Foamboard F-22 EDF
- Thread starter Grifflyer
- Start date
Any chance you could share the needle cutting files?
What size battery? On my eflite f-16 I get 3:30 flight time on a 2200 4s.
Grifflyer
WWII fanatic
Yup that’s around what I get.
2jujube7
Well-known member
Did you start/finish your needlecutter?
Sero
Elite member
Doing some research, others are saying the 3s fan only produces 500 grams thrust. So i found and ordered a 4s fan on Amazon for the same price but should be here much sooner, that will go into the F22.
Then I decided to design and 3d print a mount for the 3s fan to put on my thrust stand only to find out that it does do 650g fairly easily, so that will go onto my Tiny Trainer glider....should move well.
Sero
Elite member
Should be attached. I haven't got my needle cutter yet so I have no idea if they're good files.
Awesome, thanks!
The replacement aurduio arrived from china (finally) but neither me nor my buddy have had the time to install it. Hopefully between the two of us we can get it figured out over spring break...
mine was a 1,300 mAh 3s. Sounds like I need to dial in the controls so I can just Fly! time to get more 1300mAh 3S batteries. has anyone tries to melt a bottle to make a canopy using the Foam version as a Buck? (I've never made a heat-molded canopy. This model seems worth a try.
Grifflyer
WWII fanatic
That’d be really cool! I don’t think it’s been done yet
Finally got a maiden in, right into the ground. I've got the battery mounted as far back as I can and it's still pretty nose heavy. It felt like it's either too nose heavy, or just didn't have enough power to get going. Threw it pretty quick to start, looks like I'm rebuilding the nose and reevaulating where all of the electronics are going to sit for the next round.
AussieBison
Well-known member
That's not very good.. but don't give up, never give up
what battery did you use? Measuring thrust (with the battery you're planning on using) before maiden-ing may also help.
Members (I don't remember their names, sorry) suggest 1:1 AUW thrust ratio for hand launching. And if you add landing gears and have long enough runway for take off, around 0.6 ration should work too (again, I haven't tested this numbers myself.. but something I would consider for EDF jets)
Use a turnigy 1300mAh 4s (https://hobbyking.com/en_us/turnigy-nano-tech-1300mah-4s-45-90c-lipo-pack.html), did not measure thrust before hand. I'll have to get out the 'ole water jug and harness before I try it again to ballpark the thrust. Running out another set of plans now...
AussieBison
Well-known member
Yeah, 1300 4S should have been fine. Well, once you have rough idea of thrust (and AUW), you can rule out lack of power. CG would be the only thing to double check then.
Also, If you didn't feel comfortable hand launching the beast, maybe try getting ideas from the videos on this thread.. those launches have proven to be working
Good luck for the next flight, and keep us posted..
Grifflyer
WWII fanatic
I’m sorry to hear that. It sounds like it’s either too nose heavy or not a strong enough launch as you were saying. Where is your Cg currently?
You could stick nickels in the back?
Pieliker96
Elite member
I've gone as low as 0.58 for runways. As long as the thrust-to-weight ratio is greater than the inverse of the glide ratio (drag-to-lift ratio), it'll be able to fly - the only constraint then is the length of the runway - some IRL jets get away with TWRs less than 0.2! When acceleration to flight speed with an initial launch speed of below stall speed is needed, high TWR is the way to go.That's not very good.. but don't give up, never give up
what battery did you use? Measuring thrust (with the battery you're planning on using) before maiden-ing may also help.
Members (I don't remember their names, sorry) suggest 1:1 AUW thrust ratio for hand launching. And if you add landing gears and have long enough runway for take off, around 0.6 ration should work too (again, I haven't tested this numbers myself.. but something I would consider for EDF jets)
So my all up is 19oz. Only thing I can think of to do to reduce weight would be some lighter linkages, I'm using metal marker flags Balancing it on the scale and 100% throttle on a full battery pack adds 10~11oz. That's probably not very accurate thrust measurement, but it is worry some, that's just over .5. For the record, using the following power plant:
1300mAh 4s turnigy battery
powerfun 50mm 4300kv edf (I pulled the front plastic shroud)
40a esc
I shoved the receiver back in the first pocket before the fan, so the center of gravity is much better, but the lack of thrust still worries me.
Maybe I butchered my thrust tube and it's spilling out internally?
1300mAh 4s turnigy battery
powerfun 50mm 4300kv edf (I pulled the front plastic shroud)
40a esc
I shoved the receiver back in the first pocket before the fan, so the center of gravity is much better, but the lack of thrust still worries me.
Maybe I butchered my thrust tube and it's spilling out internally?
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