• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.

Experimental Weed Eater Craft

#1
Hi,

I have been thinking about doing a project on stripping down a weed eater for the engine and attaching it to a homemade plane of some sorts. I have seen videos of people doing it and thought it would be a much cheaper alternative than buying a brand new engine/plane combo. Has anyone ever had any experience with doing this? I have had trouble finding plans at all online for wood planes. I was also thinking about making it out of that thick foam from Lowe's and poly-coat it. I am no expert at flying electric planes but have flown the FT Bloody Wonder so this is just not my area of expertise.
My main motive for this is to get some experience with gas driven models because I am interested in full size airplanes for college. I just figured that I would run this by anybody that might have a clue as to how I should go about this. I am up for the challenge and have been wanting a good project to start on this winter. I will get specs on the weed eater when I find it and post them but other wise the I am open to any and all suggestions, ya know, within the budget of a high school student ;)

Thanks, Dave
 

Snarls

Gravity Tester
Mentor
#2
I'm not gonna lie, but by the title I thought you were proposing an aircraft that would trim the weeds for you. To be powered by a weed eater is another story. I have no experience with gas models, but from seeing a weed eater engine it sounds like your going to have to build something fairly large. Sorry that's all I got for now. Good luck!
 
#4
Plenty of examples of low cost models we've built for conversions can be found in the large plane section of spadworld.net

With a little practice you can build light aerobatic sport planes that are resilient and inexpensive. Anything from basic trainers to sport models and even 1/5 stand-off scale birds have been built. Here's one of my favorites, a 13# sport bird using a 10 yr old 25cc homelite.


Good Luck!

P.S. The ultra spadstick is a neat plane but is a dated design. They are hard to build stock and light. They actually work better with a 45cc chainsaw engine than the original 31cc Ryobi.
 
#10
Rovers, that plane looks like a neat one, thanks!

Monkey, I'll have take a look through those when I have time to. I have an older chainsaw too if nothing else, which was the original plan anyways, thanks!

Ram, an interesting article, definitely some good tips to use. Speaking of new episodes, I thought it might be cool if the guys did an introductory series into fueled planes, just putting that out there...

Pgerts, if I poly-coated a big FT plane like that the weight might not matter as much since it is gas anyways.

Another question though, how big of a prop would something like this swing?
 
#12
There is a whole section of RCU dedicated to engine conversions
http://www.rcuniverse.com/forum/engine-conversions-92/

While I buy parts for more powerful converted engines, it is possible to make your won parts for smaller 18-25cc engine conversions from a few dollars in hardware from a good store, not depot.

I run a 16x8 on converted 25cc string trimmer engines, an 18x8 on a converted 33cc homelite chainsaw engine and I have a 20x8 and a 22x8 to try on my Homie 45cc but I haven't done the 45cc yet. Read the forums as swapping out the carburetor is critical but you don't want to go too big or it will run worse.

The 33cc engine is on a scratch built 1/5 scale FW-190 that I have been building off and on for... forever... LOL
 
#13
Thank you guys very much for all the info, this project is probably going to get moving more when my basketball season ends so I will post updates when I can. Thanks again!
 
#15
I built a plane years ago using give away yard sticks, most of you wont remember when hard ware stores gave away cheap yard sticks that were made from some light weight wood, anyway I built a basic plane kind of like a cub with a 7' wing span I was going to use a weed eater motor on but I never finished it. I wish I had pictures of it, it was a monster. I have a leaf blower that the fuel tank crapped out,, how about a ducted fan about a 12"-18" in diameter with wings on the side so it looks like a big fish?

Casey
 
#16
I pulled my leaf blower apart, Turns out its a 25cc Homelite 2 stroke motor, I took it apart and cleaned it up. I am going to modify for RC use and build a plane for it later. any body know how the aluminum connecting rod stands up to RC use? I am not going to do any thing crazy to it, it will be pretty much stock, I am going to make a filler piece for the crankcase to reduce the volume of the crankcase. I cut off most of the flange that was used to bolt it to the fan housing of the leaf blower, I left the one mounting holes on the flange to mount a bell crank for the throttle. How big of a prop do you think it will spin in stock form? I dont want to abuse it to much running it at red line. I was thinking about using the stock muffler but it is pretty heavy, any body make any thing for it? I was think making a cone type expansion chamber pipe for it but it would probably too heavy too.

IMGP3760.JPG IMGP3761.JPG

Casey
 
#17
I bought a new honda gx35 4 stroke to build into a helicopter, I haven't finished the heli yet but I did get quite far with it before I started somthing else (attention span of a fish).

The power band is very small on these engines, you have to make sure you get the sweet spot.

Oil in the engine is a problem, the 4 stroke I got will run upside down all day long but a lot of others starve the engine of oil if turned upside down, make sure your engine runs any way up.

The carb will need some consideration but most swap them out, you can use the standard one depending which engine you use but be aware a lot don't give the responce or performance you need.

The clutch and flywheel are incredibly heavy in comparison to the rest of the engine, if you're going direct drive and using a prop you will be ok loosing all that, for me with a heli that presented more issues.

Weight is your enemy they are very heavy engines, everything unimportant can be stripped from them until you're left with the bare essentials but you're still looking at a very heavy front end.

The exhaust system needs replacing with somthing tuned but it also makes them a bit louder.

The article I found most helpful was this one http://www.rc-network.de/magazin/artikel_08/art_08-033/art_033-01.html Google will translate it for you. Back when I started my project around 10-15 years ago, I couldn't find much info on the subject.

If I get some time I'll find out some pics of my project if you want.