How not to do a wooden hinge
I recently posted a project of a box with a wooden hinge where I said "I wouldn't do it the same way again". The best way to explain why is to explain how I did it. Yes, I know there are a lot of other ways of doing this, but I did it this way regardless - call it an experiment if you like.
I made my box in a workshop that is part of the local education system. One of the odd constraints that put on me is that I was not allowed to use the table saw - the person in charge cut my wood to width, but that was it. Instead, my challenge was to use the router. The thing is, I was initially unsure what bits would be available so I designed everything to use a rebate bit, and not to use a cove bit for the hinge recess as I should have. That gave me corners in my recess requiring a teardrop shaped hinge with a corner to go into the recess. I didn't take a decent photo, so there is a sketch below (together and exploded).
To make the hinge pieces, I started with a 12 mm x 12 mm square length of wood (12 mm = 1/2 "). I routered a rebate into a scrap piece of timber and strapped my wood into this, then used a router with a roundover bit having a bearing tip. I did one corner, rotated the wood, did the second, rotated again and did the third.
Once it was shaped, I cut the hinge segments and marked centre for drilling. This is probably where I went the most wrong because to get centre, I put each segment into a rebate 6mm (1/4") deep and used a ruler across the surface to draw one line, then rotated the segment in the rebate before marking the second line.
While this method is perfect in theory, it is perhaps not so in execution. It means that I marked relative to the point rather than to the curve. I should perhaps have used either a hermaphrodite caliper or a centre marking tool such as that which I have sketched up below.
Next, I made up a simple and very rough-and-ready jig to hold the segments in place on the drill press, and I drilled right through three segments and into, but not right through, the end two.
Next came the rebate in the box. I was able to hold base and lid together in the vise with another long piece of wood for the router fence to run along. Note the G-clamps used to limit the length of the router cut that could be made. The rebate was made by plunge routing using, as said before, a 12 mm rebate bit.
You can see the resultant rebate below with the hinge just sitting on the box. By this time, the ends of the hinge have also been rounded to suit the rebate.
All that is left is assembly. First I glued the assembled hinge into the base.
Then I glued the top to the appropriate hinge segments. Now this is a big reason why I might not make the hinge this way again. You can see that I do not have the top glued into the lid frame. This came about by accident, but proved to be a blessing because even without the top in place, applying suitable pressure between the hinge and the lid frame was tricky. In fact, the photo below is my second attempt because the first attempt failed.
So, Lessons learned:
1. My hole through the centre of the hinge was not accurate enough - I had to use a drill a fair bit larger than my brass rod to get the all the segments to go together.
2. I was initially worried that I would notbe able to hold round dowel firmly enough in the drilling jig to stop it from spinning when drilled. I now think that was an unnecessary concern.
3. The glue-up was really tricky. Of course, it would have been simpler if I'd left the brass rod out of the hinge until all the bits had been glued into their respective parts of the box. Yes, I'd have had a hole to fill, but it is end grain and unlikely to be noticed (or could even be turned into a feature). However, that really only works if the hinge runs the full length of the box. Because mine is shorter, the edge of the rebate gets in the way so I didn't think it would go in well.
4. I had to make my hinge shorter than the length of the box because I used a rebate bit rather than a cove bit - the rebate would have been visible with a full length hinge and I didn't want that.
So that's it. Next time I'll do it one of the ways other on LJs have suggested.
I recently posted a project of a box with a wooden hinge where I said "I wouldn't do it the same way again". The best way to explain why is to explain how I did it. Yes, I know there are a lot of other ways of doing this, but I did it this way regardless - call it an experiment if you like.
I made my box in a workshop that is part of the local education system. One of the odd constraints that put on me is that I was not allowed to use the table saw - the person in charge cut my wood to width, but that was it. Instead, my challenge was to use the router. The thing is, I was initially unsure what bits would be available so I designed everything to use a rebate bit, and not to use a cove bit for the hinge recess as I should have. That gave me corners in my recess requiring a teardrop shaped hinge with a corner to go into the recess. I didn't take a decent photo, so there is a sketch below (together and exploded).
To make the hinge pieces, I started with a 12 mm x 12 mm square length of wood (12 mm = 1/2 "). I routered a rebate into a scrap piece of timber and strapped my wood into this, then used a router with a roundover bit having a bearing tip. I did one corner, rotated the wood, did the second, rotated again and did the third.
Once it was shaped, I cut the hinge segments and marked centre for drilling. This is probably where I went the most wrong because to get centre, I put each segment into a rebate 6mm (1/4") deep and used a ruler across the surface to draw one line, then rotated the segment in the rebate before marking the second line.
While this method is perfect in theory, it is perhaps not so in execution. It means that I marked relative to the point rather than to the curve. I should perhaps have used either a hermaphrodite caliper or a centre marking tool such as that which I have sketched up below.
Next, I made up a simple and very rough-and-ready jig to hold the segments in place on the drill press, and I drilled right through three segments and into, but not right through, the end two.
Next came the rebate in the box. I was able to hold base and lid together in the vise with another long piece of wood for the router fence to run along. Note the G-clamps used to limit the length of the router cut that could be made. The rebate was made by plunge routing using, as said before, a 12 mm rebate bit.
You can see the resultant rebate below with the hinge just sitting on the box. By this time, the ends of the hinge have also been rounded to suit the rebate.
All that is left is assembly. First I glued the assembled hinge into the base.
Then I glued the top to the appropriate hinge segments. Now this is a big reason why I might not make the hinge this way again. You can see that I do not have the top glued into the lid frame. This came about by accident, but proved to be a blessing because even without the top in place, applying suitable pressure between the hinge and the lid frame was tricky. In fact, the photo below is my second attempt because the first attempt failed.
So, Lessons learned:
1. My hole through the centre of the hinge was not accurate enough - I had to use a drill a fair bit larger than my brass rod to get the all the segments to go together.
2. I was initially worried that I would notbe able to hold round dowel firmly enough in the drilling jig to stop it from spinning when drilled. I now think that was an unnecessary concern.
3. The glue-up was really tricky. Of course, it would have been simpler if I'd left the brass rod out of the hinge until all the bits had been glued into their respective parts of the box. Yes, I'd have had a hole to fill, but it is end grain and unlikely to be noticed (or could even be turned into a feature). However, that really only works if the hinge runs the full length of the box. Because mine is shorter, the edge of the rebate gets in the way so I didn't think it would go in well.
4. I had to make my hinge shorter than the length of the box because I used a rebate bit rather than a cove bit - the rebate would have been visible with a full length hinge and I didn't want that.
So that's it. Next time I'll do it one of the ways other on LJs have suggested.