I am working on my own square circle. I am using those cylindrical cement forms you can get at any hardware store. This is my first attempt at a magical prop so I'm going to the cheap-o rout.

My question pertains to the height of the inner and outer cylinders. I have made my inside one about 1 inch shorter than the outer one. Before I get to the felt and further steps I was wondering if that seems like an acceptable height. Any ideas?

Thanks!

The inner tube usually is shorter than the outer one, and MUST be shorter than the outer square, but not so short as to be seen through the opening by someone sitting at a lower angle. ie seated children for example, or front row on stage. Many are made with the outer tube slightly higher than the square so it sticks up above the square when seated, but it does not have to be.
Another thought for a load chamber would be to use PVC plumbing pipe. I used a 10" pipe and split the chamber with fishing line like a tennis racket and can use it to produe the normal production items and then livestock at the end. The weight of the tube helps holed it in place should your "friend" get frisky.
Hope this answers your question.

This was a great help. I have also considered PVC. Since this my first adventure into the prop building world I am going the 'cheapest and least likely to irreversibly mess up' rout. Once I am more confidant I am certain I will go with PVC.

My SC is 16" high by 10" square. The circle is tooled leather cylinder 15 3/4" high. The 'you know what' is 8" stove pipe cut down, an a No. 10 can lid (coffee can lid) seals it. Kind of a Jail with 3/16" zinc bars in front.

I strongly suggest the use of velvet or velveteen in place of felt. It just works better. The $10 for the yard yielded enough for the inside of the square, the you know what, and another smaller SC. I have had folks 5' away and could not see anything.

MuleePete

Thanks or the recommendation on the velvet. That is the type of information I need because I am so green to the game. I'll a have to post pics when I get it done!

I have to agree that velvet works really well.

On the Allakazam Hat I built, the inner cylinder is set lower than an inch and I compensated by attaching a hinged loop to one side covered by velvet that I could catch with my thumb. This eliminates angles from overhead with stadium seating.

Dan

Go with the velvet as MP and Dan have already suggested. Felt will not do the job.

Look for a 1960s book entitled "Magic Handbook" by Science and Mechanics magazine. It comes up for sale often on the big auction site, and is one of the greatest resources you will ever find for many of the old standard parlor and stage illusions. Square Circle is in there.

Davin, to review or restateand clarify the guidelines listed above and a few of my own:

1) The height of the load chamber is determined by the highest viewing angle you are likely to encounter. You should not see the load chamber over the top of the square from the highest viewing angle. Actual height depends on the overall size of your SC and can be adjusted by adding a bump on the center of the front panel of the illusion. As Eric stated it must be shorter than the square but tall enough so the top of it can not be seen through the cutout from a low viewing angle. A fairly tight fit on the 3 pieces can make this easier to determine.
2) Cotton velvet is just about the only covering to use. When buying your fabric, check it in daylight at odd angles for sheen. You should not see any difference in the fabric as the light hits it at any angle. If you do, look for another fabric. I have found a vinyl backed velvet backdrop material (available from Filmtools on line)that does not streach when glued down. It is not quite as good as real velvet, but it is much easier to work with and is fine for a SC, but I would not recommend it for an AllaKazam hat type of design.
3) Make sure that the cutout in the square does not reveal the sides of the load tube. AllaKazam Hat type SCs reveal the sides of the tube and it is very difficult to mask.
4) a quality paint job will attract the spectator's eyes and make the illusion more believeable. Bright colors help hide the secret.

I almost forgot the most important thing..Have fun building and using your prop. Strive to perfect your craft with every new build!

Tim Silver - AGMagic