Archive for the ‘3. RC airplanes’ Category

Giant Scale Seaplane

Saturday, September 22nd, 2007


I already have a build thread going on RC Canada so I figured I would just post a link to the build thread. This airplane is a work in progress, it is in the condition it is in these pictures – not done. Don’t let the pink foam fool you – it will be fiberglass’ed and painted when its done.

To introduce the idea of this airplane Ill start off by saying this one is a MONSTER. I have a 2 cycle leaf blower engine that I converted to an RC airplane engine. So that’s the basis for the airplane size.

The wing span is 10′, that’s 120″. Yep. Big.

The title of the build thread is “Giant Trainer”. Don’t let that fool you. It is designed to be a docile, easy flying airplane, yes. However, the construction and the size of the airplane are anything but a trainer.

Check out this link for more information: http://www.rccanada.ca/bb/viewtopic.php?t=23284&highlight=giant+trainer

3D Foamie Fun-Fly Airplane

Saturday, September 22nd, 2007


I have a build thread going on RC Groups, so I figured I would just send a link to that since I already have so much written.

First, an introduction to this airplane. This is a 3D airplane. 3D is a category of aerobatics in RC flying. There is no such thing as 3D in real airplanes, that I am aware of. If you attempt to do high-G 3D aerobatics in a real airplane you will die, and likely snap the wings off. Some maneuvers are the most extreme, stressful, high-G aerobatics you can imagine. On the other hand, 3D can be the slowest “flying” (technically, you are no longer flying – the fixed wing is no longer generating lift – the airplane stays in the air from the power of the engine/prop) in an airplane – down to not moving at all. Loops, rolls, 90+deg turns, hovering (on the prop like a helicopter) are all part of the package – some of those may seem elementary, but if you add in the power and 3D variations of those it gets pretty crazy. One of the neatest ones I like to do is a “harrier”. You can’t do this with a “normal” airplane. If you do it with a “normal” airplane what makes it “abnormal” is the wing loading – it must be very light, the airplane must be correctly balanced (tail heavy – which poses a snapping problem), flight characteristics of the wing design (back to the snapping problem – some wing designs are more forgiving than others) and you need to have a LOT of power – 1.5x, or more, power than a similar size sport/aerobatic airplane. Normal sport/aerobatic airplanes are built for efficiency and control while moving – little drag and good size control surfaces. Most airplanes don’t have a lot of power to utilize. 3D airplanes typically have 1.5 times the power on the same size airframe as a regular sport airplane. The reason “normal” airplanes can’t do 3D is you are letting the airplane fall in a controlled stall – nose up at about 30deg (the angle of decent determines how much forward movement you have – the greater the angle the less forward movement). The big fat wing of my airplane has extremely gentle stall characteristics. Combined with the LARGE control surfaces and short fuselage I can maintain a stall and descend in a controlled environment. A “harrier” is also the general entrance maneuver to hovering on the prop – the airplane’s forward airspeed is already near 0 and there is no lift

Mine is made of foam insulation. Why? Because its inexpensive, easy to repair, and is easy to build with. To make a wing you use a Hotwire cutter (exactly what the name says – you pass electricity through a wire under tension and it cuts the foam like a hot knife through butter).

Check out the thread for more information: http://www.rcgroups.com/forums/showthread.php?t=551484

Edit: 10/22/07

I just re-built the front end and got the airplane back together for the most part. There are a few details that need to be attended to but is mostly ready to go. The engine started right up. I flipped the prop a few times getting new fuel through the engine and it fired up on 3 flips. Not bad for an engine that’s been sitting for a year.

Ill update this again when I get a chance to fly it. Hopefully I can fly it somewhere where I won’t hit anything landing (check my build thread in the RCGroups link for info on the last flight).