Sunday, June 22, 2014

More Fun with Fairham

Needing a quick gift for a good friend's 40th birthday party, I pulled out my trusty copy of William Fairham's Woodwork Joints, and found a quick project that looked both fun to build, and fun to use:  the Chinese Puzzle.
Fairham's Chinese Puzzle
"No problem, I should be able to knock this out in a couple hours after work," I thought.

I find that it is really difficult for me to estimate the time required for a project, if I haven't made that project before.  I wound up spending about six hours total on this project. 

I never said I was fast enough to make a living at this.

Decisions, decisions.
The first order of business was to find appropriate stock.  Fairham says to use 1/2" square stock for this project. 

I find that when making puzzles, it is a good idea to stick to the directions exactly for the first time, so an understanding of the puzzles function becomes clear before one starts messing around with the dimensions.

I have quite a bit of stock that would be OK for this project.  However, the pear, walnut and oak I had was all just a smidge too thin.  It was at this time that I remembered that I have actually started this project once before, and already dimensioned some maple (Acer platanoides, I think).  

I abandoned this project before because it appears I crossed my layout line while ripping on one of the sticks.  Lets charge ahead anyway, as I think that there is enough without that one.  One of the other sticks appears that I dimensioned three sides, and left one for later.

My first step is to plane this last side down to my mark.  I find that with small parts it can be easier clamping the plane in the vice and moving the small parts over the plane.
Thicknessing small parts.
Using a cutting gauge is nice for precise jointing, as it is obvious when final thickness is reached.  As in the photo below, a little strip comes up to let us know we're there.
In this case, there is a little more to go on one side before I'm done.
After the stock is prepped, all 21 pieces can be cut to length.  I do this on my shooting board,
Cross cutting parts to length.
because I can shoot the ends without changing the set-up on my bench.
All parts are now perfectly the same length.
It doesn't take too long before I am done, and realize I am still short quite a few of the needed 21 pieces.  I need some more 1/2" stock!
This bit of 3/4" maple will have to do.
So much for being smart. 
Ripping a 1/2" strip off of my scrap.
This wound up slowing me down.  Dimensioning this stock is not difficult, but you must take your time to do it right.  All of the puzzles pieces must be as perfectly the same as possible in order that the puzzle will go together and come apart again.
Finally.  Let's start cutting the notches.
Once all of the parts are dimensioned and cut to length, the notches for the puzzle can be made.  I marked the notches out with my cutting gauge, sawed to the line and chopped out the waste with a 3/8" chisel.

Now that the party is coming up fast, I need to hurry.  I'm afraid to say that the inside of my notches look pretty rough.  With a little care, the insides should look pretty, because the recipient will spend some time looking at them trying to figure out how the puzzle goes together.

Too late for this one, though.  At least it should look nice once it goes together.
Finally, all the parts are done.
One quick word about what makes this puzzle work, is a small piece called the "key."  This one has a notch on two sides, and the inside is rounded over a bit.

This piece took me quite a bit of fiddling, as not enough material was originally taken out of the inside corner to allow the key to work properly.  Take some time with this step, or the puzzle simply will never go together.  Not a result you should strive for.
The key.
Once all of the pieces were tested and fit, I put a tiny chamfer on all of the sharp edges to make it a bit more comfortable to hold, and finished it with a homemade furniture polish concoction made of beeswax and orange oil.
My Chinese puzzle.
My good friend seemed to enjoy the puzzle.  He spent a little time and put it together three times in a row!  
Gary is thinking.
  • Construction of this project took a little longer than I thought it would.  This is normal for me.  I am confident, however, that next time should go faster.  
  • Now that I understand how the puzzle functions, I can adjust the dimensions of the puzzle to make bigger and smaller versions.  It was good to stick to the plan for my first try, as without a full understanding of the functions of the different parts, this first prototype worked correctly.
  • I think the notches I cut were a bit too accurate.  A little slop in some of the joinery might make the pieces slide a bit easier.  As it is, a few of the pieces need to be forced into the right place where the fit is tight, and the key on this one turns with only great difficulty.  Especially when disassembling.  Some looser tolerances should help things.  I went for a nice friction fit such as you would want on a dovetail joint, when what is really needed is a fit that allows the pieces to drop together without force.
  • When you give a gift to someone with kids, a bag that plays "Bad to the Bone" is an awesome distraction.
  • I think next time rather than cutting all of the pieces out, and then making the notches, I will run a dado on a wide 1/2" board, and then rip the pieces.  This should be faster, neater, and more accurate.  Gang cutting six pieces at once sped things up a bit, but there is a danger the cutouts won't all be exactly the same.
  • This is a perfect project to make with only tools from my Beginner's Tool Kit - I used a BU jack plane, a marking gauge, a Ryoba saw and a 3/8" chisel.  I also used a 5pt. rip saw for ripping, a dovetail saw for cutting notches, and a 1/4" chisel for one piece that has an especially narrow notch.  I think that these extra tools are optional, and evrything could be done without them.
This is the second puzzle I have made from Fairham's book.  If you would like to see the first, see this post.
Diagonal Chinese Crosses - my First Fairham puzzles.

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