Exploring the Explorer

Sero

Elite member
It actually took some decent video for a knock off, is there a link?

FPV night flying, that's brave ;):D

Sorry, $60 camera :)

https://www.amazon.ca/dp/B07HP18CWC/ref=cm_sw_em_r_mt_dp_U_GKzoEb383JSQA

I’m going to be building a night flyer sometime before Flitefest, and I think Something no like @Sero did would really fit the ticket. I’d also like to put FPV on it as well.

I think this is more versatile than the Explorer, getting CG right is easier and I like having the option to put the camera on the back. Also the tail and wing of the Explorer is weaker IMO. Only thing I would have done different is I wish I would have extended the tail a couple of inches to reduce coupling. The plane would be less agile but track straight better.

But it's so fun!


That's pure awesome! I love your kids interactions!
 

BATTLEAXE

Legendary member
But it's so fun!

I had no idea night vision was an option for FPV, that's wicked. And the kids play by play, priceless. Go check the cows dad!
Sorry, $60 camera :)

https://www.amazon.ca/dp/B07HP18CWC/ref=cm_sw_em_r_mt_dp_U_GKzoEb383JSQA



I think this is more versatile than the Explorer, getting CG right is easier and I like having the option to put the camera on the back. Also the tail and wing of the Explorer is weaker IMO. Only thing I would have done different is I wish I would have extended the tail a couple of inches to reduce coupling. The plane would be less agile but track straight better.



That's pure awesome! I love your kids interactions!
Thanks for the link.

You should build a new version when this one caves, do the mods, see how it does
 

Sero

Elite member
If you want to see a difference you might be able to afford 3"

Possibly.
I ran some numbers based on some info that I previously collected. See attached.

The fuselage length should be 70% - 75% of the wing span:
70-75% of a 57" Explorer wing span is 40-42.75" fuse, my Bronco, 33".
7-10" difference.

The leading edge of the wing to the stabilizer should be 3 times the wing root chord:
Wing root cord of the Bronco is 7", 3 times would be 21", Bronco is 19.75.
1.25" difference

Distance from trailing edge of wing to leading edge of stabilizer should be 150-200% of wing cord:
Wing cord of 7" give me a distance gives me a spec of 10.5- 14". Distance on Bronco is 12.75"
Minus 2.25 to positive 1.25" difference.

So ya nothing really decisive there, going to have to research it more.
 

Attachments

  • RC plane Parameters.pdf
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  • Rules of thumb for plane design[1].pdf
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Last edited:

BATTLEAXE

Legendary member
Possibly.
I ran some numbers based on some info that I previously collected. See attached.

The fuselage length should be 70% - 75% of the wing span:
70-75% of a 57" Explorer wing span is 40-42.75" fuse, my Bronco, 33".
7-10" difference.

The leading edge of the wing to the stabilizer should be 3 times the wing root chord:
Wing root cord of the Bronco is 7", 3 times would be 21", Bronco is 19.75.
1.25" difference

Distance from trailing edge of wing to leading edge of stabilizer should be 150-200% of wing cord:
Wing cord of 7" give me a distance gives me a spec of 10.5- 14". Distance on Bronco is 12.75"
Minus 2.25 to positive 1.25" difference.

So ya nothing really decisive there, going to have to research it more.
These I think are just guidelines, not set in stone rules. Really the Explorer wing will be able to handle the weight of the airframe, then it just comes down to balance. The twin motor set up will give you the power when you need it. And its just FB so its easy to rebuild. If you get to much weight out the back to balance you then have to add weight, or weighted leverage to the front. It would be all referenced from the CG point. Say 3" added to the tail booms works out to be 15% added length from the CG to the end of the tail, theoretically you could add 15% length to the nacelles from the CG to the firewalls. That way you aren't adding much weight but using leverage to effectively maintain balance.

These guidelines kinda get fuzzy when you say take a plane like the Sportster which has a huge wing chord, over 9" on a short coupled plane, which still flies great. With a 9"+ wing chord you would think you could handle a 60" wingspan based on those guidelines. Now you have a Storch. So just keep in mind you have lots of wiggle room. I mean look at Vimana89's concoctions that still fly lol! And again it is just FB, if it doesn't work just make a new wing.
 

Sero

Elite member
These I think are just guidelines, not set in stone rules. Really the Explorer wing will be able to handle the weight of the airframe, then it just comes down to balance. The twin motor set up will give you the power when you need it. And its just FB so its easy to rebuild. If you get to much weight out the back to balance you then have to add weight, or weighted leverage to the front. It would be all referenced from the CG point. Say 3" added to the tail booms works out to be 15% added length from the CG to the end of the tail, theoretically you could add 15% length to the nacelles from the CG to the firewalls. That way you aren't adding much weight but using leverage to effectively maintain balance.

These guidelines kinda get fuzzy when you say take a plane like the Sportster which has a huge wing chord, over 9" on a short coupled plane, which still flies great. With a 9"+ wing chord you would think you could handle a 60" wingspan based on those guidelines. Now you have a Storch. So just keep in mind you have lots of wiggle room. I mean look at Vimana89's concoctions that still fly lol! And again it is just FB, if it doesn't work just make a new wing.

Oh for sure, it's just a baseline to go from. I like researching and experimenting, that's half the fun for me.

And yes there is no reference on those files how wing aspect ratio affects those calculations., I'm curious to know but can't find much on that.
 

Hondo76251

Legendary member
I prefer to use the estimated wing loading as my guidline when building. I like this little calculator here:
http://www.flyrc.com/wing-load-calculator/

The "wing cube loading" factor gives a very good idea of the flight experience you will have. I also use the WCL to estimate the minimum power required. Higher the factor, the more power required to make it enjoyable to fly.

For example, the little scratch built DH.88 I made for the "buildruray" has about 80sq" of wing and weighs 3.5 oz. That means that its WCL is about 8.5 which is about right since it isnt overpowered by any means.

The rest of the proportions are generalizations to use when trying to go for certain flight characteristics. For the same WCL, more chord vs span will give a more sporty feel. You'll have better roll but a less efficient wing. A longer wing will be more efficient (like a slope soaring glider) A shorter coupled plane will be more pitchy and, because of the leverage, often requires larger tail feathers to maintain good stability. A longer fuselage will be much more docile and will be more forgiving about the CG... From there you can start getting into different types of air foils, leading edge flaps, and on and on, but then we are entering a new bottomless rabbit hole...
 

Sero

Elite member
I prefer to use the estimated wing loading as my guidline when building. I like this little calculator here:
http://www.flyrc.com/wing-load-calculator/

The "wing cube loading" factor gives a very good idea of the flight experience you will have. I also use the WCL to estimate the minimum power required. Higher the factor, the more power required to make it enjoyable to fly.

For example, the little scratch built DH.88 I made for the "buildruray" has about 80sq" of wing and weighs 3.5 oz. That means that its WCL is about 8.5 which is about right since it isnt overpowered by any means.

The rest of the proportions are generalizations to use when trying to go for certain flight characteristics. For the same WCL, more chord vs span will give a more sporty feel. You'll have better roll but a less efficient wing. A longer wing will be more efficient (like a slope soaring glider) A shorter coupled plane will be more pitchy and, because of the leverage, often requires larger tail feathers to maintain good stability. A longer fuselage will be much more docile and will be more forgiving about the CG... From there you can start getting into different types of air foils, leading edge flaps, and on and on, but then we are entering a new bottomless rabbit hole...

Yes some good info there.
The documents I attached and referenced have either the wingspan or wing cord to determine the tails length and the results are different. Basically I'd like to make my Bronco long coupled for stability, but I don't want to extend the tail too much and have undesirable flight characteristics or tail heavy problems. I'll have to do a bit more research and make a decision.
I guess that's what you get when you experiment and the beauty of FB.
 

Hondo76251

Legendary member
@Sero as long as you keep the CG correct there is very little penalty for lengthening the tail. I never use ballast when scratch building. I dont like dead weight. I always try to adjust proportions and play with battery size to get the CG set correctly. If you lengthen the nose and move the battery forward you should be good. A longer tail does mean its important to keep it light because it has more leverage and lighter is sometimes weaker... the only drawback I see.
 

BATTLEAXE

Legendary member
@Sero as long as you keep the CG correct there is very little penalty for lengthening the tail. I never use ballast when scratch building. I dont like dead weight. I always try to adjust proportions and play with battery size to get the CG set correctly. If you lengthen the nose and move the battery forward you should be good. A longer tail does mean its important to keep it light because it has more leverage and lighter is sometimes weaker... the only drawback I see.
I think the biggest reason where some make it such a priority to save even grams of weight where ever they can, especially with a Flite Test format, is to keep the plane as slow as possible, advantage to beginners. Weight has advantages as well, and there isn't much that a little more power and speed can't fix (y)
 

Sero

Elite member
@Sero as long as you keep the CG correct there is very little penalty for lengthening the tail. I never use ballast when scratch building. I dont like dead weight. I always try to adjust proportions and play with battery size to get the CG set correctly. If you lengthen the nose and move the battery forward you should be good. A longer tail does mean its important to keep it light because it has more leverage and lighter is sometimes weaker... the only drawback I see.

Oh for sure, but this plane is already built, anytime repairs or mods get done it usually adds weight.

It's in my nature to research a lot before doing anything, I know I'm probably overthinking it. But it's just foam and I love building.

It's all good!:cool:
 

FL_Engineer

Elite member
Alright Gents, I'm back on this thread. Had convinced myself to build the Bronco pusher, then fell in love with the Bushwhacker, then that got sidelined by an impulse buy of a PNP Timber X. So I have a 2836 1500kv and 40a ESC to find a home for and practice some scratchbuild skills. I like the idea of the twin boom bronco with a-tail but I think I may stick with a traditional explorer with extended bronco wing for more portability. Anyone have experience with a V-tail explorer? I thought it may be worth a look at for something different.
 

Sero

Elite member
I figured since I'm running 2 C-pack motors and extra wing span the plane should be able to handle a couple of DIY bombs filled with 100 grams of flour. So I added a bomb drop release that I designed in Tinker cad. One servo to drop to bombs a different times using a 3 way switch.
Hoping to fly it this weekend.


I'll be putting the GoPro on the plane when I do the drops.

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Wildthing

Legendary member
I figured since I'm running 2 C-pack motors and extra wing span the plane should be able to handle a couple of DIY bombs filled with 100 grams of flour. So I added a bomb drop release that I designed in Tinker cad. One servo to drop to bombs a different times using a 3 way switch.
Hoping to fly it this weekend.


I'll be putting the GoPro on the plane when I do the drops.

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LOL, those are cool looking bombs .

Be prepared for the sudden roll when one is only released.
 

BATTLEAXE

Legendary member
Ah it won't be that bad will it? ;)
I'll be ready.... I hope...
I have put a mobius cam on the wing tip of the Sportster and there was a lot of trimming to compensate for the load on the one tip. But your bombs are hugging the fuse so it might not be so bad. It will be worth the epic explosion though.