Some questions for jigsaw puzzle makers

[oldjohnevans]

1) How do you cut jigsaw puzzles from a 32" X 32" board with a scroll saw with a 20" throat?

2) What is the standard jigsaw blade, both type and size, used to cut puzzles? I am sawing 3/8" Baltic Birch plywood.

3) How do you avoid "out of perpendicular" cuts, which make it impossible to separate the pieces?

4) Does anyone know how to paint pictures directly on Baltic plywood after the pieces have been cut. I want to be able to paint pictures on both sides of the board. I do not want the pieces to stick together.

5) If question 4) is possible what kind of finish can I apply to protect the painting, again without sticking the pieces together.

Thanks
John

ABCD goldfish - LMNO goldfish - OSAR goldfish

[Carter Johnson]

Wow, John. You've got some stumper questions. I don't know what kind of puzzles you are cutting, but I'll give your questions a try, with answers that I know won't satisfy you.

#1 - You can't. Either trim the board down in size or cut it in half somehow, realizing that you won't be able to swing it around as you do so. The size of the throat limits you and there's no real way around it.

#2 - I'm curious as to why you're using wood that's so thick. 1/4" is kind of the standard. Have you used 2/0 Superior Puzzle blades from Mike's Workshop? You may dull them quickly with 3/8" wood, in which case I would use a regular 2/0 blade.

#3 - If you use 1/4" you won't have the bevelling problem. In any event, increase the saw's tension and speed - and go slower! The old adage: Let the Saw Do The Work applies here.

#4 - I can't imagine painting a picture AFTER you've cut the pieces. Why? You're bound to drip between pieces, which wouldn't look good. Just paint pictures on both sides and then cut. Why reverse them?

#5 - I know of no finish that can be applied, sprayed or brushed, after you've cut the pieces that would protect the puzzle and keep the pieces from a little sticking to each other, unless perhaps you sprayed each piece individually. Again, why?

I'm sorry I haven't been much help, but I'm hampered by not knowing what you want to accomplish.

Carter

[jigsue]

I always spray the varnish AFTER I have cut the puzzles and they do not stick. I use acrylic spray varnish (3M, Krylon or whatever I can get hold of at a reasonable price), but I agree with Carter on the painting, your must do this BEFORE cutting. If you are worried about fuzzies or breakout, put a piece of rubbish ply, MDF or even hardboard at the top and bottom, this will certainly minimise that.

Your throat totally determines the size of piece you can cut, although spiral blades allow you to cut bigger, although I think even the smallest spiral will provide too big a kerf for puzzles.

Please give us an idea of what you are trying to do and they, perhaps, we can be of more assitance.

Sue

[oldjohnevans]

Thank you for your prompt responses. 1) My questions are all based on cutting shape shifting puzzles. (as described before) 2) I like the feel of 3/8" plywood. I am motivated by artistic preference, not financial necessity. 3) I have to paint the pictures, top and bottom, after the pieces are cut. This is because the puzzle will be in a different shape when the top and bottom pictures are painted. This adds to the interest and challenge of the puzzle. I will find a way because I am very good at solving technical problems. 4)Thanks for the tip about the spray varnish. 5) in retrospect I realize that my out of perpendicular cuts were due to my practice of moving around the saw as I cut. Now I stand quite still in front of the saw and constantly reposition my hands on the wooden panel. When I take pressure off the wood the saw blade pulls it back into alignment. With a little care I am learning to make complicated and perpendicular cuts on 3/4' plywood.

[Tor]

In a 3/8" thick puzzle, you might get away with a 2/0 spiral blade. It would come out loose, and if you could get at a saw where you could cut it in half with a flat blade of your chosen size, you would do better that way. Cut the entire puzzle with the same blade (size, not piece of metal), or you will end up with something ugly.

According to my calculations, you need an absolute minimum 22 5/8" throat to cut to the centre of your specified size and be able to swing it properly. If you can find a 24" (or better) saw, and wish to do this, you will need to cut from edge to centre, stop the saw, remove the blade (do not try backing out of the cut. It will be too much work), and reload to come in from the other side. Cut the halves into quarters while you have the 24" saw for convenience.

Tor

[jigsue]

You could paint the pattern on one side prior to cutting, that would save some time and effort, then on side two if it were something slightly more abstract, it is reasonably easy to paint each individual piece of the other side. I paint individual pieces in some of my jigsaws.

Sue

[fallingacorn]

i usually spray some coat on after i finish, even a couple, maybe if you sprayed or dunked each piece individually you might fill in space if you are stuck using a 2/0 spiral to take off sections that you could use in your throat capacity. i noticed the noodle style cuts you were using, or maybe i'm confused and it was someone else (if so that might be something to look at), on previous posts might be the idea for taking down the puzzle one section at a time with a spiral.
good luck

[Tor]

Originally Posted by Falling Acorn

on previous posts might be the idea for taking down the puzzle one section at a time with a spiral.

Sorry mate, but I personally feel that mixing blades in a puzzle is not ideal. An experienced puzzler will very quickly pick up on the differences in cut to get an idea of where to place the piece.

I also must admit to forgetting puzzle cutting when I suggested a 24" throat. The correct minimum should be 35 3/4", diagonal of a 16x32 rectangle, not 22 5/8", diagonal of 16x16 rectangle.

Tor

[iohonnes]

Originally Posted by oldjohnevans

1) How do you cut jigsaw puzzles from a 32" X 32" board with a scroll saw with a 20" throat?

2) What is the standard jigsaw blade, both type and size, used to cut puzzles? I am sawing 3/8" Baltic Birch plywood.

1) I put together a spreadsheet to help me determine how big a puzzle I could cut with my scroll saw. I generalized it so that throat depth was an input. I normally think of cutting a puzzle by starting at a corner and working piece by piece until I'm finished. Using that method, I'm limited by the diagonal length of the puzzle. But if I started cutting in the middle of the long side, I could work down the center-line of the puzzle, effectively dividing the puzzle into two halves, but also changing what the effective "diagonal" length was. I also allowed for a work area, which I called a "gutter" on the spreadsheet about the center-line. I have diagrams in the spreadsheet if you take a look.

It appears that I can't attach an excel file directly, so I zipped it first.

2) I use the Flying Dutchman special puzzle blade from Mike's Workshop. But I wouldn't say that there's a standard. In general, the thinner the blade, the tighter fitting. But you may not always want a super tight fitting puzzle - for example, older or younger puzzlers may have a better experience with a slightly looser puzzle. My 5 year old daughter likes to pound in pieces (with her little balled fist) on my puzzles - she has hard time getting the pieces to line up just right, so out comes the hammer! Some folks also use Jeweler's blades (I know that Carter uses them for specific applications), but from everything I've seen and read, they are not as suitable for larger puzzles. They just aren't designed to cut that much wood.

John

[Tor]

Nice spreadsheet. I created a function in my calculator such that I can input two numbers, and it will tell me the diagonal, but yours is nice and easy.

Tor