All posts by Darcy

Dayton Wing Mount

Experimental

I’ve run a Dayton in a hallway which resulted in the wing mount failing. The point of failure on the first break was right behind he tape in the front. The second failure was just ahead of the tape in the back.

We sat at the pub and contemplated (an important part of the design process). 🙂

Here’s the scoop so far. The Squirrel will rarely break for a couple of reasons. One is the wing held in place by an elastic. This not only allows a wing adjustment (and removal) but it has flexibility.

Secondly, the beam is cut to 1/8×1/16″ (to match the motor stick thickness) instead of 1/4×1/16″. I snipped them with scissors since I made the part from scratch. I could have fractured the wood. Laser cutting might be better here.

What I really like about the taping system is the wing doesn’t shift. The plane stays in trim better.

Perhaps the answer is to go to 1/8th Square here. It’s might be strong enough but I need to make sure we don’t start breaking the wing leading edge or something else. Another thing that has come to mind is to split the tape so that the tape will fail. This would be interesting for kids since the make an extra step to cut the tape thinner but learn about the trade-off of the different fail modes that come forward.

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Dayton Prototype

Experimental, Gallery

I sat down at the lab last night and made a Dayton from a printed template.

I added a set of wheels from one of my wheel experiments. They’re pretty light and I think I may have it figured out how to make them efficiently.

I used an alternate wing. Built it all flat like a Squirrel and then capped the four joints. This gave a bit more area for the winglets to attach. This worked well. I need to figure out if it’s easier for people to do than the earlier embodiment which rotates the wing tips so they are vertical. The wing joints are very stable this way.

We were able to get it to take off in the hallway.  This is a stressful environment for a model plane as it’s guaranteed to get some wall and ceiling strikes. We managed to bring forward two failures. I’ll report on that shortly.

Having all the wing control surfaces is a real joy. You can tweak the flight path very easy. I can see how this could be a hit with kids as it gives them something to think about.

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Squirrel with Wheels

Experimental, Gallery, Outreach

Last night we had a gathering at the lab. Celina made a Squirrel from a kit that I had previously dropped off at her house.

I made her up some wheels out of some music wire and some wheels that were given to me by Lloyd Shales (airplane designer).

We got it to take off in the hallway. Wheels are pretty fun for indoor. There was constrained space as the larger rooms in the building all had activities in them. So the wheels make for lots of fun with just a hallway.

Some video will come forward as soon as I get through my camera video.

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Wheels on rubber band planes

Experimental,

It’s fun to put wheels on a rubber band plane. Commercial ones are heavy so interfere with your airplane.

Traditionally people make them from balsa. This is a little tricky.

One method I used in the past is to glue two sheets of balsa together cross grain. Then rough cut out a wheel and glue in a piece of brass as the hub. Mount the hub in a drill chuck and turn it with sandpaper. I’ve used a wood doweling in place of the brass. That works well too. You just slice off and drill it out to match the wire.

In these pictures you can some of the wheels that Lloyd Shales has shared with me. They are laser cut balsa and use brass tubing. This is much easier than making them entirely by hand.

He uses a jig for bending the wire.

I’ve been studying this problem as well. Here’s what I’m doing. I’ve got paper ones that work pretty well. Much lighter than plastic. I’m using some beads as the bearing as well. This is light and inexpensive.

I’m looking at methods of bending the wire too. A CNC wire bender has been in the works but I’m not satisfied that it’s needed yet. I’m still coming up with some alternate bending patterns.

I think both these wheel making methods are nice. I added both Lloyd’s and my wheel samples to my portable lab so I can start testing them and having some fun.

I just boxed up two shipments of wheels to go to two locations in India for testing. If you’d like to test them be sure to send me a note while I’m still working on this.

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