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FT What Did You Do RC Today : Caution Offtopic At All Times

Tried flying my 5 and 3 inch quads yesterday. The 5 inch was fine, had fun chasing seagulls off the rugby pitch. The 3 inch however was strongly affected by the strong winds and the camera was absolutely awful. A complete muddy mess of a picture. Going to have to change that out for a decent unit before I attempt flying it again.
 

L Edge

Well-known member
Thanks! But this one is a pattern plane so it does fast smooth lines. I will try to get the best footage I can on Friday next week.
Next, you will want a tuned pipe and then retracts. Only bad feature is they burn nitro fuel. Decked out, they average about 95 mph as they cruize thru the manuvers. Coolest I seen was a contestant that could slow his bird to almost a stall, do a snap 360 roll precisely and then speed up like it was on a rail. Always got a 9 or 10 for that one.
 

L Edge

Well-known member
I did a little test today. I have heard the statement once or twice that the more blades a prop has, the less efficient and more of a power hog it is for diminishing returns on thrust. I did some research and found the claim to be true, but with a couple stipulations: besides when they are used for space and clearance concerns, three blade props are used on some trainers(both RC and full scale) because the inefficiency gives them excess thrust at slower speeds, so the plane will have a better speed envelope, better acceleration and punch out(and as I theorized and tested, better high alpha). The battery just might burn out a couple minutes earlier. It's a trade-off.

I tested my V Sliver with 5x5.4.5x2 compared to the normal 5x5.5x3. I needed to power up to full throttle and give a slight shove for a pretty anemic launch, when with the three blade, I'd crank it up to like 75 or 80 and just let go, and it would rocket off. It had garbage punch out, and couldn't do high alpha worth squat. The test would have been better with one of those 5x5.5x2 race props you can get at Graupner USA. I believe this would have made launches better and gave it a bit more punch out and overall thrust, but I bet there would still be some lag and high alpha would still be mediocre. I could be wrong, I may order a couple 5.5x5x2 and see.

All I'm saying is, the statement about prop efficiency is 100% accurate, but when a newb reads somebody say that, there's a danger of "cargo culting" the idea and going "well then three blade props suck then and I guess there's no situation in which I'd want to use one".
Additional point, a 3 bladed prop requires a faster landing speed.
 

Vimana89

Well-known member
Additional point, a 3 bladed prop requires a faster landing speed.
I see what you mean for a lot of planes, good point👍. The one I use the three blade on can do a super short flop landing at ridiculous low speeds high aoa so I don't really notice the higher landing speed thing. I guess I cheat it, or it just could be said that my design specifically benefits from the three blade and negates some of its downsides. My batteries don't last super long, but a little 650 3s battery on that 1900KV 2806 still runs about 6 minutes of high performance flight, and I bring two when I fly. Not terrible economics when they charge fast and your field is right across the street.
 

L Edge

Well-known member
Tried flying my 5 and 3 inch quads yesterday. The 5 inch was fine, had fun chasing seagulls off the rugby pitch. The 3 inch however was strongly affected by the strong winds and the camera was absolutely awful. A complete muddy mess of a picture. Going to have to change that out for a decent unit before I attempt flying it again.
What happened to the EDF?
 

SquirrelTail

Well-known member
Next, you will want a tuned pipe and then retracts. Only bad feature is they burn nitro fuel. Decked out, they average about 95 mph as they cruize thru the manuvers. Coolest I seen was a contestant that could slow his bird to almost a stall, do a snap 360 roll precisely and then speed up like it was on a rail. Always got a 9 or 10 for that one.
This one was free and setup beautifully and we only know of one other out there....
 

mrjdstewart

Well-known member
we have had 3 mid air impacts at the club the last 3 weeks. what are the odds?

i started it off 2 weeks ago by taking out another members UMX Timber with my TH Corsair. the next week another micro was hit, a UMX B-25, then this saturday a glider wacked a flying wing.

i agreed to try and fix the Timber i hit, and was given the B-25 to attempt to save.

the Timber is all but done. new wing, lot's of glue, but doesn't looks half bad. this UMX stuff is a pain to work with, remind me never to buy one...

20190825_152619.jpg

the B-25 is almost done. problem is when the wing was hit the aileron link and wire was lost. i need to bend some new wire and somehow figure out how to make something to hook it to servo wire. normally i would just design and 3D print it but this piece is so small i don't think that will work.

20190825_171653.jpg

from the undamaged side you can see the problem...i can bend the wire that is missing off the aileron, it's the little white plastic thing that i need to fudge.

20190825_171914.jpg

thoughts, suggestions?

me :cool:
 
we have had 3 mid air impacts at the club the last 3 weeks. what are the odds?

i started it off 2 weeks ago by taking out another members UMX Timber with my TH Corsair. the next week another micro was hit, a UMX B-25, then this saturday a glider wacked a flying wing.

i agreed to try and fix the Timber i hit, and was given the B-25 to attempt to save.

the Timber is all but done. new wing, lot's of glue, but doesn't looks half bad. this UMX stuff is a pain to work with, remind me never to buy one...

View attachment 140591

the B-25 is almost done. problem is when the wing was hit the aileron link and wire was lost. i need to bend some new wire and somehow figure out how to make something to hook it to servo wire. normally i would just design and 3D print it but this piece is so small i don't think that will work.

View attachment 140592

from the undamaged side you can see the problem...i can bend the wire that is missing off the aileron, it's the little white plastic thing that i need to fudge.

View attachment 140593

thoughts, suggestions?

me :cool:
Maybe try bending a little piece of gift card material?