I'm building some cabinets for a client at the moment and needed to drill a series of 5mm holes for bookshelf pins. You can buy all kinds of jigs that do this, but with a couple of scraps of wood, a couple of very basic tools, and a pair of 5mm drill bits, you can make your own pretty easily.
I could have just marked out a couple of hundred pencil lines and started drilling, but for the shelves to sit perfectly flat the holes need to be perfect, and I also think that the time saved more than covers the time to make the jig (and probably the second one I made to photograph for here, and the time to sit down and write this guide....)
To get the spacing identical on every single hole, I made a jig, which I used to make a bigger jig, which I used to do the job.
Step 1: Gather Materials
Some of these are optional, others are not, but to give you an idea of what you are likely to need...
- Wood to make the jig from. I used scraps of 18mm MDF.
- Two 5mm drill bits (or whatever diameter your shelf brackets are. Most in the UK are 5mm)
- A drill
- Double sided tape
- Obvious things like pencil and ruler
Step 2: Making the First Jig
The basic rule is that for these to work, we need all the holes the same distance from each other, although what that distance is makes no difference at all. This is why I decided to go for a jig to make a jig. You could measure out 10 holes on one piece and drill them out, but if the spacing between a couple is off by half a mm, it adds up over the length.
First up, find a small piece of scrap, big enough for two holes. I cut an offcut of MDF down to about 100mm long, although this measurement doesn't matter at all. Draw a line on this piece, and put two marks on the line, however far apart you want them. Punch and drill these two holes with a 5mm bit.
The second 5mm drill bit is being used as a register pin. This means that the spacing is always the same between holes. To do this just stick a 5mm bit through the hole, blunt end first. The friction should hold it firmly in place.
This is the jig that we'll use to make the jig.
Step 3: Making the Second Jig
First off I added a guide using another scrap (with a known good edge) and some double-sided tape. You could screw this down or use hot glue - the plan is to pull it off later on anyway.
Truthfully, that was attempt number two. I did attempt drawing a line to reference the jig off, but it wasn't accurate enough. It's worth spending the time getting the jig right now, rather than having 200 incorrectly drilled holes. Hence sticking down a temporary guide.
Decide where the first hole in the jig should be. Keep the holes over to one side of the piece so you have enough room to set the distance between the edge of your work and the holes. Drill the hole with a 5mm bit, going all the way through.
Now take the first jig, and put the blunt end of the drill bit into the hole you've just drilled, and the edge of the jig against the guide. Pop the drill into the second hole, and drill through. Lift up the jig, register it off the hole you've just drilled, and continue.... pretty much until your second jig has run out of space. I think I got about 8 holes on my big jig.
The last step is to pull off the temporary guide from step one, and measure out and attach a permanent guide that will register off the edge of your workpiece. I wanted my holes inset by 50mm with this jig, so I measured 50mm across from the hole at each end of the jig, and used these marks to attach a guide to the MDF. You can use screws, or double sided tape, or anything else that will hold it in place.
Step 4: Drill to Your Hearts Content
We're good to go! Mark out vertical position of the first hole (remember a shelf will have 4 pins supporting it, and they all need to start from the same height). This first hole needs to be drilled without the jig, and only needs to be about 5 - 8mm deep. Then use the drill bit to register the jig to hole number one, clamp the opposite end, and simply drill the remaining holes. Then move it along, drill another bunch. It's kind of like an exciting game, except it's tedious, boring, isn't actually exciting, or even mildly fun.