# Steel-Steel Connection for Kabuki



## SanTai (Sep 15, 2011)

I am considering building a solenoid controlled kabuki drop system and I need some advice on the the "hook" that you hang that thing you want dropped.

I am thinking about a pin on a steel plate as in the picture(not in scale or anything). Imagine that you hang your drop on the pin, how would I get the max strength of the "hook".

Should the pin be welded? Or should I have a hole in the plate and place a bolt with a nut? Or should it be constructed from piece and use bent steel instead?
Which kind of connection gives the highest strength too the complete hook?


This might have been discussed earlier, however I couldn't find anything.


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## Schooltech (Sep 15, 2011)

Welding is essentially turning your two pieces of steel into one, assuming that your "hook" is of a decent size diameter then a bead all the way around should give you way more strength than you need to hang a drop. I have found bolts more likely to bend, remember the diameter of the core is what you are looking at not the threads. a 1/2 bolt has less strength than a 1/2 rod. I would suggest a mig weld if you have the rig.


SanTai said:


> I am considering building a solenoid controlled kabuki drop system and I need some advice on the the "hook" that you hang that thing you want dropped.
> 
> I am thinking about a pin on a steel plate as in the picture(not in scale or anything). Imagine that you hang your drop on the pin, how would I get the max strength of the "hook".
> 
> ...


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## Van (Sep 16, 2011)

SanTai, I'm afraid I might have more questions than answers for you but I think we can find you an answer inthe end. A lot of the "To weld or not toweld" question can be resolved with a few simple questions. what kind of load ? How big is the drop? are you going to have a single point that will release the entire drop or can you rig 2 points? 
I'm a little confused by the steel rod sticking out from a plate where is that going to attach ? how is this to be activated by a solenoid ? I have built similar contraptions in the past and I have typically used a plate, mounted the solenoid on one side of the plate then use a steel pin going through a hole in the plate. The Pin would be pulled through the plate with the plate acting as a stop for a ring or hook that had the load on it. Essentially: as the pin drew back the plate pushed the ring off the pin. Does that make sense ? If not I can probably go take a picture of one I hae made up.


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## Van (Sep 16, 2011)

Schooltech, I don't know exactly what happened but it appears your first post was moderated by our Overly efficient Spam protection. I Approved your post and reinstated it.


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## coldnorth57 (Sep 17, 2011)

I am all for build it your self BUT when the wheel is already built....
Try this
Kabuki Drop Systems | Kabuki Drop


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## MPowers (Sep 17, 2011)

I have almost always used a straight pin rather than a "hook". I know you don't really mean "A Hook, it's just that word make me think of a thing that can foul and not release. Using a solenoid or pneumatic cylinder to pull the pin. Picture two flat plates, about 1" square, facing each other about 1" apart, with a 1/4" hole in the center of each. Place a 3/16" rod through one hole, through the loop, eye, grommet, etc. on the drop, then through the other hole in the other plate. Pull the pin and the drop falls. One solenoid or cylinder can pull a couple dozen pins a once. This is only one of many methods all as good. Just one I have used and like.

Your "Usual" Kabuki drop is a very light weight material, each support point handles a load usually measured in ounces rather than pounds. So, I am curious about your concern for strength. What is the material, how heavy, how many support points? 

One Kabuki I dropped was simply 6d finish nails driven into a wood rod. Nails up for set-up. Rod rotates 90 degrees for the drop. (I also used a variation of this method to individually drop, one at a time, 46 parachute wedding presents for "Big Love").


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## SanTai (Sep 18, 2011)

The reason I asked about this was that we used a simple drop with pins on a string quite recently for a show. I then stared thinking of how I would design a "real" kabuki drop system that would work almost always, be safe and electronically controlled.

The strenght part is that I feel is that in the event that one/few units would fail it would not cause catastrophic failure. If all but one of the units release, you that got the drop hanging in one point. If that is a too large a load, I would want it to be constructed in such a way that it could fail without falling apart. A drape falling uneven feels better than falling uneven and bringing pieces of metal down with it.

I would not want this kind of drop hanging one only one point:
Rammstein - Intro & Rammlied, Live @ Metaltown 2010 - YouTube

My idea of the plate was that when released it would fall back. The reason I am not the greatest fan of the pin through two plates is that it limits what you easily can drop without an "adapter".


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## MPowers (Sep 18, 2011)

I don't really understand what you mean by "adapter" or why you would think one is needed. I have used the pin method to drop standard curtains using only the grommets that are installed, objects and soft goods with cord loops, solid items with holes drilled in them. The pin method is one of the two most common types of commercial drop. The other is a clamp release, which I have also used. The commercial version usually uses one clamp and actuator for each release point. Most recently I used a shop built, clamp method for a full front curtain drop much like the video you posted. The fabric was a 30' high x 50' wide, light weight Chiffon and had to fall on top of two performers. Obviously any thing hard or heavy like a grommet was out of the question. For that I used two hogs-trough sections, face to face to form a double stem "T". The "T" was hinged at the top with heavy duty spring loaded hinges that pinched the two stems together. The full length of the lower edge of each mating "T" was lined with 1" etha-foam rod, split down the middle, so the two rounded faces were pressed together. We roughed up with shiny surface with a little steel wool for "grab" and the fabric was pinched the entire 50' width between the etha-foam pieces. The actuator(s) were 4" x 1" stroke, pancake cylinders spaced every 10' along the mechanism. The cylinders were attached to the outside face of one side of the stem. The rods were placed to the inside and poked through a hole drilled in the stem so that when activated, they pushed the stems apart, looking a little like someone's arms and legs when doing a jumping jack. The air was supplied by a small portable tank mounted on the batten and actuated by a solenoid valve triggered by the SM. One of the advantages of this system was that should the mechanism fail for any reason to drop the fabric, a sharp tug at either end would pull the slick fabric out of the clamp and it would continue to fall, like a zipper all the way across. Not the effect the director really wanted, but acceptable if necessary (never had a failure in three weeks of 8 performances each). 

Each method has advantages. The Pin method can be the most economical as one actuator can operate many release points. The drawback is the object must have a hole in it. Advantage is that the object can never fall prematurely. The clamp method Often (but not always) requires an actuator for each release point. One advantage is the the clamp can work on any flat surface. Disadvantage is the object can possibly fall prematurely.

One of the advantages of the pin method is that it "Always" works, not just "Almost Always". "Almost Always" is not acceptable.


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## SanTai (Sep 19, 2011)

Intresting, I am not quite sure I understand the workings of your system. If it works like I think it sure is innovative, but I don't understand how a grommet could be worse/harder/hevier than a heavy duty spring.

This is what I meant with an adaptor: European Kabuki Drop Mechanism

This is kind of the design I was thinking of: MagicFX | Make your audience scream!

(It don't know if it got all the features I want though.

When it fails. Because it will or at least plan for it. I would like to be able to with force pull it down and the safty aspect of it. So that you could solve this kind of error:
Megaphone, Kabuki Drop Accident. - YouTube
It wouldn't be pretty but if you solve it in 10 seconds rather than having a climber start climbing if you are in a large arena.


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