Da Vinci’s Flying Machine

The art theme for 2016’s Burning Man was Da Vinci’s Workshop. I was particularly excited with this theme because I knew it would bring out even a greater number of mechanical-related builds, projects and art pieces to the event. But more so, this theme provided me an excuse a reason to finally build something that I had been thinking about for some time.

I had always wanted to place a rotor (think helicopter) on a bike (or better yet, trike), which would spin when the rider pedaled. This project seemed to fit nicely with 2016’s Burning Man art theme. On top of that, I had recently retaken possession of the Torker Trike. How could I not build this?

Hence the build that came to be known as Da Vinci’s Flying Machine.

Why a right-angle drill attachment?

What is this thing and what will it be used for?

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You’re looking at a right-angle drill attachment.

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This little device performs the same function as a 90° gear box.

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…specifically, to accept power (torque) onto the input drive shaft and to turn the direction of drive through 90 degrees (a right angle) to the output drive shaft.

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The drill attachment achieves this functionality in the same way a 90° gear box does — through the use of two bevel gears.

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Using this apparatus is more cost-effective and practical than building my own 90° gear drive system or gear box. And why do I need a 90° drive system? Because the power from pedaling the trike [where the sprockets are aligned vertically] needs to transfer to the rotor blades of the Flying Machine [where the rotor is aligned horizontally (or at 90° to the trike’s drive system)].

[Although, building a gear box would have been a fun project in itself; after noodling around with some designs and looking at the cost of supplies {gears are expensive!}, I determined that this piece of the Flying Machine project could best be attained with this right-angle drill attachment. Plus, I found one for less than $12. – Ed.]

Building the rotor

In the spirit of repurposing, I picked up a used ceiling fan from the “free” section of Craigslist. [This was either in 2014 or 2015 – Ed.] The fan has been sitting in my shop [taking up space] until now.

First thing I did was remove the fan blades and their brackets. These are the pieces I repurposed for the Flying Machine’s rotor.

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Next, I prepared a 5″ blank metal plate ($1.18 from Home Depot) for attaching the fan blade brackets and blades to.

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First I drilled a 3/8″ center hole.

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This hole is for the rotor’s main vertical shaft.

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Then, using a compass, I marked a concentric circle on which to align the holes to be drilled for the fan blade brackets.  Note: Alignment is crucial here; take your time and get this right.

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Use whatever method suits you to ensure equal spacing between the fan blades.

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Once marked, drill the holes.  I drilled pilot holes and then stepped up to a 1/4″ drill bit. The finished plate is pictured below.

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After the holes were drilled I attached the fan blade brackets using 1/4″ hex bolts and nyloc nuts.

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…And then installed the rotor’s shaft. I used a 3/8″ bolt for the rotor’s shaft.  Note: all nuts used on the rotor assembly are nylon insert lock nuts (aka nylon nuts).  I used these type of nuts because the expected vibration and motion on the assembly.

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…And, finally, install the rotor’s blades. In the picture below the rotor’s blades have been installed and the rotor’s shaft is inserted into the 90° drive. Note: another plus of using a right-angle drill attachment for the 90° gear box is that the drill attachment’s chuck makes attaching and removing the rotor [e.g. for transport] very easy.

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The Drive System — freewheel, sprocket, and other bits

With the rotor built it was time to move on to the drive system. The Da Vinci Flying Machine’s drive system consisted of simply connecting the trike’s rear (live) axel to the right-angle drill attachment via a long length of bicycle chain.

I purchased a 13-tooth sprocket to attach to the drive of the right-angle drill attachment and a 22-tooth freewheel to mount on the live axel. Also purchased the appropriate freewheel adaptors (see photo above and parts list below.)

In the photo above the 22T freewheel is seen installed on the rear axle.

In order to mount the 13T sprocket (5/8″ ID) on to the right-angle drill attachment’s 1/2″ drive I needed a spacer (shown in the photo above).

The photo above shows the 13T sprocket, the sprocket adaptor, and the spacer attached to the right-angle drill attachment’s drive shaft.

Parts list for the above…

[Update: For the final version of the build I swapped placement of the freewheel and sprocket. In other words, I used the 13-tooth sprocket on the trike axle and used the 22-tooth freewheel on the right-angle drill attachment. For more detail see the Comments in this post: The Da Vinci Flying Machine in Action.]

Sourcing the chain for the drive

I didn’t realize at the onset of this build, but the project ultimately required about 14 feet of bicycle chain.

I had some used chains in my parts bins, but some were in pretty bad shape (i.e. rusted, froze, etc.). After collecting usable pieces I was still short. At this point I could have simply purchased new chain, but what’s the fun in that.

Rather than purchase new I visited my go-to place for inexpensive bike parts to find all the chain I needed. The Kiwanis Bike Program (pictured above) is a great source for bikes, frames, parts, and more, AND at a fraction of the cost of new. Oftentimes a small monetary donation is all that is asked for parts. [AND it goes to a good cause. Check out http://www.kiwanisbikes.org for more info – Ed.]

After sourcing enough chain it was time to clean the dirty ones. I have a ultrasonic cleaner that I picked up at Harbor Freight that I use as a parts cleaner for my dirty greasy bike parts.

In the photos above you can see the “before” and “after” shots of the same chain after going for dip in the ultrasonic parts cleaner.

Building the rotor tower

The rotor had to be mounted high enough above the rider’s head to prevent accidental contact with the rider’s head or hands. And, of course, the tower had to be strong enough to support a spinning rotor.

I did not want to weld the rotor tower to the trike frame because I wanted to be able to mount and unmount the entire assembly (tower and rotor) when desired. So, a bolt-on tower was necessitated.

The Torker Trike has four pre-drilled holes through it’s rear frame (shown in the photo above).  These holes are provided to mount the trike’s rear basket, however they also support installation of a rear canopy structure.

I chose to use these holes to mount the rotor tower.

The simple design of the rotor tower (shown in the photo above) consisted two open rectangular frames (a top and bottom) welded to four corner supports. Keeping the bottom frame open allows for the drive system’s chain to run up and down through the middle of the tower — lending a cool steampunk aesthetic, as well.

For the top and bottom rectangular frame material I used my go-to source of steel — repurposed bed frames (leftover lengths from previous projects pictured above). Used bed frames can be found very inexpensively off of Craigslist or at your local thrift store. I have even found them for free in Craigslist’s “Free Stuff” section.

For the tower supports I used my other favorite go-to material — EMT Conduit. For this project I used 3/4″ diameter EMT Conduit. 10′ lengths of this material can be purchased for less than $4 a piece at your local hardware store.

And, yes, I considered using the steel bed frame angle iron for the tower supports as well, but I felt the use of EMT conduit would look better as well as reduce weight.

I sized the tower’s bottom and top frames to match the depth between the trike’s two rear cross members.

Use a corner clamp (shown above) to hold the pieces in place for tack welding.

Pictured above is the rotor tower’s bottom support frame. Make an identical 2nd one for the top frame.

With the EMT cut to length use magnetic 90-degree welding supports to hold the EMT in place for tack welding.

Pictured above is the completed frame for rotor tower. Strong, Sturdy, bombproof.  Now to construct the rotor mount.

Constructing the rotor mount

Next, the rotor and right-angle drill attachment must be mounted to the top of the rotor tower. The mount needs to be strong enough to withstand the force exerted upon it by the drive system.

The design I came up with was a three-point mounting bracket to securely hold the right-angle drill attachment (shown above). Utilizing the left and right bolt holes intended for the drill attachment’s handle, I bolted the attachment to two pieces of steel (bed frame). I then drilled a hole through a third piece of bed frame just large enough for the attachment’s drive shaft spacer to slip through and easily spin.

Here’s another shot of the right-angle drill attachment mounting bracket (above).  The pieces are clamped and ready to be tacked.

Pictured above is the finished rotor mount.

Pictured above is the completed rotor tower and rotor mount (viewed from above).  Prior to welding, the mount was clamped to the tower and the tower bolted to the trike frame in order to position mount accurately for proper chain alignment of the drive system. This took a little adjusting of both the rotor mount above and positioning of the freewheel on the trike rear axel.

However, once correctly aligned, the drive system worked as planned. With the use of plenty of C clamps I was able to perform a roll test of the Flying Machine prior to final welding.