And finally, I’m ready for the next step: to finally solder the effect and complete the pedal. Looking good.