Thread: My Spinning Tunnel

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This year, I am finally going to build a Spinning Tunnel prop. Even with my background in electronics, I decided to go with the traditional "Bridge & Rings" design (instead of the new Laser method).

I have spent months playing with the design, combining features from those who have spun before me with some ideas of my own. The resulting design looks very promising... on paper.

My first question was which type of carriage wheels to use: 12" bicycle rims ($15 at most swap meets) or 6" lawn mower wheels ($7 at Lowes). Both have their advantages. I really wanted to use the 6" wheels, but needed a way to keep the tunnel rings aligned on them (not a problem with rims). The deciding factor came when I found a box of garage goor parts, including a bunch of the small rollers that go in the track. I would mount 2 rollers at each tire, one on each side of the ring. That solved, I moved on to the really tricky part: the bridge.

There has been a pile of construction material a few blocks from my house for several years now, including dozens of open truss beams of varying lengths. In my mind's eye, each one was half of a bridge through a Spinning Tunnel! However, I haven't been able to find out who really owns it to see if I could "borrow" two beams. So, I designed my own.

Since I'm building my bridge entirely out of wood, I am making it 16' long. If my calculations are correct, it should be able to carry 6 - 8 people with very little bow. Of course, 16' is, in my opinion, too short for a good Vor... um, Spinning Tunnel. So, I am adding mirrors at the ends to make the tunnel appear much longer.

Actually, I COULD have made it much longer, since I figured out a way to have a center bridge support without obstructing the tunnel. But, 16' actually fits better into the overall maze design.

Also, I originally planned on the rings being 10' in diameter, but reduced them to 9' 6" to allow the entire prop to be housed in a structure using only 10' building materials (wood and steel).

And speaking of rings, to be able to cut out the 48 segments of plywood exactly the same, I have designed two jigs: one to cut each piece from the sheet with the exact inside and outside curves, and the other to cut the mating edges at exactly 22.5 degrees.

The final piece of the puzzle was the design of the carriage assemblies. Should I use perforated angle, perforated square pipe, 2x4s, plywood, or some combination of any of the above? I don't weld, or I would probably use 1" square pipe.

After probably 20 or more possible designs, I finally ended up with one that is relatively cheap, easy to build, looks nice, and is easy to disassemble and store (takeapartable, as my wife would say). It will be built from 2x3s, 2x4, plywood, and perforated angle.

Of course, all of this is still "on paper". I'll find out in the next couple of months how well it translates to reality.

By the way, I have decided NOT to post my designs on here until after I have built and tested the entire prop. Two reasons. 1) I like to learn from my own mistakes, and I would hate for someone to tell me what I'm doing wrong before I have a change to find out on my own. 2) What if someone uses my designs to build one before I get mine finished and there is a design flaw which results in someone getting injured? I would feel terrible getting sued.

However, I promise to take lots of WIP pics and post them (along with the rest of the facade and maze). I start building the anchor wall and facade this weekend. Once the facade is up and covered (to act as a privacy fence), I'll start on the tunnel.

Thank you to everyone on here who has spun before me and posted their pics. I couldn't do this without you.

Oh, and since I can't call my prop a VORTEX, I have made up my own name for it: The Spunnel. (yeah, a lot of thought went into THAT)

Wow! That is ambitious. How much space is it going to take to store it?

I built a laser vortex tunnel (full sized, 50 lasers). I had to re-engineer the pulley system a couple of times to get it to spin. Mine is 9' in diameter. I was amazed at the power it took to spin it. I fried two motors in the process. I think I ended up with a 1.5 hp motor. I'm sure most of the draw is getting it up to speed. I cant imagine what it is going to take to spin your Spunnel, 5 hp???

Anyway I'll watch for updates. Good luck.

I love yak tunnels. I go to a haunt in town every year and pay my $25 for that 20 seconds of Wow factor. I would love to build one of these but it is just too large to store.

The spinning tunnel would be the easy part. I think the hardest part is the support bridge down the center of the tunnel. The supports are on both ends and nothing from the start to the finish. The mirror is a nice idea, it would really mess with your mind.

I would say a commerical vortex tunnel is around 14-18 feet...feels more like 40 by the time you walk down it. I do not think your distance of 16 is that far off.

It is a big undertaking and would love for you to pull this off in 3 months time. Seems possible but you will have to tweak it, because nothing turns out perfect.

Storage is always a major factor whenever I design a new prop or reusable facade (like my Pirate Ship). Fortunately, I have three storage units (10x10, 10x5, and 5x5) just for Halloween props and decor. The three rings of the Tunnel itself are made up of 16 segments of plywood, each about 4' in length. They will either be bolted or screwed together, and therefore will be takeapartable. The three carriage assemblies will be stored intact, but even though they are 8' long, they are only a few inches wide and not too heavy. The only component I'm struggling with is the bridge. Well the Open Truss Beams, actually. The bridge platform will be in two 8' sections, but the sides are 16' long x 3' high, and I DON'T want to take them apart. However, I do have ample overhead storage space inside my garage, and I suspect that is where they will live... until I get a 10x20 storage unit!

All together, the carriage assemblies would equate to storing an 8' tall grandfather's clock. The ring segments will be stored in three bundles, each about 4' x 1' x 1'. The two bridge platforms are 8' x 2' x 2.5" each. The only other components (besides the beams) are the tunnel fabric, the drive motor, and the 8' perforated angles that connect the carriage assemblies.

PROGRESS UPDATE: The 34' anchor wall and an 18' interior maze wall are up. We also installed an angled sill for the facade wall (so it can sit flush even on the sloped driveway). Next step: build and raise the facade wall.

UPDATE: Almost finished!

Ring Jig: I made a jig to cut the 48 ring segments to the exact arc needed to form a 9' 6" ring when connected. It was actually two sections. The first section was a router (with a cutting bit) mounted to a 6" x 12" scrap attached to the end of a 4' perforated angle with a pivot bolt at the other end. The second section was the 4' x 8' tray that the 1/2" plywood fit into. It had a "bridge" across it with a teflon spacer sitting in a shallow hole. The pivot bolt from the first section fit into the spacer and was held down with a flattened bracket. To operate, the plywood was placed in the tray and slid down about 6" past the end. The router was lifted and moved to one side, turned on, then slowly moved to the other while cutting. When finished, the plywood was scooted down another 6" and the process repeated. It took about 2 hours to build and adjust the ring-cutting jig, but then I was able to cut all 48 segments (plus a few extra just in case) in about 3 hours. Maybe that sounds like a long time, but I never would have been able to cut them as perfectly using a jigsaw.

End-Cutting Jig: Now, I needed to cut each segment to the appropriate length. To form a 9' 6" ring, each segment would need to be 44.77" long (around the arc, not across the chord). After carefully measuring and marking one piece, I clamped down an aux table and a few well-placed stop blocks to my miter saw and cut each ring segment to the exact length.

Joining Jig: I made one more "jig" to align the segments while I drilled the screw holes. I laid out four 2' x 8' sheets of plywood in a 10' x 10' square (on my living room floor) and strapped them together. I then temporarily ran a cross-piece across the middle and tapped a small nail at the center point. Using string, I drew a 114" ring, then removed the cross-piece. Finally, I used all the end-pieces (I cut off in the previous step) to create a round "fence" of stop blocks along the ring. To use it, I set eight ring segments in place, up against the fence, and used a square of masking tape to hold them. The 8th segment needed about 1/8" shaved off to fit, but that was all. I then laid out eight more segments on top of the first eight (offset by half) and taped them down as well. Now that they were all lined up, I drilled four screw holes into each segment then inserted 8-32x1.25" machine screws with 2 flat washers and a lock washer. Since the pieces were not all exactly alike, I numbered them.

The Bridge: Anyone who has ever built (or even looked at) a spinning tunnel knows that the key to the entire prop is the bridge. It has to be long enough to allow for a nice, long tunnel and low enough to provide adequate head room, but still be solid enough to support several people running across it at the same time. Well, I did it! I built a 16' long bridge with a deck less than 12" off the ground, with ZERO DEFLECTION! I was amazed when I walked out to the middle and it didn't bow at all. I was expecting a quarter inch - maybe even a half inch of deflection. But zero? I even jumped up and down on it. And the most amazing part is, each side is made up of two 8' sections! That's right. The spanning beams are pairs of 8' long 2x8s strapped together. I knew I would want to keep this one to use again, but my biggest storage unit is 10' x 10'. So, I made the sides 4' x 8'. An added bonus: it even looks nice.

All of the pics are here: http://www.starkmadness.com/photos/t...s.php?album=88

I must kneel before the King of Halloween. That is one impressive project you have there.

I love these tunnels and a local haunt always has one running. I wish I lived closer to Henderson.

Wow!!! That is impressive.

had a terrible thought....what if someone throws up inside the spinning tunnel.....?

Originally Posted by DannyK

had a terrible thought....what if someone throws up inside the spinning tunnel.....?

LOL...You turn it up faster and keep laughing

FINISHED!!! Our Spinning Tunnel is completely finished! We attached and painted the fabric last night. It spins at about 4.4 RPM, which seems to be a perfect speed. Just thinking about it is actually making me dizzy again.

The fabric was a 20' x 40' pool cover cut down to roughly 17' x 30'. It was black on one side (perfect for the tunnel) and blue on the other (perfect for the delivery door flap made from the left overs). We attached it to the rings with staples and painted it with four different colors of fluorescent spray paint.

The drive motor was donated by a local company. It is an 1140 RPM 1/2HP Baldor. I slowed it down with a few parts from McMaster-Carr (I LOVE that site). A 2" pulley wheel on the motor's 5/8" keyed shaft is V-belted to an 8" wheel which gives me a 4:1 drop. The 8" wheel is keyed to another 2" wheel which is then belted to a 6" wheel, giving me another 3:1 drop. The 6" pulley wheel is locked to one of the carriage wheels (which the center ring rolls on). The carriage wheel is 6" and the ring is 9' 6", so that gives me a final 19:1 drop. Mathematically, this should give me a 5 RPM spin. I guess the .6 RPM difference is from load drag. The motor is dual-voltage (110v or 220v). I went with the 220v configuration since I had an unused 220v outlet in my garage (from the house's original dryer). And, it is the only outlet on that breaker.

I have taken a few in-progress pics, and will take a few more now that it is finished. I will post again once I have them up on my website. Also, now that I know it works, I will start working on a tutorial as well as lessons learned.