Originally Posted by alpea 41

Nice colors micro.Top Gun Aggressor sometime in the future

Thank you, I was watching FireFox that old Clint Eastwood movie the other day.

I used Tamiya sprays:
TS-40 Metallic Black
TS-17 Gloss Aluminum
TS-74 Clear Red for the canopy

Maidened the Screamer today and this is one nice flying EDF. Hand launches are very easy and it has a wide speed envelope. As of now the Screamer is the fastest of all the Jpower series I have flow. My F16 with the Wicked 6000 and wemo fan was 94mph flat and level. Here are today's readings on the Screamer in flat level passes.

98,98,94,101,98,102, 97 mph

If you add in a little tailwind and some and some split S runs 110+ mph may be possible on a radar gun

What I really like is no battery hatch mods were needed , no foam grinding like other models in this series. So the easiest to put together and the fastest and nicest one to fly! A real winner in my book.

Model weight less lipo: 10.6 ounces
Ready to fly with a 3S 1800 lipo: 16.2 ounces
Control throws:
up and down: 10mm deflection in each direction
aileron: 5mm deflection in each direction
neutral elevon setting: ~1mm down (see photo)
CG position: ~28mm from inlet lip (see photo)

The CG is spot on and the down elevon trim is needed because the wing has built in relfex into the airfoils which acts like "up" elevon and due to the higher speed of the Wicked setup the reflex will make the model want to climb at higher speed so the CG as shown in the photos and neutral trim setting I have makes the model fly hands off level at full throttle.

Don

Built in reflex is a nice design. The reflex needed on the Mirage and Grippen is rediculus

well it is if u don't want to fly inverted. as w/ any flying wing cg , wingloading and speed determine reflex. if there is large elevon surfaces and lighter wingloading reflex in degrees from neutral can be very small w/ none built in. flying inverted then only requires the same amount . don has shown that w/ enough speed the reflex needed is reasonable on the mirage. the mirage is heavy for it's wing area and that pointy delta is no glider so speed is a must.

i am not bagging on the screamer design , it's a winner, but w/ built in reflex the ability to fine tune the combo of reflex and cg is very limited . this tuning is the key to getting all u can out of any wing type design.

chuck.

double post.

That was a mouth full . And if you said it once you've said it twice...lol I haven't dared to try inverted yet. The video of the Grippens landing plunge is up at the 50mm thread ..

Originally Posted by alpea 41

That was a mouth full . And if you said it once you've said it twice...lol I haven't dared to try inverted yet. The video of the Grippens landing plunge is up at the 50mm thread ..

If I didn't know better, I would swear that plunge was made by an A-10, they are notorious for that.

Ideally you want just enough reflex to overcome the negative pitching moment of the airfoil and no more. I think the CG is suppose to be about 45mm and I am at 28 mm so my CG is forward and I still needed some down trim so that tells me there is too much reflex built in.

Great job as always Don!! Need to get one of these!!

What is everyone using as a thrust tube material? And where can I get it? I printed out the template and now I'm trying to figure out what can I use.

I tend to save the clear plastic sheet that is used on boxes of goods from stores. Alternately, you can get large rolls of mylar type stuff (Duralar for example) at the local arts and crafts store. Then there is always transparent slides available at the local office supply store.

Some people use paper too. I prefer a more humidity-proof material though.

I never thought about the transparent slides. I think that would work perfect. Thanks for the help. Any idea if this thrust tube works with other 50mm edf units? I plan on having a stock t45 50mm and a t45 with dons set up. So for now I was just wondering if I could increase the thrust for the stock set up using this thrust tube.

Thrust tubes help generally with all EDFs, unless the airframe already has the ducting you desire.

There's already alot of information that is better explained elsewhere in these forums. Generally 100% fan sweep area (FSA) will yield maximum thrust, going lower drops thrust but increases the speed of the exiting air (eflux). It depends what you desire.

I would not suggest a thrust tube on the stock power as the stock power on 3S really needs all the thrust available to fly. Thrust tubes are best used on models with excess power so the thrust reduction is not really noticed. The stock power is ~130 watts the systems I typically used are 380 watts on 3S so with a reduced nozzle there is still way more thrust than stock power with no nozzle. Also the thrust tube template I have if for the Wemotec fan unit. Different fans may need different outlet diameters based on the fan geometry.

Ok thanks Don and whiskey whiskey for the input. Don I was looking at ordering a 6000kv motor with the wemotec micro fan. Would this work in a sky angel 50mm t45 with a hobbyking 50amp ESC? If so what batteries should I look at getting like mah wise? I use 800mah 3s 40c skylipos now for my stock t45 set up.