# Operational Windmill



## Footer (Aug 25, 2010)

You are working on a production of _Oklahoma!_. The scenic designer has asked that a 30' tall windmill be placed onstage. It needs to have a foot print that is no more then 5x5 and it also must be able to be moved on and off stage by no more then two stagehands. The designer has found a fan for the windmill at a local scrap yard that is 4'6" in diameter and weights 40#. He has asked that the fan be able to spin at no more then 4 rpms. The rest of the windmill should be built in shop and resemble an actual windmill, such as this:




The producer has charged the shop with building this entire show to fit in as few trucks as possible for both shipping and future rental possibilities. 

What materials would you build this out of? 
What kind of motor would you use to operate the windmil? 
How would you build the mechanism that holds and powers the windmill? 
How would you deal with the footprint and weight of the windmill? 
How would you deal with the trucking issues?

As usual, if you consider yourself a professional please wait one week before posting.


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## MarshallPope (Aug 25, 2010)

Just a few thoughts - 

My initial idea would be to fly the top portion of the windmill. This would save on the bulk needed for the bottom of the wm, so that it would be easier and safer (less top-heavy) to move. 

I would build the bottom of the wm out of either angle steel or 1x3s and 1x2s, depending on the durability needed and budget. Each of the four sides could be built separately, and then pieced together onto a wagon to move on- and off-stage. A flown top part would make it safer to have a disassemble-able frame. The fan could be lowered into a slot in the base to keep it still. 
It looks as if there are pipes coming down the center of the wm. Those could simply be painted lengths of PVC placed into brackets on the wagon.


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## erosing (Aug 28, 2010)

This question seems very familiar for some reason.


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## MPowers (Sep 5, 2010)

Footer said:


> What materials would you build this out of?
> What kind of motor would you use to operate the windmil?
> How would you build the mechanism that holds and powers the windmill?
> How would you deal with the footprint and weight of the windmill?
> How would you deal with the trucking issues?


 
To answer the questions one needs to ask some questions. In another post, I'll pose some parameters and then answer along the lines established.

The questions may seem to be fairly obvious but need to be asked.
BUDGET. What is the materials and labor budgets?
FACILITIES . is the shop a commercial shop, university, LORT.......?
CAPABILITY. What Equipment is available, i.e. CNC, full metal shop or two saw horses and a saber saw?
SKILL LEVEL of shop crew, Pro or student or....
TIME, what is the length of time available for the project, how much of that time can be devoted to the windmill

When these questions are answered, then you can make decisions that will answer the OP questions.


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## Footer (Sep 5, 2010)

MPowers said:


> To answer the questions one needs to ask some questions. In another post, I'll pose some parameters and then answer along the lines established.
> 
> The questions may seem to be fairly obvious but need to be asked.
> BUDGET. What is the materials and labor budgets?
> ...



Consider this project occurring at a LORT A/B house with a typical budget of those shows (adequate but not extravagant). The shop would be capable with traditional saw and lumber tools as well as standard steel tools that would be found in a typical LORT house (Cold saw/welder/bandsaw/drill press/vertical mill). 

This question is really meant to answer the weight issues, trucking issues, and automation issues.


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## Traitor800 (Sep 5, 2010)

MPowers said:


> To answer the questions one needs to ask some questions. In another post, I'll pose some parameters and then answer along the lines established.
> 
> The questions may seem to be fairly obvious but need to be asked.
> BUDGET. What is the materials and labor budgets?
> ...


 
Also add to that what are the size limitations, is this windmill touring in a 56' trailer, a sea container or something small like a van?


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## Footer (Sep 5, 2010)

Traitor800 said:


> Also add to that what are the size limitations, is this windmill touring in a 56' trailer, a sea container or something small like a van?


 
As with any show anymore, the producer would like the entire pack to fit into as small of a space as possible. It is expected that the truck will contain two 26'x4' coffins of flats. The "no airspace" rule is in play.


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## MPowers (Sep 7, 2010)

Footer said:


> Consider this project occurring at a LORT A/B house .......
> This question is really meant to answer the weight issues, trucking issues, and automation issues.



LORT A/B house. That makes it easy. As roughly 20 years of my past were as a TD in a LORT B house, the budget, crew, shop etc are well known. The first thing I would do is a bit of research ( check out Windmill-Parts.com ) and then to have a meeting with the designer. The 4'-6" diameter wheel and the 5'x5' foot print are an issue. First the vane will have to be redesigned as a forced perspective or eliminated as the vane length is usually 1.5 to 2 times the diameter of the wheel. In addition, the smallest wheel I can find used on a real windmill is 6'. The next thing is the proportion. The base of a 30' wind mill is usually about 6'x8', so a 30' tower with a 5' base would appear to be abnormally skinny. I'm not a stickler for verisimilitude. It is a very good thing but not the end all of design. If absolute realism gets in the way of telling the story or creating the pictorial image needed, then it is not the correct choice, even though it may be historically accurate. Once the design issues are solved then the project would move to the shop.

Weight is not really an issue for trucking. Weight is more for the In and the Out. Obviously a road case would have to be constructed no matter what the 
Strength to weight ratio of the structure and the visual cross section of the support members pretty well eliminates wood as a material. Steel, Aluminum and Polymer composites (fiberglass etc.) are the narrowed down choices. The very open structure of a windmill tower makes the difference in weight between a steel and aluminum or fiberglass structure negligible, so the steel of a real structure is a reasonable choice. PVC pipe would be a good choice for the various piping necessary. 

A bit of engineering and cost analysis shows that simply buying a pre-built structure is only about $1200 to $1800 for a 27' tower, well within the budget of a LORT A/B house, and far cheaper than union labor and engineering for a one off custom structure. No point ot re-inventing the wheel, just start with the real thing.

My plan would be to buy the pre engineered structure and modify it to the 5'x5' foot print and then to further modify it into 3 (or 4) nesting segments. The truncated pyramid shape make this an easy choice. 

The rolling base design depends on the design concept, stage hand pushing, tracked, automation and a lo more so I won't go into that just now. 

The motor to drive the wheel would simply be a fractional HP unit with speed control, mounted at the head of the Windmill. There are thousands of suitable choices, but a 1/4 HP unit, suitable for frequency drive, possibly a package gear motor would be more than adequate. The real problem with 4 RPM is getting a motor geared down or slowed down to suit.

It's late, I've been working n this for a while. Hope this post answers some questions.


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## BrianWolfe (Sep 7, 2010)

Flatten it, Fly the whole thing, build out of welded steel. split into three sections. dc motor with control.


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## Footer (Sep 7, 2010)

This was an actual project I had several years ago at Lyric Theatre of Oklahoma. It was performed for the states Centennial Celebration. The issue we had with the whole thing was getting it to break down into nothing. Each leg was built out of 2x2 10 gauge box steel and sleeved together in the center. The X braces were built as one unit. and bolted on each side. The motor assembly fit onto the top. We welded caster plates on each leg and made boots for them. The motor assembly was what gave me the biggest issues. They did not want to purchase a VFD so we ended up doing a gear reduction with I think 6 sprockets (the designer did not want to see any sprockets so we had to do multiple reductions). The motor picture on my website was a test motor and not the final one used. 

Just as a point of reference, the borders for this show trimmed out at 45'. The upstage drop was 50'x70'. 



http://vansandtdesigns.com/portfolio/welding2/oklahoma-lyric-theatre-of-oklahoma/


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## MPowers (Sep 8, 2010)

> This was an actual project I had several years ago at Lyric Theatre of Oklahoma.



Kyle, how interesting. I worked at the Lyric, 5 seasons, back in the 60's. Back then it was located on the Oklahoma City University campus, you know the place. home of many famous theatre people, like.... me.... and then there was that lesser known actress Kristin Chenoweth among others. 

Back to the question at hand. Nice wind mill. I could tell from the description that a flat or "cut out" version would not suit the picture and from your comment about no more than two stagehands.....etc. that a 3D version was what was wanted.

I'm curious about a couple of things. The fan in the picture sure looks bigger than 4'-6" in diameter. Second it looks like the vane sticks out beyond the 5'x5' foot print or it that an optical illusion? 

Last, why the need for such a small pack? I thought about breaking down the sides but decided on the slightly bulkier, three nesting parts method as a labor (read $$$$) saving method for road set up and strike. The pack as I imagine it would be about 10' long and 5'x5' (the foot print) with all parts, fan, motor etc fitting within the space. 

Speaking of "air space" in packing, reminds me of Disney On Parade in '65. I was working a a rigger and spot op. 27 trucks, (all 48' then) and one truck had basically only three dresses on it. Picture a 16' diameter x10' tall bell shape on a rolling steel frame, covered with fabric to look like the skirt part of a dress. The girl sat in a seat at the peak, sticking out from the waist up and two stage hands pushed her around for the ball room number. They collapsed slightly in width to fit in the truck but it was just the three dresses. We thought about putting other stuff under them, but there was no good way to tie it down.


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## Cashwalker (Sep 8, 2010)

Looking at the pictures, seeing a Craftsman motor made me think of another source for the motor - a VSR drill. 
The trigger assembly has a lock nut, right? 
Set the speed, strap the drill in place, clamp the chuck onto the axle. DMX relay to turn on and off.


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## fredthe (Sep 8, 2010)

Cashwalker said:


> Looking at the pictures, seeing a Craftsman motor made me think of another source for the motor - a VSR drill.


You'd still need to gear it down quite a bit, though it is an interesting thought for a quickie motor.

-Fred


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## Footer (Sep 8, 2010)

MPowers said:


> I'm curious about a couple of things. The fan in the picture sure looks bigger than 4'-6" in diameter. Second it looks like the vane sticks out beyond the 5'x5' foot print or it that an optical illusion?
> 
> Last, why the need for such a small pack? I thought about breaking down the sides but decided on the slightly bulkier, three nesting parts method as a labor (read $$$$) saving method for road set up and strike. The pack as I imagine it would be about 10' long and 5'x5' (the foot print) with all parts, fan, motor etc fitting within the space.


 
The fan might have been 5' in diameter. I know it was not 6'. It was a real fan and was VERY weathered. It was missing its hub so I had to build one which was oh so much fun. The vain stuck up at a pretty high angle at a 45 degree angle upstage. I think I moved it twice before the designer was happy (all from a scissor lift with a welder strapped in 30' in the air....)

To get the thing to stand up we chained it off to a batten and flew it. We then put the fan blade on from a lift. 

As far as the pack goes, this show was built in 2007 when gas prices started soreing. The show was originally designed to fit into three trucks. We had a few theatres one the each coast that could only rent it if it fit in two. The producer basicly pushed us to do the exact same design as we had but it had to fit in a 2 truck pack, no questions asked. The show as being built in two shops, one of them being ours and the other one being Virginia Scenic. Virgina had one full truck coming with the house and smoke house and a few other odds and ends. We had to fit the barn, groundrow, windmill, props, drops, surrey (with the fringe on top), and wardrobe into the other truck. Therefore, I built the thing to break down into as few pieces as possible. I built it into the shop and we hauled it to the venue in one piece.


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## Footer (Sep 8, 2010)

Cashwalker said:


> Looking at the pictures, seeing a Craftsman motor made me think of another source for the motor - a VSR drill.
> The trigger assembly has a lock nut, right?
> Set the speed, strap the drill in place, clamp the chuck onto the axle. DMX relay to turn on and off.



Like this? 
The actor flipped a switch before the plane flew in. 






http://vansandtdesigns.com/portfolio/the-drowsy-chaperone/


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