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JH Speed Deamon - a foamboard pylon racer

L Edge

Well-known member
#41
If you designed a cooling inlet up front for the battery and have an exit below the elevator, why opening behind wing? If that is needed, did you experiment with opening on bottom or sides due to airflow?

How about getting rid of 2 aileron servos and mount one inside? Less drag?
Look at securing wing and not using rubber bands and pegs?
Play with changing wing angle a small amount. We use to race 1/2 A's and this help reduce the CD and made it a winner.
Need to explore prop size and pitch so it will unload in the air. Take a look at APC's prop.

It is all about reducing the drag, even on 65% nito Formula One's, we scotch tape the wing at the fuse to reduce drag. Highest radar speed we got was 207 with a modified wooden prop.
 

FAI-F1D

Free Flight Indoorist
#42
Since our radar runs have been getting more and more sketchy, with several of the crashes directly caused by the tight space we're flying in, I decided to stop testing the Super Deamon out here.

Still had to do something silly.

And so I scaled the Speed Deamon to 50% and build it from balsa!
IMG_20190705_190810.jpg

Weighs 2.6 oz and power is a 2s 350 driving a 4.1x4.1 APC on an Emax RS1306-3300. It's decently quick, and very hard to follow, but I do want to try 3s eventually. Glide isn't bad considering that it's so tiny and I don't have the ESC brake programmed.
 

FAI-F1D

Free Flight Indoorist
#43
If you designed a cooling inlet up front for the battery and have an exit below the elevator, why opening behind wing? If that is needed, did you experiment with opening on bottom or sides due to airflow?

How about getting rid of 2 aileron servos and mount one inside? Less drag?
Look at securing wing and not using rubber bands and pegs?
Play with changing wing angle a small amount. We use to race 1/2 A's and this help reduce the CD and made it a winner.
Need to explore prop size and pitch so it will unload in the air. Take a look at APC's prop.

It is all about reducing the drag, even on 65% nito Formula One's, we scotch tape the wing at the fuse to reduce drag. Highest radar speed we got was 207 with a modified wooden prop.
Some interesting topics...

Everything I've done has been run through Ecalc in advance, and I've been tuning drag coefficients based on radar runs. Looks like the stock Speed Deamon has a Cd of ~0.3 using frontal area, with the Super Deamon slightly less. We've been running APC props exclusively since the second plane was trimmed out.

Since the servos are flush mounted, there's little drag to be removed from putting them inside and running torque rods. Plus I find it pretty telling that the F5D guys have moved away from torque rods to wing mounted servos. Torque rods are a packaging nightmare since they get in a fight with the battery, and slimming down the fuselage cross section *seems* to be more important than eliminating exposed pushrods.

I put the exhaust in the back since the GP Rifle and several other planes use it, however the latest Super Deamon version doesn't have it or the NACA duct. Instead I put airscoops on the sides to blow air over the motor casing, ESC, and battery, and then out the tail. It still gets hot as blazes in there.

The wing bands remain a problem and I'd like to get rid of them, but gluing the wing on is a weaker structural setup and leaves me with the problem of battery access. Right now I don't have to velcro the battery in, allowing a tighter fit in the fuselage, but a bottom hatch would require that and then I'd have to deal with keeping the hatch secure. A pain in the neck to say the least. Many of the top F5D planes eliminate this via removable nose with a battery tray, but I don't know of a good way to do that with foamboard without either making the plane disposable after the first less than flawless landing or increasing the fuselage cross section excessively. Plus we still haven't gotten around that wing security issue.

Of course there is one end-all solution: bolt the wing on, using plywood hardpoints. Not ideal for a foamboard plane that I'm trying to make accessible for others, but I'm warming to it after all the problems I've had keeping the wing in place on my 64" Hot Deamon.
 

jpot1

Well-known member
#47
What a fast and fun flying plane. Flew like a rocket, at least for my flying style. Easy to control and looked great in the air!
 

FAI-F1D

Free Flight Indoorist
#48
What a fast and fun flying plane. Flew like a rocket, at least for my flying style. Easy to control and looked great in the air!
Awesome! A kid bought one of the kits at Flite Fest and had it running down the runway like a veritable drill bit. Amazing flying skills...I wish I could fly half that well. As it was I did a top speed of 115 mph on the Super Deamon on 50% power before Ben crashed without getting a radar reading. After that I decided to just bring it in and land since I'd already crossed the flight line once trying to make my pattern stay out of the sun.
 

Chuppster

Well-known member
#49
Awesome! A kid bought one of the kits at Flite Fest and had it running down the runway like a veritable drill bit. Amazing flying skills...I wish I could fly half that well. As it was I did a top speed of 115 mph on the Super Deamon on 50% power before Ben crashed without getting a radar reading. After that I decided to just bring it in and land since I'd already crossed the flight line once trying to make my pattern stay out of the sun.
The brown-outs claimed many this year. That and mid-airs.
 

jpot1

Well-known member
#55
150% build done. Slapped a 3015 1200kv motor on the front. With a 3s 2200 in the middle of the fuse opening it balances perfectly. 10x6 prop.
Need a little color for orientation and hoping to maiden on Saturday.

B843C4D7-5637-4E3A-BAD3-C25EA70A5EE3.jpeg
 

IanSR

Active member
#57
I've built one similar that is about 175% (I wanted to keep it to 2 sheets so scaled it up to that) and put a 1800kv with a 7x6 prop, boy does it shift lol. Not had chance to put the DJI gear on it yet as that took damage in a mid-air with a Tundra but the regular size one was a blast with it on.

What is your wingspan on that @jpot1?
 

jpot1

Well-known member
#58
I've built one similar that is about 175% (I wanted to keep it to 2 sheets so scaled it up to that) and put a 1800kv with a 7x6 prop, boy does it shift lol. Not had chance to put the DJI gear on it yet as that took damage in a mid-air with a Tundra but the regular size one was a blast with it on.

What is your wingspan on that @jpot1?
Mine is about 42” wingspan. Researching bigger motor options or maybe 4s even though motor only is rated for 3s. :eek:
 

IanSR

Active member
#59
We put 4s on mine on Sunday and it did a backflip when I opened the throttle, soooo much power.
It also had down and right thrust built in, never seen a plane flip so quick lol

Mine is 33" wingspan and I checked, it's 133%.
 

FAI-F1D

Free Flight Indoorist
#60
Guys I love seeing these upscales. If y'all want to go *really* fast, start looking at higher voltages and oversquare props. My 50" Deamon clocked 130 mph on a 4250 800 kv motor on 8s, turning an APC 9x10. I used an 80A ESC and it never got particularly warm.