Behold the "DREMELCOPTER", perfect gift for the guys at the shop to share for break time, too bad I didn't finish it in time for Christmas. It's kind of a spin-off (no pun intended) from my Convection powered, counter rotating, kinetic sculpture. Originally I hadn't planned on using a Dremel tool for power, I was going to cannibalize an old r/c car for the motor and speed controller, radio and servo. I forgot that I donated all my r/c stuff to the machine shop of a community college a few years back.
This baby can launch a 5 inch diameter fan well over a hundred feet up. The wind can make for lost fans too, already lost the first two on it's maiden outdoor launch session.
The first test launch was conducted inside my shop. My intention was for it to be a very slow speed launch to check if the spindle would disengage from the drive properly. The Dremel was on slow speed but the fan wasn't. Two flourescent tubes later the second test launch, this time holding my hand a few inches above the fan because I had no more spare flourescent tubes, glad I wore a glove. Check back soon cause as soon as the wind stops I'm goin' outside with a video cam!
BILL OF MATERIALS:
12"x12"x1/8" birch plywood
6"x6"x.037 birch plywood
3ft. length of 1/4" oak dowel
1-1/2"x1-1/2"x1/16" aluminum flat stock
1/8"x2-3/4" soft copper tubing
3pcs. 1"x1/4" self adhering rubber pads
3pcs. #6x3" FH machine screws, nuts and flat washers
1/8"x 2-1/2" steel round stock (I cut the shank from an old drill bit)
Titebond lll wood glue
laser cutter/engraver (all of the wood parts in this Instructable were laser cut)
wire feed welder
router table/drum sanders
Dremel tool w/ drum sanders, cut-off wheel, carbide burrs
1-1/2" hole saw (I added a cut in the drawing file, so this is no longer needed)
vise grips (swivel pad)
small paint brush
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Step 1: Short Movie
Sorry I havn't been able to take a movie of this outdoors yet, it's been very windy the last few days. Here's a short video taken indoors. I modified the fan unit by adding a sharpened point to give it a more dramatic effect and to give you an idea the force this has upon lift-off. I will be adding a video taken outdoors as soon as the wind stops blowing. Again I'm sorry I couldn't post the video as promised. Pete
Step 2: Assembling the Fan
Photo#1: I cut the fan blades from .037" birch plywood. The rim and hub pieces are 1/8" birch plywood and I used 1/4" oak doweling for the spindle.
Photo #2: I engraved reference marks on the center of each of the fan blades and on the fan rim to ensure the blades will be centered upon assembly. The Dremel spins counter clockwise so the pitch of the fan blades must be arranged as in photo #2.
Photo #3 The rim is attached to the fan blades by gently twisting each blade so the tabs on the end of each blade spans the rim, afterward the hub discs are glued to the fan one on each side. Then with a small paint brush apply a small fillet of glue everywhere the fan blade touches the rim.
Photo #4: To prepare the spindle, cut to 3-1/2" length, drill 1/8" hole 1/4" from one end and with carbide burr form a slot at the end, then shape the end as in photo #5.
Photo #6: I applied glue inside the bore of the fan hub then inserted the spindle untill it protruded about 1/16" above the hub.
Photo #7: I applied a small fillet of glue to all glued joints in this entire project.
Photo #8: The completed fan assembly.
Step 3: Assembling the Base/motor Mount
The base/motor mount assembly is the structure that forms a means of coupling a Dremel tool to the fan assembly.
Photo #1:The parts for the base and motor mount assembly.
Photo #2: I changed the design of the top of the motor mount.
Photo #3: Aluminum ring / Dremel tool.
Photo #4: Assembled base and motor mount.
Photo #5: Location of the 1"x1/4" self adhering pads.
Photo #6: Detail of the motor mount top.
Assembling the base/motor mount is quite simple, apply glue to the recesses in the MDF base, the slots in the stabilizer ring and the slots in the motor mount top and erect as in photo #4. The engraved side of the motor mount top faces up. After the glue has had some time to cure I applied glue to both sides of the aluminum ring and placed it into the corrosponding engraved recess on the top of the motor mount, applied glue to the engraved plywood ring and placed it over the aluminum ring. Clamped the motor mount and plywood ring then set it aside for the glue to cure.
Step 4: Assembling the Pylon
The pylon assembly houses the "nose" of the Dremel tool and holds a launch tube that the fan spindle rests in until lift-off.
Photo #1: The parts of the pylon assembly (the #6x3" screws are not here yet).
Photo #2: The pylon base assembly (shown attached to the motor mount top).
Photo #3: The pylon legs, top and tube assembled to the pylon base assembly.
The first step to assembling the pylon is having all the parts ready, the pylon base top needs the holes countersunk. Wood glue and a small paint brush should be close by. I assembled the base of the pylon from the top down. I ran three #6x 3" flat head machine screws through the pylon base top, nesting the screw heads in the countersunk holes. apply glue to the under side of the pylon base top followed by seven 1/4" poplar pylon spacers with glue applied to the bottom of each. Next the 1/8" birch plywood motor mount spacer, it's got a 1-1/2" center hole where as all the other spacers have a 1.8" center hole. Finaly the 1/8" birch plywood pylon spacer. Clamp the assembly together onto the motor mount top with washers and nuts and set aside to allow the glue time to cure. After the glue has had a few hours to set I ran a 1-1/2" hole saw through the center of the side taking care to center the hole between two of the machine screws clamping the pylon base together. The pylon base is now complete and assembled to the notor mount top photo #2. To finish the pylon I cut a piece of 3/8" soft copper tubing 2-3/4" long and deburred the ends. Next I applied glue to the slots in the pylon base top and placed the pylon legs into the slots, glued on the pylon top and inserted the copper tube to leave about 1/8" protruding through the pylon top Photo #3. Set aside for glue to cure for an hour or so.
Step 5: Drive Pin Fabrication
To fab the drive pin I cut the shank from a 1/8" drill bit into two pieces, each 1-1/2" long. To make them fit together well I fish-mouthed the end of one of them with a 3/16" diameter grinding bit in my Dremel tool. I clamped the opposite end of the fish-mouthed piece directly in the ground clamp of a wire feed welder, held the two pieces together to form a "T" and welded them together. Cleaned the weld with a small wire brush and trimmed the T end to 7/16".
Photo #1: The completed drive pin.
Photo #2: A view of the drive pin chucked in the Dremel tool, coupled to the fan spindle.
Step 6: The Finished Project
Photo #1: To finish all I needed to do was tighten the nose end of my Dremel tool, plug it in and drop in one of the fan assemblies. Always launch the fans outdoors!
Photo #2: If you fail to launch outdoors something like this is probably going to happen.
To launch a fan simply drop the fan spindle into the launch tube(it will align itself onto the pin) keep body parts away from it's ascending trajectory and turn the Dremel tool on briefly. Good luck retrieving the fan afterward.