Thread: Impossible puzzle

I dont really care about the answer but could we all chip in and buy him a bl**dy squre.

Originally Posted by squashedfrog1

I have no solution.

But for whoever it was that mentioned it earlier looking for cheap xmas presents......have a look at this site.

http://www.frik-n-frak.com/Dovetail-..._101-1910.html

The rubber band puzzle would be perfect for a wood turner. And no. I don't want one for xmas.

No more puzzles.

sf

That was me, but I don't have a lathe, so I suppose I'll just tackle one of these simple looking puzzle boxes.

No problems.

It looks like all have well exercised their melons over this one. Use it or lose it, as they say.

I suppose I could say I figured it out by myself, but that's not my game. No, I heeded the old NASA maxim, "Search before research." I prowled the weird wild web, and found several discussions of this conundrum; none of them quite as imaginative as the thread on this forum. Only one hit was authoritative, though; attributed to Roy Underhill: "The method to this puzzle was explained this weekend {Post was 29 Aug 2005} on the pbs show the woodwright shop. The block is cut out of (I believe he said bass wood?) and the last tooth is placed in boiling water for ten minutes. It is then immediately put in a vice and compressed, and left in this position for two days till dry. When removed from the vice you drill the hole and insert the nail in the two middle teeth. {Must have been the four-tooth version} Then return the block to boiling water and it will return to its original shape." {comments added by me} I'm calling this the Roy Underhill method, although there are several folks making and selling the thing. My experiment pictures are attached.

Pic 1: Boil for 10 minutes. The duct tape guy straps keep the block from falling over.

Pic 2: Squeeze in a vise. Note severe distortion of the tooth.

Pic 3: Drill the second tooth. I waited only one day; this was sufficient for my timber. My drilling was slightly tilted. Normally, I'm more accurate than this. I attribute the shortcoming to the enthusiasm of the chase.

Pic 4: Insert pencil.

Result, as well as discussion and my suggested improvement, in my next post.

Joe

Continuation:

Naturally, I'm calling this next one the Joe Greiner method, until it's declared non-original.

To avoid the one- or two-day wait, I added a follower block at the outboard tip of the tooth. I also added a cushion block at the other end; these would avoid impressions created by the vise jaws. Unfortunately, the combination now exceeded my vise's capacity. So I used a pipe clamp instead. (Pic 1). Because of reduced leverage, I had to use a pipe wrench to close the jaws; luckily, I didn't destroy the clamp. A larger-capacity bench vise would obviously be better. Note again the severe distortion of the tooth. Note also the grain direction of the follower block; don't need any compression of it.

Pic 2: I drilled through the follower block into the second tooth.

Pic 3: Inserted the pencil through the follower block into the second tooth.

After removal from the clamp, there was only limited recovery; re-boiling still necessary.

Pic 4: Final results of both samples. These were after less than five minutes' re-boiling. The second one didn't even reach boiling.

Observations:
1. The wood should have widely spaced growth rings, to maximize the compressible region.
2. The timber should be aligned with a radius of the tree, to minimize distortion. (Pic 5) I culled the stack at the Borg, and selected a timber which best satisfied this requirement. I expect it would have worked better if I had run the board through a jointer or thickness planer to enhance symmetry. This one is 2x4 unkwood, probably Southern Yellow Pine (Actually 1.5" x 3.5", or 40mm x 90mm).
3. Assuming planing for symmetry, I could also have reduced the scale, as well as the thickness of the follower block. Along with use of a thinner cushion block (such as a sheet of Ally), it might then fit within the vise jaws. Still need the follower block to be thick enough for drilling.
4. The nail works the same as the pencil. For the threaded rod with a nut, the easiest way to insert it is likely to use a coupler nut and another piece of rod chucked in a drill; otherwise quite tedious.
5. Have a look at Carry Pine's post #13. Boink the first thumbnail, and print the picture. Scribe a vertical line along the tips of the two lower teeth, to the top of the puzzle. The top tooth is about a mm or two shy. My samples exhibit the same phenomenon.

The search I mentioned in my previous post also disclosed a reference to the books "Wonders in Wood" and "Puzzles in Wood," both by E.M. Wyatt. I think I have one of them, but if so it's still in a moving box.

The "rules" said no steaming. But didn't say no boiling. Splitting hairs perhaps, but distractions like this are the basis of most magic tricks; that's why most magicians have a scantily-clad assistant.

I hope this doesn't seriously detract from the mystique. It's still somewhat tricky to execute.

Joe

Your a clever fella Joe. Thanks for the discription.

I had no idea timber could be compressed like that after boiling.

Have you put any thought into the impossible dovetail ? ...another thread thats being going on here....been pulling my hair out over that one.

Jake, I was amazed at the compressibility myself. Kept on a-crankin' and it kept on a-squishin'.

Scooter's post on the impossible dovetail (post #4 of that thread) sort of made sense, so I didn't chase it any further. I'm not much of a darksider, except for a little hand planing, and I haven't done any dovetails at all. The impossible dovetail puzzle (Brendan's post #76 on this page) has been around a long time; don't remember where I first saw it.

Thanks for your comment.

Joe

Sorry I have not been following the thread.

Can you bend the nail?

Or am I crazy?

Ignore what I just said.

It looks impossible to drill the hole in the middle. Unless you can bend the drill bit.

Sorry

Originally Posted by joe greiner

Scooter's post on the impossible dovetail (post #4 of that thread) sort of made sense, so I didn't chase it any further. I'm not much of a darksider, except for a little hand planing, and I haven't done any dovetails at all. The impossible dovetail puzzle (Brendan's post #76 on this page) has been around a long time; don't remember where I first saw it.

Egads! I've tried compressing wood before (the old arrow thru a glass bowl trick) but hadn't even thought of it in this context... and it could also be applied to the impossible dovetail!

Cut the dovetails slightly oversize for the mortises, then boil/compress the dovetail end so they'll slip straight into the mortises and boil again Hmmm... would need an offcut inserted between the dovetails to keep the slot clear; that could be awkward. [ponders]

You'd need a BIG pot to make a chair that way ...but what a conversation piece!

Guys!

didnt Felder just give us the answer to the impossible dovetail? First post on this page?
I tell you, I'm sleeping easier!


sf

Originally Posted by squashedfrog1

Guys!

didnt Felder just give us the answer to the impossible dovetail? First post on this page?
I tell you, I'm sleeping easier!


sf

Not quite.....

I gave you a link to the answer that was supplied by Custos for a different impossible dovetail - the one that you showed a link to on another site. So you can rest easy on that one.

Now before you get all rested and stuff, see if you can work out how the nail got in the middle of the "E" thingy that Carry Pine bought.

And if that doesn't keep you up, see if you can work out this impossible dovetail.

Originally Posted by Felder

Not quite.....

Now before you get all rested and stuff, see if you can work out how the nail got in the middle of the "E" thingy that Carry Pine bought.

Check out the page previous to this. Think Joe's got the answer. Good pictures too. It seems to be the most likely solution to me.

Originally Posted by Felder

And if that doesn't keep you up, see if you can work out this impossible dovetail.

Thaaaaaats the one I want the answer to. Don't think Lignum and Zenwood used boiled water though......say nothing like that....just your everyday magic apparently.

AAAAAAAARRRRGGGGGHHHH!

Originally Posted by squashedfrog1

AAAAAAAARRRRGGGGGHHHH!

whats wrong ? ....you having some kind of fit ?