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[Idea] - Styrene Glider Modification Answered

I propose a modification of easily obtainable Styrofoam glider's allowing longer airtime VIA a small electric motor. To be successful, the modification must be light weight, cost effective and use minimal tools so smaller children (I think of myself as a big kid) can repeat.

Before you go off on me for this not being an instructable - read this: https://www.instructables.com/id/EYD12YXN3XEP2873DL/ -- I'm going to try and breathe some life into the idea :P

I'm thinking I'll find a personal fan (might be hard considering it's winter time :P) and start there. If I recall, those fans are directly driven and use one or 2 1.5v batteries. I think it can handle reverse polarity at 9v.

I'll bore out a hole in the nosecone for the motor and hot glue it in place. If possible, I will place the 9v battery aft of the wings -- attempting to preserve the center of gravity.

In the video below, when my buddy says "Test 2" that is the second test using his glider (after the fuselage cracked off on a hard impact). His wingspan was 12 inches shorter, and his glider was heavier. The video was recorded with an ATC 1000 helmet camera*** and hastily thrown together.

*** I lost some footage -- on some impacts, the camera "froze" and the video did not save. I had to pull the batteries to get it going again. I suspect the memory card got jarred and the camera didn't know what to do with it. Or, something completely different. This only happened 3 times even though the "test 2" portion of the video was a vertical impact.

Suggestions and Feedback welcome :)


So here's an update.

It has been quite windy the past week here in O-town. We decided we'd try and do some loops with the plane. We were successful - so the next step was with the camera. We were 3/4 successful and then it landed in a 20'+ high palm tree.

After getting one of our back packs stuck in the tree (from throwing it) - we threw a skateboard at the center of the fuselage (to get the camera back). Half the plane is still stuck up there an the other half was given a viking funeral. I'll have a video tonight, there's a pretty cool view of the sun that I wasn't expecting :P

I have acquired another identical plane, a small version of it and four A10-PT Estes model Rockets.
A10 gives 13 Newtons (2.9lbs) of thrust for .8 seconds
P means it is plugged (no parachute discharge)
T means its a mini engine size

Quick calculations assuming 1/2 pound mass -- we get an acceleration of 5.8 g's (~57 meters per second squared). I'm going to have to reinforce/make permanent the wing-fuselage connection with epoxy :P I have also come up with a method to launch using straws and wire coat hangers - perhaps I can figure out a way to do a vertical launch with a curve to horizontal (just for fun :P).

I honestly don't know why I'm doing this - but it seems to be the next step in foam glider modification :) Perhaps I should start some sort of local bad ideas competition :P

Model rocket engines and a dry field got me in a lot of trouble a long while ago. Make sure your grassy landing field has been watered recently!

So when are you going to redesign the wing for greater lift :-P.

I like the rocket powered take off idea, just like some military cargo airplanes to help them get off of short runways. You probably know this, but it's one of my pet peeves so I'll say it anyway: Pound is a force unit, not a mass unit. The mass unit in the English system is the slug (pound-mass is a stupid unit and I hate it).

Yeah, I know :P Kg mass/force bother me too. That was just laziness on my part (not wanting to do more conversion :P) and I'm not sure how many people have even heard of a slug (I never heard of it until I took physics :/).

As an aside on the ATC. Twice now I have connected mine a kite while I kitesurf and both times it never saved the video. When it runs out of battery power it forgets to close the active file and corrupts it.

Have you tried using lithium batteries? I know they're more expensive, but I've recorded well over an hour (probably more than 2) on one set. Plus they have the added benefit of lower weight :) I know for sure it's not the battery causing my video loss - the camera stays on the whole time (just locked up). However, I did notice that it created a 0k video file.

I haven't tried lithium. Will check that out next time.

Sharp impacts also seem to disrupt the camera. Maybe the batteries are momentarily disconnected like in Dan's GPS?

Does your camera shut off on impacts? Mine just locks up - but still on. I can see the last second it got to - but I can't end the video (and thus save) or shut the camera off... I have to remove the batteries completely to restart the camera and start recording again. I just noticed that Oregon Scientific recently released the ATC 2000 and it's fully waterproof - I wonder if they fixed some of these "bugs" (such as saving the file before shutting off)...

Yeah, that's exactly what mine does. The file is actually there, but I just think it's not closed and so impossible to read. The ATC 2000 does look nice. I'm sure we'll end up with a few them around the lab here.

Yeah, you definitely need to add some weight at the aft of the airplane. To do a quick calculation, sum the moments of the motor and the ballast about the quarter chord of the wing at the root. That is, the spot that's 1/4 distance from the leading edge to the trailing edge placed from the leading edge. By keeping the added weight in equllibrium you should be able to have an aircraft about as stable as the original. Aside as to why you want to do this: the main wing generates a nose up pitching moment so the tailplane is set up to produce a nose down moment about the center of pressure. (This way both the main wing and tailplane produce positive lift). When you add the weight to the front you're producing another nose down moment and adding weight in the back produces a nose up moment and when they balance the airplane is stable again. You could achieve similar results by changing the angle down on the tail plane to produce a nose up moment.

That's good information to know (the 1/4 distance thing). I was planning on figuring out exactly where the CG was and then doing a best attempt to match the original specs. I also tried to put the camera just above the CG - but that was kinda hard because the wing was in the way of the mounting strap :P I think it worked pretty well (as per video :P).

You can almost always drive DC motors way above their rated voltage for limited periods of time. Grab a couple of lithium batteries (from used cell phones maybe?) and overpower whatever motor you can find. Something from a small electric screw driver might be a good choice.

exceeding the current rating on lithium batteries can cause spectacular events, in the form of a lithium fire, so be careful. BTW The RC Universe forums have tons of great info, I used their advice to make a plane out of a zip zap racer and sheet foam, called the BUMP. tons of fun.

Dr. No

11 years ago

I had a foam airplae about eight inches long a few years ago with a small electric engine in it. It used an external battery pack to get the propeller spinning and it must have had wieghts imbeded into the end of the blades because it kept spinning for over a minute.

Probably had a flywheel or something. Was it an airhogs plane?

I think so, but I coud be wrong.


11 years ago

This is a great idea for a project, but something that I've never done.

I've tried an awful lot of foam gliders, and the one that you show here is one of the nicest types, with the cool little wing locks. It looks like a Lifoam Sky Rider (Part number LXLFF6, $7. from towerhobbies.com ).

It seems that a lot of these (this one included) are really designed to be modded into "free flight" powered aircraft, and I've also seen some conversions to full-on RC, but that seems a little silly to me. Take a look at some of these projects:

Yeah! The guy at the hobby shop said that people do full RC setups on these things. I'm going to watch for a suitable motor and prop :)