Hello -

I would love to make a "flip card" (or slate) which appears to be two sided (a front and a back) but can display five to seven images in fairly rapid succession - as in, there's a picture of a nest, flip it over and you see an egg, flip it again and now there's a bird, flip it again and there's a tree....you get the picture.

11" x 14" or so in size, with a decent (thin) profile.

I'm just stumped on how to research technique...any leads or advice would be appreciated...I can't make a decent model of it, and I feel certain that this would be a fairly old idea - but I just don't know where to look (as I don't know the proper name for such a device)

Help??

amanda

Hi Amanda,

The flaps must be very thin, so there is very little bulk at the hinge points. They should also be staggered for the same reason. Tape hinges would be ideal, as long as they don't interfere with printing or painting your images.

It would also be beneficial if the hinges were applied such that the two parts being joined are slightly separated with flexible hinge (cloth of tape) between them. When the first flap is thrown, it doubles the thickness of the area now covered by the flap. So the next flap must be designed that it can step up to that level, and then lay flat on top of the previous flap(s).

Think of the flaps and the flexible section of hinge as a very thin book's cover. The flexible section of the hinge serves the same purpose as the spine of a book. Coming from the rear of the book, the spine must step up the thickness of the pages before it can fold flat against the front. These flaps do the same thing in miniature. I can visualize what is very hard to put into words. Frustrating...

For five changes, you'd need 1 flap on one side (shows 2 images), and 2 flaps on the other side (to show 3 images). No "step up" section of flexible hinge would be needed on the side with only one flap.

For six changes you'd need 2 flaps on each side, and for seven changes you'd need 2 flaps on one side and 3 flaps on the other side.

The images would have to be small enough on the flaps that part of previous or next images won't show at the staggered edges.

By staggered, I mean the next hinge should be attached to the board, approximately 1/8" - 1/4" away from the previous hinge. Otherwise, things would bind.

Hope this helps.

~michael

Michael, thank you! Your advice is clear and cogent. I will possibly bug you again if I can't quite manage it, but I have started on the mock-up, and all seems to be going well.

Do you (or does anyone) know the proper "name" for this?

Again, thanks -
amanda

Hi Amanda,

I can't recall seeing multiple flap versions, but there have been a couple with single flaps (or single flaps on both sides). I think any name attached to them would be consistent with the trick it created. Probably just called a flap card, it can probably be found in books as early as Hoffman, although I don't have them out to get to right at the moment. With a card, it may be a Hofzinser creation, but again, the books I need to search are kind of buried at the moment.

I also have a version that causes 45 rpm records to change color. I've seen it with cards, pictures, signs, bills, slates, and to a certain degree, even with coins. Same idea, and I'm sure it has been applied to a thousand different tricks over the years.

~michael