Like any good engineer should I often look at my tools and ask myself â€œHow could this be more awesome AND more dangerous at the same time?â€
The obvious answer when looking at a Dremel was â€œadd a propeller.â€ This work is inspired by, but not derived from, the [now defunct?] Prop Rocket thing by James. Iâ€™m the wrong sort of engineer to design a propeller with any sort of real efficiency but itâ€™s my hope that this will make some one more knowledgeable give some tips or upload their own design. Since Iâ€™ve now lost a few of these out my window, I guess itâ€™s reached â€œflies well enoughâ€ status.
I showed this to a friend who requested a clarifications. This is a variation on those old toys which had a separate propeller press fit on to some type of handle. When the propeller is spinning fast enough the lift it provides over comes the friction fit that holds it down. At that point the propeller pops off and flies away. This is a version of that spun by a Dremel. It is not intended to fly away with your Dremel.
Warning: This is not intended to be a toy or even really be safe to use. Donâ€™t attempt to use this unless youâ€™re sure of your capabilities (are you certain your single walled print can hold blades together at Dremel speeds?). Even then I take no responsibility for you making one.
It's hard to print in my experience. I experimented with easier to print blade designs but nothing flew close to as well as this. I used full supports in skeinforge, which just added a little raft under the blades, and put my print head a bit lower then normal.
This is sized to it fit over the small sanding wheel Dremel attachment. It should fit on tight enough that it wonâ€™t pop off until an appropriate spin speed is reached. I suggest wrapping the attachment in tape or sanding down the inside of the hub as needed.
You will want it to stick to the top of the sanding wheel harder then you may expect. For best flight it will need to stay on all the way up to full speed and be able to release with a slight shake. The internal hub diameter is 15mm and my sanding wheel was 15.2mm. You may need to resize. The first time I fit each new one on I do so with the sanding wheel spinning slowly.
Make sure you and everyone else clear the stupid space before spinning it up. When Iâ€™ve been test flying these Iâ€™ve either been standing behind a glass door or window with my gloved handed holding the Dremel on the other side. I did one test flight inside and it hit the ceiling at an angle hard enough that it shattered.
Use at your own risk.