Official Freewing 70mm F-16C Falcon V2 Thread

[Suprawill1]

Well, there you go. No doubt that's why you're having a CG problem.

Not sure which case you're referring to. The ESC, the EDF, the battery, the position of the ESC?

[kallend]

70mm RC Lander 2200kv EDF and a 100A ESC. Another difference is that I have a 3200mah which is probably lighter than the 4000 pack. A 4200 is on the way but in its own right is a bit light for its amperage. 440.4g as opposed to the 3200's 394.8.

Well, there you go. No doubt that's why you're having a CG problem.

[Suprawill1]

Leave the ESC, where it is is a good place in air flow for cooling. Moving it you'll need to do a lot of soldering too.

Agreed. It's where it is because of the cooling factor but I may have to move it forward if there continues to be a balancing problem. It was a hard decision between the two places because there were other concerns. Besides the balancing, it's prudent to have the motor wires long and the batt wires short. That way I wouldn't have to add caps.
Not afraid to solder but there's also crimp connectors.

[Suprawill1]

What have you got that's heavy back there? I have no trouble at all getting the CG in the right place with a 4000mAh pack, and it doesn't have to be all the way forward.

70mm RC Lander 2200kv EDF and a 100A ESC. Another difference is that I have a 3200mah which is probably lighter than the 4000 pack. A 4200 is on the way but in its own right is a bit light for its amperage. 440.4g as opposed to the 3200's 394.8.

[Evan D]

Leave the ESC, where it is is a good place in air flow for cooling. Moving it you'll need to do a lot of soldering too.

[kallend]

That would be more like a half inch, not 1 5/8". I had the wrong battery in it. A half inch is still too tail heavy for me. Any thoughts? Not trying to add more weight to balance it out.

What have you got that's heavy back there? I have no trouble at all getting the CG in the right place with a 4000mAh pack, and it doesn't have to be all the way forward.

[Suprawill1]

That would be more like a half inch, not 1 5/8". I had the wrong battery in it. A half inch is still too tail heavy for me. Any thoughts? Not trying to add more weight to balance it out.

[Suprawill1]

Where are you F-16 flyers mounting your ESC? I mounted mine on the wooden rail in front of the EDF and now I may have to relocate it to the battery area because the plane is way too tail heavy. The cg is a good 1 5/8" behind the recommended cg and that's with battery as far front as it will go.
Thanks for your replies.

[Suprawill1]

Just got this nice looking bird and plan on sucking up some insects.
There is an angled slot on the vertical stab just under the servo. Does anyone now what this is for? I'm about to apply some decals and one of them would cover this slot.
Also, when applying the strip decal across the very top of this stab, do you bury it into the hinge area or are you cutting it so it doesn't bind?
Thanks for your thoughts.

[Suprawill1]

You mean Motion in Chicago? Can I suggest better batteries? Admirals are okay but not what I call a value. I am using Hobby Star 3500 35C in mine from RC Juice and Power Hobby 5000 100C from Power Hobby. The 5000 are not cheap but they are super light weight @575g and really perform great.

Powerhobby 6s 22.2v 5000mah 100c Lipo Battery w EC5 Plug Soft Case 6-Cell - Powerhobby.com

Good suggestion but here's what I found. Per your Hobby Star recommendation, you can get 2 3S high voltage 4100mah, 100C lipos weighing in at only 440g total. (wired in series for 6S) That seems like a bigger kick than the Admiral Pro 4000mah at close to the same price and considerably lighter.

https://www.rcjuice.com/lipo-batteries/3s-hv-11-4v/hobbystar-4100mah-11-4v-3s-hv-100c-lipo-battery.html

As far as the Power Hobbys, if you back down to the 4200mah, you can get a graphene version, also HV and 120c, only weighing in at 442.4g.

https://www.powerhobby.com/6s-4200mah-120c-ec5.html

[Evan D]

You mean Motion in Chicago? Can I suggest better batteries? Admirals are okay but not what I call a value. I am using Hobby Star 3500 35C in mine from RC Juice and Power Hobby 5000 100C from Power Hobby. The 5000 are not cheap but they are super light weight @575g and really perform great.

Powerhobby 6s 22.2v 5000mah 100c Lipo Battery w EC5 Plug Soft Case 6-Cell - Powerhobby.com

[Shadow3g]

Thanks Evan, I and appreciate your response, you're right, I left out a 0 on the 6000, I'm going to purchase the required 6S 22.2V 4000 this week, lucky for me Freewing is only 20 minutes down the road, so I order and pick them up the same day, thanks again.

[Evan D]

Not sure what you are asking. 4S 600 14.8 mAh battery 50C tells me you have a 4S (14.8V nominal) 600mAh 50C battery. I think you are saying you bought a 4S 6000mAh battery??

Maybe this one? Admiral Pro 6000mAh 4S 14.8V 50C LiPo Battery with EC5 Connector [EPR60004E] Motion RC

At 624g It is pretty heavy for the 70mm F-16 and because its 4S, 14.8V nominal, it will be very low powered. The F-16 should be used with a 6S, 22.2V nominal battery.

[Shadow3g]

I accidently purchased a 4S 600 14.8 mAh battery 50C would that be to much battery or should I just cap it off at a 6S 4000?

[kallend]

I have twice broken the little tabs on the cheater grill where the ventral fins attach, due to landing in the grass.

Here is a revised version of my 3DP cheater grill with the more robust tabs.

https://www.thingiverse.com/thing:4981056

[paulrkytek]

did something similar using sharp metal tube as a hole maker just above the ventral fins, hard to see in black but it worked well

[Cape Jets]

I believe I originated that mod. From 2017:

https://www.rcgroups.com/forums/show...postcount=2795

My friend went with the kallend suggestion of the openings in the main wheel bays. Took her out for a re-maiden last weekend and showed a good improvement on take off rotation (without flaps) and overall speed. After doing more research, I noticed that all other makes of F-16's 70mm or larger have side cheater vents behind the main landing gears. I went with that option on my F-16 70mm and created new openings behind the mains on the fuse. Haven't flown her yet as I am in the process of a new paint livery for this bird, but looking forward to seeing how the additional air intake works.

[kallend]

A friend of mine who also has a F-16 70mm Artic Camo noticed a loss of thrust on rotation. He did some digging and found some info on opening up holes on the main retract wheels in the fuse to create more air to the EDF. He states that this bird is restricted with air flow from the air intake. The front landing gear eats up alot of space in the front air intake causing poor air flow. After cutting the holes he said he noticed an increase of thrust by 15%. Have any of you done this mod ?

I believe I originated that mod. From 2017:

https://www.rcgroups.com/forums/showpost.php?p=38614366&postcount=2795

[Cape Jets]

A friend of mine who also has a F-16 70mm Artic Camo noticed a loss of thrust on rotation. He did some digging and found some info on opening up holes on the main retract wheels in the fuse to create more air to the EDF. He states that this bird is restricted with air flow from the air intake. The front landing gear eats up alot of space in the front air intake causing poor air flow. After cutting the holes he said he noticed an increase of thrust by 15%. Have any of you done this mod ?

[gazza]

Does anyone have the aileron servos configured as flaperons? If so, are they useful to reduce airspeed on landing?

i have the ailerons set up as just flaps, and the elevator set up as tailerons, flys great