Drilling Shelf Pin Holes without a jig and without measuring
I needed to build a small medicine chest for my rental house and I didn't want to spend a lot on it so it was getting built with melamine coated particle board. I wanted to dress it up a bit so I added some pine banding to the edges. Admittedly lipstick on a pig but still better than a pig with no lipstick. I wanted it to be versatile so I wanted to add shelf pins so that the shelves could be adjusted since I had no idea what would be going in it. While contemplating this I had an idea how to do it without using a measuring tape or ruler even once by using just a drill press, a stop, some spacers, and some clamps. It turned out to be a very simple method. The #1 photo shows a regrettably blurry image of the finished chest with one moveable shelf on the left and two on the right.
Starting the build
I needed an extended table on my drill press so that I could clamp stops on the left and right sides of the drill bit to space the holes and locate them. I also needed a fence to control the distance from the edges to the pin locations. I grabbed a left over piece of sub floor OSB that I thought would be adequate. It turned out to be barely so. I would up having to angle it and it was only barely long enough even then. Maybe the one thing I should have measured.
I realized that shelf pin holes could be drilled with just using a drill press, a fence, stops, and spacers as I said. The fence would be clamped in relation to the drill bit to control the distance from the edges inward to the pin holes. A stop would be located to start the first pin hole and spacers would be used to control the spacing between pin holes. Each setup drills one column of holes in one side and the mirror image on the other side. I started with the front column of holes in the left gable so the same stop is the setup for the rear column of holes in the center divider. Once the stop was set I put a reference stick against it and drilled a hole in it (photo 2). This is the key to being able to duplicate the distance from a stop on the left side to a stop on the right side to accurately drill the other two columns of holes. I used a brad point bit and it worked but a Forstner is a better idea for this.
Locating the first stop
I wanted the pin holes on the left side of the cabinet where there would only be one shelf to start just below center and go a bit above center. How much either way was immaterial without knowing precisely what would be going in the cabinet. So measuring it wasn't imortant. The stops were set for the lowest hole and spacers were used to space the holes apart from there. Standard hole spacing in Euro style cabinets is 32mm/ 1.25" but this is a small cabinet at 20" high by 30" wide so I thought that a little closer might offer better versatility so I set my table saw for 1" and ripped a strip off some mdf for the spacers. This is as close as I came to using a measure as the rule on my Unisaw is very accurate. With the stop and fence set in place I started drilling pin holes (photos 3 and 4).
Drilling the first column of holes in the Center Divider
The center divider just sits on top of the bottom plate of the chest but the gable is flush with the bottom of the chest so that requires an extra spacer to keep the holes level. Since the divider just sits on the bottom plate a piece of the bottom plate material is all I needed to use. Had I dadoed a groove in the bottom plate for it then I would have also needed to dado the extra spacer. The remaining holes were drilled with the same spacers as before (photos 5 and 6).
Using the Reference Stick to set the Right Stop
To set the right stop for the remaining two columns of holes I flipped the reference stick over 180 degrees and lowered the drill biy into it. With the drill bit holding the refence stick in place I moved a stop against it and clamped it to the table (photo7). These two columns of holes were drilled exactly the same way as the first pair.
Setting up for the Right side of the Chest
The right side has different spacing than the left side. I wanted two shelves in this side for smaller objects so the bottom shelf would be lower and the top shelf would be higher than the shelf on the left side of the chest. Consequently I needed new refernce holes in the reference stick. In photo 8 it shows me drilling the new hole. Because I had the depth stop on the drill press set for the blind pin holes I lifted the reference stick up so I could drill through it. I realized after that I didn't really need to do that. The blind hole would have worked just as well. Photos 9 and 10 show the bottom holes being drilled and the center divider still required the extra spacer. By this time I realized also that my original reference stick wasn't long enough to register the stop for the top sets of holes so I grabbed another stick and drilled it. Photo 11 shows all the holes and both reference sticks drilled for the right side of the chest.
I've tried a few ways to drill pin holes and this was the simplest and most accurate. I did get two holes off level on the right side and they were diagonal to each other and off by exactly the same amount which means they were part of the same setup so that means I wasn't paying enough attention and got something out of place. They were the middle holes on the bottom sheld and the holes above them were dead level so I'm not sure what I did wrong but I corrected it without realizing I had done it. If you do get any pin holes off then I would just glue a shim on the lowest pins to make up the difference. No one is likely to notice not that I would send that out if it was a paying job. Because this method is so simple it is also very fast. This took about 2 hours and a part of that was taking pictures. This is a small chest but it could be scaled up some using the same method. However, there is a practical limit because you have to work the same distance in both directions from the drill bit. A 4 foot gable would require up to an 8 foot table on the drill press and maybe support legs to keep it from getting tippy.
Trying to measure all the pin holes and then drill them is guaranteed to produce poor results. The lack of measuring this way is more likely to produce good results. I was taught years ago that if you can directly transfer a dimension from one piece to another then that is the best way to do it. This was proof once again that that is true. Although this was technically jigging up for the job, no jig as we usually refer to one was built so there was time saved by not doing that. Past the practical length for using this method it would be necessary to build one.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.
Last edited by Cherryville Chuck; 11-23-2016 at 11:37 AM.