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Jan 23, 2020, 09:37 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by Topher01

Yes it is the 1300kv one that I have thx! So just stay below 400g auw as a general rule with that motor?
It all depends on the performance you want : it's possible a heavier plane will barely stay in the air , and it's possible a lighter plane could have unlimited vertical .
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Jan 24, 2020, 07:04 AM
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Thread OP
LOL I’m glad I made my test stand. At least I can calculate thrust ratio accurately during the build so I can hopefully avoid building a turd
Jan 24, 2020, 12:42 PM
pull up -- PULL UP!!!
I built a crude but effective static thrust stand too. I like it a lot for matching props to motor to esc. But keep in mind thrust is only half the picture. Very relevant to ease of launch and 3D vertical maneuvers and such.

But airspeed is a function not of thrust but rpm and prop pitch vs drag. So need to consider both. It's not unusual for me to arrive at say an 8" prop on the test stand only to find the plane flies better with a 7" plus higher pitch.
Jan 24, 2020, 05:22 PM
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Thread OP
I see! That makes sense. At least this will get me in the ballpark and then I can refine or tune the combination I come up with on the bench until it flies perfect in real world conditions. I was thinking the other day that since the plane isn’t fixed in position when the motor/prop is pushing it the test really isn’t going to indicate real world but more like a worst case scenario since the motor/prop are pushing against a fixed surface with a constant load.

I flew some today. The wind won’t quit here lately it’s been 11-12mph every day here. The big problem for me is that it’s constantly coming and going like 0-11 and my trees are creating a bunch of dirty air. I’m going to put a video together. I’m not sure if there will be a ton left because I’ll have to cut out some cuss words lol
Jan 24, 2020, 08:05 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
One way to look at propeller pitch ( the second number ) is like the gears in a car or motorcycle . Low pitch is like 1st gear , good for pulling at low speeds . Medium pitch is like 2nd or 3rd gear , doesn't pull as good at low speeds ..... but you get a little more top speed . High pitch is like 4th or 5th gear , very poor pulling power at low speeds .... but very good for higher speeds .
Jan 24, 2020, 08:19 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
And yes , there are VPP ( Variable Pitch Propeller ) systems available ..... you can even vary the pitch to the point where you'll have reverse thrust .
http://fancyfoam-com.3dcartstores.co...wall_p_71.html
Jan 25, 2020, 12:03 PM
Registered User
Thread OP
Thanks for all the info as usual gentlemen! The whole motor/prop/kv/amp theory is starting to make some sense to me finally! I can tell Rey has a much smaller throttle window or resolution to it now with the drone motor and prop. Im constantly managing the throttle vs how it was before where you could kind of stick it somewhere and only adjust for large changes in airspeed. I think I really just needed to feel the difference to understand. A before/after on the same airframe sure did it! I flew Rey around the back yard this morning to see if she still had similar slow speed flight characteristics and was pleased to see she does! Enjoy the video!

Updated Rey (New motor/prop) and Arrow Trainer RET plane flights!! (11 min 44 sec)
Jan 25, 2020, 06:22 PM
Aeronautical Research Flyer
Rhea's Avatar
It's been fun following the discussion you three have had over the last month and a half. It has been especially fun to see how you have gone from questions to flying skills and knowledge beyond any beginner.
The only thing I don't like is to see you in shorts and to see liquid water in the pool. .
We have slush and snow up here but I am hopeful that we can join you in the air sometime soon. .
Keep up your experiments and learning now and in the future.
Jan 26, 2020, 02:28 PM
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Thread OP
Thanks Rhea! You guys have all been great! Thanks so much for sharing your knowledge with me and helping me grow in the hobby!! I have about a week ahead of me where I’ve got some thinking time on my hands. So I expect to have some great plans to start working on next week!! Should be pretty fun. I’ve come up with a couple pretty neat ideas that my feeble mind may attempt to pursue!! I went through the entire thread of 600 scratch built foamies this week so look out!!!! Ha!
Jan 26, 2020, 02:44 PM
pull up -- PULL UP!!!
Have you considered buying an inexpensive kit plane? It would give you a baseline to compare your scratchbuilts to. Perhaps a Value Hobby 32" EPP 3D plane. They're not for beginners, but I think you've graduated from that. Besides, they take a lot of abuse and repair easily. Another favorite of mine is the Quasar EPP 3D Delta from West Michigan Park Flyers. The plane is unbelievably agile and can even handle a bit of wind. Find some YouTube vids.
Jan 26, 2020, 03:22 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Many of us ( including myself ) fly both scratch built planes and store bought planes .... if you want to consider doing that .

I don't know if this appeals to you , but one aspect of scratch built planes is building silly planes ..... such as my Big Wheel Delta , which takes off and lands on grass very nicely :



Big Wheel Delta take 2 (1 min 14 sec)




I got the idea from Mike Haddad , who has made lots of silly planes : http://www.haddadrc.com/
And Otto Dieffenbach makes flying superheroes , Snoopy's dog house , etc : https://www.youtube.com/user/owd3/videos
Jan 27, 2020, 07:21 AM
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Thread OP
Hey guys! I’ve looked at several pnf type planes and they are pretty neat but I’m having a hard time with the cost associated with them. Especially when I’m building things that fly for $4-5 and there’s no stress if I loose one or wad one up. With a drone, it’s about $2-300 a pop for the drone the way I build them (fairly inexpensive) and obviously more for the GoPro if it’s on there. I think that the approachability of fixed wing has been one of the most appealing things for me so far.

However I have wondered a few times if my builds are mimicking airframes well or if perhaps a store bought plane may give me a benchmark to compare against.

I suppose the FT mini Mustang and the Spitfire are kits I have are fairly well engineered right? Like provided I put them together with no mods, they would be able to give me a good idea of what a plane should fly like?

I was looking at a pretty cool full fuse pnf edge 540... those things are awesome looking. I think I’ve seen a few of the 3D profile ones too but I think if I spent the money on a pnf or other kit I’d want one of the super realistic looking ones

I have seen some off the wall stuff that flies for sure. Lots on here ha! One build I have planned out will be another wing like Rey v1 but with twin engines. Turns out I had two of those little 1306 that spin the 3.5” prop I had initially used on Rey. I’m thinking if I change a couple dimensions on the airframe I can make it all work. I was going to do a triple v stab so the props were shrouded on either side and in the center and then fit each elevon in that gap behind each motor. I’d have to a bit wider for linkage room but I think it’s doable. Initially I had considered putting each prop in a tube and molding it into the airframe then putting the controls on the tube outlets but I think it would be too heavy?
Jan 27, 2020, 10:11 AM
pull up -- PULL UP!!!
I also would assume the FT models are properly designed but I have no experience with them. However the planes I recommended are very durable EPP and I think FT planes are poster-board? Big difference there.
Jan 27, 2020, 10:55 AM
Aeronautical Research Flyer
Rhea's Avatar
There are many options for kits available. You can either buy them or if you are looking for design ideas you can make something similar to any of them. These are a few that I have seen or that I have built from their kits:

http://lainesplanes.com/html/airplanes.html
http://www.racores.com/index.html
http://www.wmparkflyers.com/RC-Airplanes

You can see that they are all over the spectrum in their size, shape and build styles.
Have fun with whatever you do. .
Jan 27, 2020, 12:39 PM
B for Bruce
BMatthews's Avatar
Never mind the "flexible water" in the pool. I'm still working on the idea that each time you appear on the edge of your videos that you're in Tshirts and shorts ! ! ! !

For your question on what you are getting from these simple models to what you would get from a kit or other plane I'd say that the answer is a firm "it depends....". It depends on what skills you want to get from your flying. It depends on what style of flying you wish to do. For example you may want to switch over to more of a glider like model and learn the subtle art of thermal soaring. Very simple to fly the models which are like the perfect trainer. But forever deeply challenging as you learn to read the air's effect on your sailplane and as you get better to learn to work lighter and lighter lift until you can stay up when others find nothing and land.

Speaking of landings leads one to wondering about takeoffs. So far you've flown at home but have always hand launched and belly landed in the fairly tall grass. Control of the model during takeoffs and landings is a whole other flying skill. And there's also something satisfying about the level of precision related to touching down within a couple of feet of where you intend. So perhaps a home designed and constructed model with some big burly high floatation "tundra tires" that floats over the length of grass you have? Or mow yourself a takeoff strip? You'd want to check the wind direction and pick a place where the strip is as much as possible along the line of the most common wind direction. Or at least fairly close to that angle.


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