Thursday, August 17, 2017

Towel Revival (2016)

My first Towel RC airplane flew many good years. It was a great introduction to flying, though I later found out by comparison with other planes that it was actually not such an easy plane to fly. It was relatively stable, yes, but the control surfaces weren't that authoritative; it didn't have enough power to get itself out of a jam, and it pretty much always flew at high alpha, which made it tricky in the wind. Moreover, my lack of proper control horns and pushrods made it imprecise.

Despite these flaws I still very much enjoyed that plane, and when the body gave out from excessive wear I decided to build a new one with slightly upgraded hardware. Here's what the plane looked like after quite a few outings:

All banged up after a few years of flying. Time to retire!

The nose was pretty much crushed, repaired many times over.
I had eventually reinforced the leading edges with dowels to make it a bit more robust, though I was wary of this modification because it made the plane a bit more dangerous for passersby. I made sure never to fly it anywhere near unsuspecting people.

For the rebuild, other than improving on the pushrod/control horn situation, I wanted to change the nose shape to make it much more sturdy while also doubling as a decent platform for FPV. I was also hoping to change the overall look to something a bit more stylish. I was partly inspired by the magazine cover that got me into RC to begin with:

The picture that inspired me to go through all this trouble!
And I drew up the following in Sketchup:
Sketch of the new model.

Underside sketch.
As you can see, the plane now has skids as well. I wanted to keep a bit of space on the underside for some future bomb drops. Also, once I added the massive bumpers to the front (which I altered when building the plane), I had to add skids to keep the plane horizontal when it was on the ground. Plus... well, I just liked the style. :-)

I got to building.
Making one super-sheet of foam.

Cutting out a rough shape.

Moving along.

Side-by-side with the original Towel.

Starting to put the electronics on deck.

Close-up of the new bumper design, which does not stick out from the body.

Underside of the plane; the bumpers stretch much further back.

Finished topside.
Notice the proper control horns, pushrods, and linkages in the above picture. They made a huge difference in precision when compared to the dowel and nail setup in the original plane.

Finished underside.

Sitting on the table of a rented cottage, before an outing with the Tiny Trainer.
The plane really turned out great! The flight dynamics are similar to the original Towel, though the control precision is much improved by the new hardware, and the nose is virtually indestructible. I don't crash as much as I used to when I started out, but I've had a few downright terrible nosedives right into hardpack soil because of interference with a cell phone tower, and the plane barely has any scratches to show for it. I've put a RunCam 2 between the bumpers, and the plane flies quite well, with nothing to obstruct the view (unlike on the Tiny Trainer). "Great success!"

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