All posts by Darcy

Dayton and Squirrel-0-Rama

Last night we had a great meetup. We made and flew Squirrels and two Daytons.

People made the Squirrels from memory. Enough people know how to make them so that’s a good sign.

The Dayton went together very well (and fast). Here is my assessment.

  • The wing had better rigidity than I expected!
  • I flies well with flaps down. I think I will split the aileron into flaps and aileron so people can learn to experiment with that. I’ve done some test since the meetup and it is a great slow flyer.
  • We flew it without trimming. It had a phugoid but I will do some more experiments next time.
  • The paper proves to be light enough.
  • Wheels add a lot of charisma.
  • A few of the laser cuts were the wrong dimensions. Still worked well but I will tweak that stuff for the next run.
  • The assembly and flight are working well enough. After some tweeking to the laser files and the printout, I will attempt a double sided print and do a larger batch for the next revision. In the next build I will make five at once so we can study the flight characteristics further.

Portable Model Airplane Lab

I have a small lab I’ve been keeping in my briefcase. But since the Dayton I’ve been doing more experiments on the road. So I’ve been carrying a bankers box. This is hugely inconvenient.

I found a great way of making it much easier. I added a timing belt as a handle. As you can see in the pictures it can be carried with one hand. Any box used to carry model planes can be improved in this way. Of course string works. But the timing belt doesn’t tangle, can stay in place during usage without getting in the way and is thicker so it doesn’t cut into your hand.

Also, these bankers boxes are not that robust. But you can easily fix them by gluing cardboard to them. For instance this one has a 1″ strip of cardboard glued to the box handles and a 2″ strip glued to the sides around the top.

Part Labeling for Dayton Kit

One design choice made with the Squirrel was that all the parts can be the same width (easy manual fabrication) and many of the parts are the same (easy differentiation). For instance the Wing Center Rib, two Wing Tips, two Winglet Spars and Fin Spar are all exactly the same size.

The Dayton will have a different audience and purpose so I’m working with a different set of design parameters. Part sameness does not seem to be coming forward. So we need a way of identifying the parts. I am going to burn labels onto the parts for the next few runs of the Dayton prototypes. Initially I’ll raster out print type fonts but I’ll eventually switch to vector stick fonts to speed up the fabrication process.

I just cut out a couple of Daytons and will try and get them tested today. As things stand it will be around 7pm (Sunday, September 16th, 2012) so anybody wanting to come and try one let me know!

Paper Dayton Experiment

I’ve been trying to avoid having a paper wing since it might be heavier and more costly than tissue.

But the wing framing onto tissue paper is trickier with interlocking parts.

But I think I found an alternate way of getting the wing structure to work and fix this issue of interlocking parts.

In a nutshell the leading and trailing edge only run most of the way out to the wing tips. They are short by about an inch. There is also no wing tip ribs! There’s a little less wood so the weight penalty may not be there. Also the aileron and winglet glue seams are dropped.

I’m going to get to one of the labs and cut out another laser design and print this template.

I think this will be interesting. If there is rigidity issues I will look at a curved airfoil and see if I can find an easy way to use that to make the wing better.