How To Make A Drill Guide Homemade Machines & Jigs
Or you can call this a portable drill press. I need this to drill some accurate holes in my new workbench, but could have used it for several projects I’ve done in the past. So I figure it’s worth the time to make and have on hand. And since this was made 100% from scrap wood (plywood mostly) I already had, it cost nothing.
The first step is to find the drilling axis of the particular drill you have and then mark that point on the end of the drill. I put a very straight rod in the chuck and then lined up strips of wood against it to extend an offset line to the end of the drill body:
This first operation tells you a lot: the offset required to clear the body of the drill to make it fit inside the carriage is very important. You don’t want to make the unit bigger than it needs to be or you will be less likely to use it.
I could then measure that offset:
And mark it on the end:
I also measured side to side and found the centre and marked that:
This is the drilling axis and you can use that to make the holder on the back of the to line it up properly.
Measuring the distance from the edges, it’s 1-1/2″ for one, and 1-1/8″ for the other on my drill:
This might sound complex and confusing, but you need to take it step by step and take note of the measurements. Making a sketch showing the distances and offsets helps to avoid confusion. As all drills are different, there’s no way to have a standard method to do this – you have to work it out on your own.
Not every drill has this side handle collar area at the front, but mine does and I’m going to use it. Measure with the calipers and then drill the hole:
That front collar is then fastened to the drill carriage backing plate. That’s made from 1/4″ plywood and sticks out 1/4″ on each side to fit in slots in the guide rails:
I can then start working on the more complex holder for the end of the drill. I measure the width:
Then transfer that to the filler that will go in the top:
Then measure what’s left:
And divide that by two and use that to make each side:
I made those side pieces from solid wood and then added another bar across the bottom to close it:
With the drill in the carriage and the rod back in the drill I confirmed that it was lined up correctly:
The guide rails are 3/4″ plywood and I cut 1/4″ square slots in the sides for the carriage to ride in. After it’s put together, you need to make sure it square and make any adjustments needed:
With the carriage put in:
The front bar swings up to remove the drill.
The base is more scrap plywood with a large cutout to clear the drill bit:
I used 2″ screws to fasten the base with the carriage in place:
Added non-slip pads to the base to help keep the guide from moving while drilling the hole:
And a counterbalance spring to offset the weight of the drill:
I didn’t have one the right size so I cut a longer one:
All finished and working beautifully:
I regret not making this earlier.
The build video: