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Mar 12, 2018, 07:42 PM
Registered User
agfrag's Avatar
Thanks rotagen. Great info...

Well, I went to my local hobby store and picked up a new motor, an E-Flite Park 300 brushless outrunner, 1380Kv, and an EP7060 prop. I added an 8 inch section of horizontal wing to spread the booms out to accommodate the 7 inch prop, and just attached my two 15 inch wings to it, so now I have about 5.7oz/sq ft wing loading with a 650mah 2S battery.

My CG is a little aft of where I'd like it, about 33%, but I can move the 650ma 2S battery around, or use my 1300mah 2S battery and get a wing loading of 6.73
with a CG at 25%.

We'll se how it flies hopefully tomorrow. It's all held together with tape and rubber bands right now, and it'll probably disintegrate on it's first landing, but what the heck, it's a prototype!

I'll be checking out the Pontiac area Ultimate Soccer Arena indoor fly tomorrow (sponsored by Skymasters RC of Michigan) and see how it goes!
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Mar 12, 2018, 08:28 PM
Scratch building addict
rotagen's Avatar
Nice looking plane and the undercamber should make it real floaty. It's probably the pic angle but the v-tail looks a little "flat", which will make it more of an elevator than a vertical....normally you want something near 45 degrees but there's a decent usable range, again probably pic angle. If that is a problem you will find turns are very slow, no biggie if you have area.

With that kv motor and prop a light 3S battery would be more suitable so if you find it underpowered try that... since you can't go up on prop size probably. You're probably fine where you are and it will be super light. cool stuff!
Mar 12, 2018, 08:29 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by agfrag
Thanks rotagen. Great info...

Well, I went to my local hobby store and picked up a new motor, an E-Flite Park 300 brushless outrunner, 1380Kv, and an EP7060 prop. I added an 8 inch section of horizontal wing to spread the booms out to accommodate the 7 inch prop, and just attached my two 15 inch wings to it, so now I have about 5.7oz/sq ft wing loading with a 650mah 2S battery.

My CG is a little aft of where I'd like it, about 33%, but I can move the 650ma 2S battery around, or use my 1300mah 2S battery and get a wing loading of 6.73
with a CG at 25%.

We'll se how it flies hopefully tomorrow. It's all held together with tape and rubber bands right now, and it'll probably disintegrate on it's first landing, but what the heck, it's a prototype!

I'll be checking out the Pontiac area Ultimate Soccer Arena indoor fly tomorrow (sponsored by Skymasters RC of Michigan) and see how it goes!
Looks good !

Definitely get the CG right before you fly it , it's better to err nose-heavy than tail-heavy .

Video if possible !
Mar 12, 2018, 08:43 PM
Scratch building addict
rotagen's Avatar
FYI here's what I use to determine prop size , battery voltage and motor KV for my models. Found it somewhere years ago online.

It works for me. Of course there is some leeway either side.

I did some sample calcs down below, I think they're right but double-check them.
Mar 12, 2018, 09:32 PM
Registered User
agfrag's Avatar
Rotagen, you are correct about the flatness, no optical illusion... It's actually a 110deg V, but the booms aren't glued to the wing mounting plate yet, just taped with very little tape... so when I put it on the floor, it flattened out a bit. Pick it up and it's 110deg.

And I'll check out the file, cool.

boc, yup, I seem to remember some past experiences, actually, that is the only reason I put wheels on it, such that I could do a couple takeoff runs just to see where to put the batt for level flight, vs. tossing it in the air and watching it nosedive, or whatever. I plan to bring plenty of tape, rubber bands, and CA!
Mar 13, 2018, 02:14 PM
Registered User
agfrag's Avatar
It flew! Unbelievable!

Thanks to some help from Springer, my taped and rubberbanded FFF actually flew! Springer used my phone to get this short vid, I think the lens was a bit dirty...

It took a few tries... the CG seemed ok, but at first the rates seemed extreme, but that may have been my inexperience. I popped a horn free once and crashed a bit, but right before this vid I got about 3 circuits around the field in.

It flies very nice and slow, not walking speed, but slow enough for indoor flight. I think I got about 7 mins on the 650ma 2S battery, but I was doing some crazy flying too.

Now I'll concentrate on actually gluing the bits together, and we'll see how it flies next time!

Thanks all!

Vtail Maiden flight (0 min 40 sec)
Mar 13, 2018, 02:52 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by agfrag
It flew! Unbelievable!

Thanks to some help from Springer, my taped and rubberbanded FFF actually flew! Springer used my phone to get this short vid, I think the lens was a bit dirty...

It took a few tries... the CG seemed ok, but at first the rates seemed extreme, but that may have been my inexperience. I popped a horn free once and crashed a bit, but right before this vid I got about 3 circuits around the field in.

It flies very nice and slow, not walking speed, but slow enough for indoor flight. I think I got about 7 mins on the 650ma 2S battery, but I was doing some crazy flying too.

Now I'll concentrate on actually gluing the bits together, and we'll see how it flies next time!

Thanks all!

https://youtu.be/dI0WH3cSKSI
Just curious , is there a reason you chose v-tail over conventional rudder/elevator ?
Mar 13, 2018, 07:25 PM
treefinder
springer's Avatar
Yup, time to glue it all together now! It was great fun tinkering with it together! Time to figure out how to do expo on your tx. I am sure that about 30% expo will settle her down a lot. But when you hit the sweet part of the speed envelope, even with the touchy sticks, you were able to groove her. Gonna be a fun and quirky indoor flyer!
Mar 13, 2018, 07:52 PM
Registered User
agfrag's Avatar
BoC,
Quote:
Just curious , is there a reason you chose v-tail over conventional rudder/elevator ?
Just for fun really, I've always been attracted to the unconventional!

Springer... thanks for the great advice and especially for your time... yes, expo is a great idea, and I'll be setting that up soon... and looking forward to one of those sheet kits which I ordered as soon as I got home... the 34.5" SeaBee!
Mar 13, 2018, 08:06 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by agfrag
BoC,

Just for fun really, I've always been attracted to the unconventional!
I enjoy the fun , unconventional and silly stuff ..... that's what's great about scratch-building with cheap foam , you can do what you want !

This is probably my silliest plane ever , but it was sure fun to fly !



Big Wheel Delta take 2 (1 min 14 sec)
Mar 13, 2018, 08:13 PM
treefinder
springer's Avatar
Does the big wheel slowly rotate when flying? that would be cool if it did!
Mar 13, 2018, 08:13 PM
treefinder
springer's Avatar
34" SeaBee, Oh, oh, I better check what I have in stock!
Mar 13, 2018, 08:28 PM
A Day @ a Time - Matt. 6:25-34
ruff1's Avatar
ok the wheelie airplane makes something come to mind to throw out at you guys who build goofy stuff... anyone built a big wheel looking airplane, like the ones we had as a kid?
Mar 13, 2018, 08:34 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by springer
Does the big wheel slowly rotate when flying? that would be cool if it did!
I never looked for that or noticed . I just wanted to make a delta that could easily take-off from the grass at that park .... and it DID !
Mar 13, 2018, 08:38 PM
IMO ( In My Opinion ) →
balsa or carbon's Avatar
Quote:
Originally Posted by ruff1
ok the wheelie airplane makes something come to mind to throw out at you guys who build goofy stuff... anyone built a big wheel looking airplane, like the ones we had as a kid?
Try it , and show us when you're done !


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