How are jigsaw puzzles mass produced

[Phil Addison]

Thanks for that.

phil

PS How do you make the dies?

[Phil Addison]

Well, that much is obvious - we all know that you dont get wet in the rain if you run fast enough :-)

phil

[Phil Addison]

Oh dear, someone else not keeping up. It's "How do you make the dies?" now. How the dies are used was explained ages ago.

phil

[Phil Addison]

Mind you, a puzzle consisting of chopped up Jaguar sides could be interesting :-)

phil

[Andy Hall]

I'm not sure.

For some time, on and off, I've been building two model boats manufactured by a Danish company, Billing Boats,

the Wasa and the Calypso.

These have some components made from thin ply (about jigsaw thickness) and these are cut by laser- the information sheet says so and you can see the odd burn mark.

I suppose that their volume is not enormous - maybe hundreds per batch rather than thousands - but I guess that laser cutting is fast enough for this. Mind you, the sale price is a lot higher than a jigsaw, but I imagine that here they are trying to recover their design and tooling costs for the main design and small components.

.andy

To email, substitute .nospam with .gl

[Phil Addison]

Looks as if it will keep you busy for some time to come, too :-)

I wouldn't be surprised if they only cut them when ordered, stacking up a few extra layers to put into stock. NC tools are well suited to JIT techniques, but not low cost mass production.

There is a difference with jigsaw puzzles. Once you have the die you can cut not only 1000's of "Windsor Castle", but you can use the same die for many other puzzles. All you have to do is stick a different picture on the card before pressing it it through the cutting machine.

phil

[Ed Sirett]

Here how I think they _might_ be made:

Start with a long strip of quite thin metal of a tooling alloy that is hardenable but which starts in an annealed state. Say a metre or two long by 12mm by say 0.5mm (+? -?) thick. This is then bent plastically in to the loops and curves of one line of the jigsaw. I can envisage this being done on and around a variety of pegs and jigs and the like. I think this would be possible, there well might have to be some intermediate annealings.

The finished strip is then heat/chemically treated to harden and/or case harden. It is then welded/bonded to the die backing on edge along with all the other such pieces at suitable spacing.

The working edge is then ground parallel with the die back (rather than relying on the uniformity of the strip width) and finally with a lot of patience a cutting edge is ground onto the working edge. The later process being done with an air operated 'dremels' which have been around for a long time and a very small grinding wheel.

Two sets of dies are then needed to make a 'normal' jigsaw.

[Phil Addison]

Thanks Ed. At last we are getting to the meat of it.

Yes, that sounds eminently practical.

Could we start with a pre-sharpened strip, which is assembled onto your peg-board jig with the edge downwards onto a (softish) flat base? Perhaps 3 pegs would be used to form the strip around each 'lug' of the puzzle piece, which may randomly be male or female.

The strips would need to have slots cut in them at every piece junction to accommodate the perpendicular strips, which in turn need to have complimentary slots in them. These slots could be pre-cut before the strips are wrapped to shape. This would have the advantage that the cross-overs would be in slightly varying positions, according to how tight or loose the blades are woven round the lug pegs. This is desirable so that the sides of individual pieces vary in length. A fairly slack winding would give rise to variations in edge shape too, i.e. not all straight edged.

Yes, I imagine the cross-strips could be spot-welded to make a fairly rigid matrix. Some means is then needed to fix the matrix to a top-plate, which when the assembly is inverted, becomes the base.

To use this die, a puzzle card is placed on top, and the whole put through a 'mangle' press to progressively cut the puzzle. It's probably not necessary to have the whole blade edges flush in one plane - all that is needed is to put a scrap card onto of the job to ensure the lowest blade penetrates the job fully.

Thanks for your thoughtful solution.

phil

[Toby]

Probably the same way the ones used to cut stickers or transfers are made. You know the sort, rectangular carrier with the surface transfer layer, die cut around the outline of the action hero or whatever, but cleverly not cut all the way through the backing sheet. I'll ask my sticker designer source tomorrow.

[Gnube]

Do they need to work from hard water regions? ;O)

Take Care, Gnube {too thick for linux}

[Ed Sirett]

8-).

Turns out the URL we want is

says like you guessed that the strips have an edge before bending and fixing to the die backing.

One of the difficulties I could envisage is that hard tooling alloys tend to kink rather than bend smoothly. That is they have a large elastic stress limit which when exceeded is reduced substantially this means that all the plastic deformation happens in a localized place - or to put is simply it kinks.

The opposite is true of soft alloys - say like copper wire which hardens as it is worked and so is easy to bend into a smooth curve.

The web page also says that multiple dies can be used - this does seem _much_ less work than making an interlocked grid of strips. Although the interlocking method is also shown.

[The Natural Philosopher]

hats right. Lasers migfht take ten minutes to cut a puzzle - maybe more.

A die will do it in under a secnd propbably.

[The Natural Philosopher]

Possibly CNC milling. If you make the dies somewhat larger than the puzzles, you can stamp the puzzles with different parst to avopid the inevitable 'ooh. I recognise that shape. Its the one 27 down and 13 across from the top left' scenario that is the bane of serious puzzle addicts :-)

[The Natural Philosopher]

No..these are to be found in any scrapyard.

[The Natural Philosopher]

There is very little tooling cost on CNC controlled laser machine. You can do a design in e.g. autocad, run it through a software convertor, and that goes straight to the cutter stepper motors, which is a series of commands like 'move .03mm right and 0.05 mm up please'

It takes a day or so of wasted wood to get a batch going allegedly, then a few minutes per sheet. You can often cut several sheets at once.

Its ideal for short runs - in the hundreds.

If its thousands, die cutting is indicated.

[The Natural Philosopher]

ASctually if I were using that technique, I'd simply turn teh tool upside down, press a sheet of hard wood agisnt the cutting edges to ensure flatness, and flood teh die rear with molten metal to lock it all in place.

THEN I'd cut - not against a rigid steel plate, but against a scaricicial strip of cardboard, so that the die doesn't HAVE to be dead flat. You set it up to *just* clear teh machine bed, then shove your puzzle, on top of some scrap sheet, and cut aay. The scarp sheet gets binned.

[Phil Addison]

Yes, that could work.

Isn't that wot I sed??

phil

[Phil Addison]

Indeed. Someone mentioned annealing first, and hardening after, which seems like the answer.

And there was me thinking it meant something pervy :-)

It's also shown on the other link, puzzles.com or whatever it was.

I think I have a sufficient understanding now to satisfy my curiosity, so thanks to you all for the input, even those that missed the second key question. Hope you all enjoyed the challenge.

Over and out.

phil

[Andrew Vevers]

Thought I'd throw in an irrelevant comment on jigsaw puzzles. A bit back I got a 1920's jigsaw in a charity shop. it showed a picture of modern transport in London - cars, boats planes etc, and was printed paper on plywood.

I did the puzzle but there was one piece missing, so I was quite pleased when I found exactly the same puzzle in a flea market. I assumed that even if there were pieces missing I'd have enough to make up one good puzzle. When I did the second puzzle there were still bits missing but the pieces from the first puzzle appeared to be there.

It was then that I realised that the pieces of the two puzzles were completely different, and had probably been cut individually.

[Abdullah Eyles]

That's why I find it difficult to control stepper motors for my projects - I am forgetting to say "Please" to them (g)