Official Freewing 80mm Avanti S Sport Jet Thread

[Icarus the 2nd]

Here's a vid of a very fast Freewing Avanti S, it has a very powerful Wemotec 80mm 8S unit installed.

Enjoy the vid, it was shot during a very friendly & relaxed EDF meeting in Belgium just 2 weeks ago.

[Av8er278]

Great thanks

[kallend]

Hey guys where can I buy the 3D printed brace for the front landing gear. Thanks.

Wildvortex on RCGroups makes them.

[Av8er278]

Hey guys where can I buy the 3D printed brace for the front landing gear. Thanks.

[Hugh Wiedman]

Thanks. I figured since the flaps were aft of the CG they would tend to rotate the nose down. Shows how much good "thinking about it" does. :)

Regarding the Flap/Elevator compensation, surprised me as well. This is the only EDF I have that way and couldn't explain why if my life depended on it. EVERY other aircraft I have with flaps requires up elevator comp, if anything, so maybe I'm just flying this thing inverted way too much.

When I put my Avanti together, there was no way I could get the book's elevator throws without moving the ball joint connector down one notch. I saw someone else post something about that and I wonder what kind of throws people are using. Go by the book or use it the way it comes from the factory?

In reference to throws, that's kind of a personal preference, but for me on the Avanti, I'm using slightly less than book throws, again, seems to be the only EDF I have like that as well, usually using more (except the ailerons of the F-18). I use a 3 position switch for rates and use Low/Med/High, and for Ailerons, I'm using 16-23mm (book 19-26mm), Elevator 17-22mm (book 22-25mm), Rudder 36--42mm (book 39-46mm), Take-off flaps at 23mm (same as book, but don't use take-off flaps) and Landing Flaps, which I do use at 50mm (book 55mm). Unlike most others, I also use fairly high expos of 35-40%, a left over habit from flying 3D aircraft, and fly it mostly on high rates which keeps it stable around neutral sticks (and keeps me from over controlling it), but gets more aggressive when I need it, just by moving the sticks more. I tried to help a decent pilot at our field who just got an Avanti and he was using high book rates and no expo. I think the overall speed surprised him and how quickly it responded to stick movements and he continually over controlled it, flying it erratically until he finally ended up doing a lawn dart, painful to watch. I kept pleading with him to relax, put it in low rates, land and we'll work in some expo and lower rates, but never got there. Not saying you'll do this, but throws and expo seem to be a very personal set-up, whatever feels best for your flying style.

BTW, you'll really enjoy flying this baby, good luck and enjoy!

[DougCLind]

When I put my Avanti together, there was no way I could get the book's elevator throws without moving the ball joint connector down one notch. I saw someone else post something about that and I wonder what kind of throws people are using. Go by the book or use it the way it comes from the factory?

[DougCLind]

I'm actually using some down elevator mix with flaps, one of the few EDF's I have with that. +4 (servo travel) with take-off flaps and +7 on landing flaps.

Thanks. I figured since the flaps were aft of the CG they would tend to rotate the nose down. Shows how much good "thinking about it" does. :)

[kallend]

No worry Mark. I have been flying my Avanti all summer with the FMS 80mm 2100KV fan and a 100Amp ESC. Works perfect. I have also done a few flights with the X-Fly 80mm 2200KV fan. There was no improvement over the FMS fan and the X-Fly puffed-up 2 5200mAh 100C batteries. So I pulled out the X-Fly and went back to the FMS. The 100A ESC handled all of this OK.

I'm running the same for over year now, with no problems.

Pic shows my 3DP "Chevron nozzle" (like the B787 has for noise reduction).

[Mach9]

STUCK FLAP ISSUE SOLVED
I think I have found the cause! Using a spare wing, I connected a servo driver to the flap servo. When fully deployed, I applied pressure with my finger (simulating airflow) to the flap and in less than 10 seconds the servo shut off to save itself from burning. After the pressure was released, It reset quickly and would start working again when the driver was operated or the flap was moved. I did this several times with consistent results. You can easily test this yourself. It looks like the servos are just strong enough to work. The good news is that they don't burn. If full flaps are deployed at too high of a speed and the the speed/pressure is not reduced quick enough, the servo will shut off. If the servo travel is too far and binds at full deployment, it will also shut off. Since I have changed my full flaps to less than 100%, I have not once had a problem with the 2 Avanti jets I am flying. I would have thought Freewing would have found this and reported it!

[Mach9]

Info that may be useful. Forgive me if this is redundant or out of place. Correct and/or add whatever you think is needed. Hope this helps.

Batteries & Power
All sellers lie, it is only a question of how bad.
If you assume 50% of the rated C, you should be good.
Higher V - higher price, more weight, cells & power.
Higher A - higher price, more weight & run time.
Higher C - higher price, more weight & power.
Lithium Polymer (There are many types of Lithium.)
Voltage Max 4.20, Dead 3.27, Safe Min 3.71, 3.75 better, Store 3.84
Temp Max 140F, Min 32F, Ideal 110F
Max current available AxC. Max power in Watts VxA
Lo A pack needs higher C to equal same power as hi A pack.
2.5A x 40C = 100A 5A x 20C = 100A
Hi V with Lo A gives same power as Lo V Hi A.
4V x 5A = 20W 8V x 2.5A = 20W
Hi V uses smaller, lighter, less expensive wire and connections.
Hi V uses more expensive ESC. Danger of shock past 50V and will arch.

Run Time
Assuming the pack capacity is accurate, which it is probably low.
Measure the Amp draw at various throttle positions.
Use the ESC rating as the max.
100A ESC / 5A pack = 20 (You need 20C so use a 40C pack.)
60 Min / 20 = 3 Min until DEAD pack (BAD!)
3 Min x .8 = 2.4 Min (2 Min 24 Sec) runtime with 20% reserve.
100A ESC / 3.3A pack = 30.3 (You need 30C so use a 60C pack.)
60 Min / 30.3 = 1.98 Min (1 Min 58.8 Sec) runtime with 20% reserve.
At an average 50A draw, the runtime will be twice.
Roughly 5 Min with a 5A pack and 4 Min with a 3.3A pack.

Brushless Motors
Without brushes there are no wear, bounce, arch and speed/balance problems.
Descent motor bearings can run faster than any fan can withstand.
Silicone insulation 600V-1000V and 482F (302-572F). PVC 221F, Teflon 842F.
Magnet wire insulation 600V-thousands and 221F-428F to as high as 1000F.
Metal melt points: Copper 1984F, Silver 1761F, Aluminum 1220F, Lead 621F, Tin 449F.
Copper wires can be bare, tinned with solder or silver clad.
Solder (If used, usually crimps or welds internally) melt points:
63/37 361F, 60/40 361F-374F, 95/5 450F-464F
Neodymium Iron Boron magnet grade max temp:
N 176F, NM 212F, NH 248F, NSH 302F, NUH 356F, NEH 392F, NAH 428F
Magnet glue max temp:
I don't know about the factory glues.
J-B Weld epoxy 500F
Some people use Loctite 480 (A type of CA/super glue) which is only 180F.
Bearing lube max temp:
160F-180F
Some electric motor grease can go to 500F, but I don't know of any for RC use.

If the heat is kept below 140F, you can safely run any motor VERY hard at higher voltage.
Most will run over 200F at a reduced lifespan. Wattage creates the heat.
The fan shroud needs to be metal to draw heat and not distort. The RPM of the fan
must not be exceeded and of course proper balance is always needed.
Increase fan diameter for more thrust/punch/torque and increase pitch for speed.

EDIT: "60 Min / 30.3 = 1.98 Min (1 Min 58.8 Sec) runtime with 20% reserve."
Should be 60 Min / 30.3 = 1.98 Min (1 Min 58.8 Sec) until DEAD pack (BAD!).
1.98 Min x .8 = 1.584 (1 Min 35 Sec) runtime with 20% reserve.
"Roughly 5 Min with a 5A pack and 4 Min with a 3.3A pack."
Should be Roughly 5 Min with a 5A pack and 3 Min with a 3.3A pack.

[Hugh Wiedman]

Just finished building my FW Avanti S. They don't seem to mention what kind of elevator mix you need with the flaps so I'd like to hear what others have found. I'll maiden without any elevator mix and see what it does but I'd still like to hear what other people are using. I'm guessing it will need a little up elevator with full flaps for landing.

I'm actually using some down elevator mix with flaps, one of the few EDF's I have with that. +4 (servo travel) with take-off flaps and +7 on landing flaps.

[DougCLind]

Just finished building my FW Avanti S. They don't seem to mention what kind of elevator mix you need with the flaps so I'd like to hear what others have found. I'll maiden without any elevator mix and see what it does but I'd still like to hear what other people are using. I'm guessing it will need a little up elevator with full flaps for landing.

[Mark70]

Curious. What are you using for Telemetry??

Jeti MUI150. It’s new so hopefully accurate

Mark

[Scott Page]

Just Maidened the PNP version which went really well. Telemetry says peak 108amps but stock it’s 100 amp speed controller. Do I need to be worried?

Thanks

Curious. What are you using for Telemetry??

[AFTERBURNER]

Thanks #afterburner. Just a bit supervised to see 108 amps. Looks like I will be ok and cannot wait to go again .

I got in some more flights on my Avanti today. Some of the decals are starting to peel off, but it's flying great. IMO as long as we are flying with 6S LiPos, the 100Amp ESCs will handle the AMPs

[Mark70]

Thanks #afterburner. Just a bit supervised to see 108 amps. Looks like I will be ok and cannot wait to go again .

[AFTERBURNER]

Just Maidened the PNP version which went really well. Telemetry says peak 108amps but stock it’s 100 amp speed controller. Do I need to be worried?

Thanks

No worry Mark. I have been flying my Avanti all summer with the FMS 80mm 2100KV fan and a 100Amp ESC. Works perfect. I have also done a few flights with the X-Fly 80mm 2200KV fan. There was no improvement over the FMS fan and the X-Fly puffed-up 2 5200mAh 100C batteries. So I pulled out the X-Fly and went back to the FMS. The 100A ESC handled all of this OK.

[Mark70]

Just Maidened the PNP version which went really well. Telemetry says peak 108amps but stock it’s 100 amp speed controller. Do I need to be worried?

Thanks

[Hugh Wiedman]

Scott Page outstanding looking Avanti, love it in green. Great photos BTW, and the AB's are a must, well done!

[Scott Page]

I finally finished and maiden flew my Green Avanti. It has GPS for ground speed, Vario for altimeter, Cell voltage with low cell warning, Amp and mAh telemetry. Have the Afterburner with silver tape in the duct. This is #1 based on a yellow ARF, #2 is underway based on red ARF. I made two green because I got frustrated part way with #1 and was going to abandon the project and started #2. Then I corrected the issues with #1 so I have two. #2 won't have as many bell and whistles (at this time).