Hi All,

I am trying to build a set of Multum In Parvo glasses, here is a picture of a prototype:

http://www.dreamfactory.com/magic/multum_parvo.jpg

These acrylic tumblers look great and have the right pattern to be very deceptive. I want to make the version of the trick where you could pour from the biggest one down to the littlest one. I like this method, it is easy for setup, very flexible, and there are no vibration problems to give away the secret like the other method.

HOWEVER I am having some major engineering problems getting this done!

First, the acrylic interiors I have constructed LEAK. No, really. I am using the best acrylic glue etc. The joints leak, but because the bottom of the glasses are a dome shape the bottoms really leak...

Second, I am having trouble getting the displacement just right. I want the tops flush, but the interior circumference is currently either 1.5, 2, or 2.25 inches. I need a way to make adjustments...

Lastly, is there a better method entirely to do this? What about solid acrylic vertical bars, or something like that? It needs a good appearance from the top if possible as well... The pour-ability is important. You want to be able to quickly pour from glass to glass. An entirely solid top with some room around the edge works better than you might expect due to surface tension....

Do you guys have any suggestions?

Thanks!

Glue is never used on acrylic. Sometimes Silicone can be used depending on the application. I always weld plastic together by heat or solvent.

The displacement problem has everything to do with the use of standard diameter tube/glasses,

You can add a clear rod on the back side of the gimmick to take-up volume.

You can use a lathe to make the tube exact then polish it,

You can change the method so each of the glasses has a partition like a M glass.

You can cheat the amount you pour by allowing some to go in the tube.

You can cheat the amount you get out, by starting with some in the tube and hiding the bottom.

You can put a paint stripe around the bottom of each glass and the ones that need less volume have an insert, in the bottom.

You can look around for other glass/tube combos that "do the trick"

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This is a good exercise to see how many other ideas people have.

Go

Great post Jay

one thing I am realizing is that the taper of the glass is a real issue. any gimmick probably also needs to taper to displace enough or be adjustable.

So for example I tried the acrylic bar method but was unable to fit enough bars around the bottom to displace liquid enough at the top.

Maybe I need glasses with square sides...

Use casting resin poured into each tapered glass. Let it harden then remove. Clean up top edge and polish. Add small half domes around top and bottom as spacers. If the clear solid plug is domed on top, the poured liquid just flows down the sides.
MR

Maybe this will help, take a look.

http://www.eplastics.com/Plastic/Adhesiv......odP3y-vw

Thanks Bill, those are the exact solvents I am using. I was somewhat amazed to find out how much trouble it is to get an acrylic joint to be water tight! What is the world coming to?

Does anyone have more information about casting resin? is it very clear?

I use Castin Craft resin for my Sausage Finger Illusions. Although I paint over it, the resin is very clear. You can buy it at Michael's. http://www.dickblick.com/products/castin......g-resin/

You'll need both the resin and the catalyst (sold separately).

I have also played around with a casting resin bought at Wal Mart that is commonly used to resemble water in glass vase flower arrangements. Although it dries, it has a slightly softer consistency when cured... much like a very, very dense rubber. Since Wal Mart changed their craft departments, they may or may not still stock it, but Michael's or Hobby Lobby should stock it, I'd think.

Either should work for your project.

When I worked in a factory, we used casting resin to place our assembly parts in to hold them. That resin was orange color like resin glue that you mix.

There is a resin type that is used to form a gloss surface for table tops.
There is also a castable version of the polyester resin that can be cast in layers. It is "water clear" and really polishes up nicely. Unfortunately, it scratches quite easily but can be cast into virtually any shape.

These are two part catalyst (hardener) and resin. There is also epoxy resin that is a more yellow rather than water clear.
Depending on what you're interested in and what you would like the final material to look like, you have lots of options.

Doug

http://www.dreamfactory.com/magic/multum_parvo.jpg

http://www.bazardemagia.com/producto/392......le_offer

wow seems like they should at least send me a copy

They will just send them $60.