Spinning Tunnel that you Walk Through

Welcome ghouls! Yes, the "spinning tunnel" page, also known as the vortex, however I have read that 'vortex' is a trademark so I didn't use it as the page title.
I saw this at a Haunt Convention and it really blew me away. It's a rotating tunnel with lights that you walk through and the perception is that you are spinning, not the tunnel. Very intense effect. Anyway it didn't look that difficult to construct. You can buy one for about $8000. Not in my budget so we had to do something else. After researching others plans and attempts to build one we undertook this project in 2010 and were successful. The total cost of materials was around $2500 at that time. The 2 sources I used are as follows. The basic design and materials came mainly from Terry's site while the motor and other materials set-up was from Jeff's site:
http://www.scary-terry.com/vortex/vt.htm
 http://timepasses.com/vortex/vortex3.html

Our version of the tunnel can be seen in the video below.




Unfortunately we had to shoot the video during the day. At night with the blacklights the effect is quite amazing.
Here is the basic breakdown and the sources we used for the items.
1) The motor. I am far from a gear head. I am great with computers but not someone who can take out a dryer motor for example and rig it up to power this thing. Plus there is the safety factor. You don't want to have to worry about this thing heating up and burning the place down. You want to be able to switch it on and have it run all night with no problems. That is what happened. I recommend Grainger as your source for the motor
 Model number 2Z850B, 288HP.  This is a worthwhile investment. Now the motor is wired for AC power but you have to properly connect it to an external power source. I had our friendly electrician wire and properly ground the motor as well as attach a switch which can be turned on and off. It is a nice safety feature to have.

2) Hoops: This is the other critical element of the project. The double thickness segmental overlapping plywood construct shown by 'Scary Terry' in his webpages is what we decided to go with. This is a very solid mechanical construct. I was pleasantly surprised. If you use the link to his site above you will see where he provides the contact information for ordering the hoop segments. They make them from a software driven template. They cannot be made more accurately. This is superb plywood with virtually no voids. All of the holes for all of the bolts are predrilled. Each hoop is made form a total of 16 segments (8 overlapping 1/2 inch segments for a total of 1 inch thick).I ordered the hoop segments and they were made and shipped within a few days. I treated all of the individual segments with Thompson's water seal. You then simply bolt the segments together using whatever you like. I used 1.5 inch stainless steel bolts with a smooth washer on each side and an additional lock washer on the nut side.

3) Wheels. This was a little tricky because the hoop rim thickness measuring 1 inch has to fit inside the wheel channel. Bike people don't list that dimension accurately in their descriptions. The first set of wheels I bought were listed as 1.25" and were actually .875! I had to exchange them. Finally what I did was I went to the local bike shop with the wood hoop segments and showed them exactly what was supposed to happen.
The wheel brand they came up with that worked was : Sta-Tru wheels, 20" #FW2075SS 3/8 axle with flat for 5/16
The actual outer diameter of the wheel is 17" (even though it says 20!) This doesn't matter. You just need to make sure the one inch hoop thickness will fit in the wheel channel. Don't worry if it's a tight fit and you have to press it in there. It will still work.

4) Miscellaneous wood/hardware: For the bridge which has to be very well made, I worked with a carpenter friend. He was able to get quality wood and materials at a good price.

5)  Fabric. Yes, the fabric. usually overlooked, but there is a LOT of it. We used flame-retardant 12 oz commando cloth. 54" roll  x 50 yards.
This company was lightning fast in delivery and service and the fabric came in good condition

6) 10 x 20 canopy with enclosure kit. Actually once I screwed the canopy bases to 2x4's it did remain pretty stable. We used 2 foot PVC extension segments to get the canopy high enough to accommodate the hoops. This saved some money as we would have needed a 12 x 20 canopy easily. The structure survived a Noreaster and very humid low pressure system over a 3 week period. If you need to get a canopy I recommend Shelter Logic brand and I used this company which was excellent in terms of delivery time, packaging , price and overall service

Those are the principle elements. There was also some fluorescent paint, black lights etc.
What follows now are some construction details and troubleshooting points.

This is the extension we added to the canopy. 2 foot PVC pipe bolted into the bottom segment of the canopy. There is about 2" of piping inside of the metal pole.

These 2 images above show the motor mounted and hooked up to the bike wheel closest to the motor under the second (middle) hoop. The motor comes already mounted on a square piece of plywood. We created a platform for the motor which is attached to the wheel carriage.The feet of the motor have additional slots for screws which we used to anchor the plywood base of the motor into our platform. The belt used is a 100 inch v-belt. The actual length/circumference probably does not matter. We wanted to set the motor away from the traffic. This distance seemed to work fine.  Notice the plug and on/off switch. We fortunately did not have to switch the motor off for any reason! The belt is shown on the second to smallest pulley. Largest diameter pulley = fastest speed. I had it on the far left pulley and the rotation was way too fast. Dropping it down to the pulley shown yielded around 7 RPM which was perfect!
Now the belt does not have to be super tight. I did not measure the belt tension. I believe as long as it turns the wheel when the hoop is resting on it you should be fine. Don't worry if the wheel is turning and the hoop isn't at first. Just help it along for awhile and it should eventually start running on its own. If not you may need to sand down the edges of the hoop. If you are using these wood hoops and the rotation is sluggish it could be because of moisture. After it rained here or there was a low pressure system that went through it always took longer to get the hoops running properly. Once it took about 1-2 hours! But it ALWAYS worked ultimately.

The images above show the middle hoop sitting in the wheel with the belt in it. I was very concerned when I first looked at this how in the world this would rotate with so little apparent contact with the side rim. With the belt occupying the same channel as the wheel, there is about 3/16 inch depth vs around 1/2 inch without the belt. The belt is 3/8" thick. Not to worry though. It totally works! We ran the thing for hours and no derailments!

Next 3 videos point out certain troubleshooting tips regarding hoop and bridge construction

Some bridge construction details are shown. As mentioned in one of the videos, we modified Scary Terry's design by shortening the bridge span slightly, going with an 18 foot length vs 20. Shortening the length allowed us to utilize single 18 foot long 2x10's rather than splitting the bridge in half. The 2 x10's sit on 4 16" long 2x10's that are bolted to the 2x10 door frame. The shorter pieces stand inside the door frame. Then 4 additional screws bolt the bridge 2x10s to the outer frame directly. There is an inner 2x4 subframe. Then for the floor, we just lay down some plywood pieces. The bannister sits on the 2x10's and is 'clamped' onto the sides by short segment 2x4's which span the joint between the bannister and the 2x10. There is one on either side for each column. The railings are screwed to the door frame at either end.
This was a very secure and stable construct. We often had up to 6 people on the bridge at one time!

Final entry for this page is a video below showing some of the wheel carriage details. As far as storage goes, it's not too bad. I left the bridge intact and put it on its side in the garage with the bannisters behind it. The wheel carriages also were left intact and placed along one wall in the basement. We have a back storage closet that I was able to put all the hoop wood in. The hoops were broken down into about 4 pieces each.








ADDENDUM: If you have followed the build for 2011 you will notice we were able to reassemble the entire vortex very quickly and it ran very smoothly without a glitch! So we have confirmed this set-up is durable and thus far weather resistant! In 2 years now I do not see any sign of hoop warping even after exposure to extreme New England weather! When we take the hoops down we do not break them down into single pieces but rather 2-3 segment sections. We lay them flat in the basement over the winter/summer.I should mention that the commando cloth seems to get a little frayed on the ends after use, and we really had to stretch the pieces the second time around to get them to fit, but they do stretch out. We will probably tape the ends next time before stapling. I think if you can afford it you might want to consider the 16 oz commando cloth if you plan to use it a lot. We should get by using the 12 oz sheets just one night a year for at least a few years.