Official Freewing Twin 80mm/90mm A-10 Thunderbolt II Thread

[Hugh Wiedman]

What i have been doing to check cg is to go high and cut power then push over to a 45 degree dive and release the elevator, most likely the plane will pull out of the dive, not abrupltly but will depending on how much elevator trim is in place. I fly with cg at 85-90 depending on what batts i fly with and that can be 6250 stacked to the rear or two 8000 in same place.

Slight variation on your 45 degree test, as recommended by Chris Hinson, Pres of Extreme Flight (which I have adopted as well). "After trimming for level flight, fly at about 3/4 throttle and pull the aircraft to a 45 degree up line and establish this line, then immediately roll inverted. Establish this line, then let go of the elevator stick. For a neutrally balanced aircraft, it will continue to track on that 45 degree line for several hundred feet before slowly starting to level off." I like this a little better as you're gaining altitude instead of heading towards the ground, always a bit unnerving. Of course, if you're nose heavy, you've added plenty of up trim to correct it, which will become quite evident while inverted.

With that said, CG is a somewhat personal preference and we know some like their aircraft a little nose heavy, others like it a little tail heavy, and virtually every type of aircraft is different it it's flying characteristics under each condition, so in the end, fly it where you personally feel best.

[sam51401]

I believe as was mine to start with, the top of the elevator should be level, ie even with the top of the stab with a straight edge placed across stab and elevator. Another ref used is the two rear radar warning sensors, "round little bumps", elevator trailing edge pointing to those. This also goes with what cg your set at and how much trim is needed for level flight. What i have been doing to check cg is to go high and cut power then push over to a 45 degree dive and release the elevator, most likely the plane will pull out of the dive, not abrupltly but will depending on how much elevator trim is in place. I fly with cg at 85-90 depending on what batts i fly with and that can be 6250 stacked to the rear or two 8000 in same place. This with Dirtty Dees more scale nozzles has greatly lessened the bounce and along with learning to work the power and flare more. This plane IS NOT one to just cut power with a forward or stock cg and yet others have learned to manage it with plenty of practice. Hope this helps as i have become more comfortable and relaxed in flying this with these minor changes.
On another note as i make known another "mod" is for the retracts.
JP Models has a set that i found by accident, that are the metal type and are a mounting hole drop in replacement. I will report more as i mod mine and replace just the nose unit for the time being. No more play in the trunnion with this swap from the stock unit. Im using the oleo mains at the moment and stock strut on nose so oleos all around since i fly off a paved surface.

[DCORSAIR]

Oops, posted after you guys did, looks like you figured it out.

[DCORSAIR]

Had a successful maiden today! Did you guys need a lot of up elevator trim to keep the nose up?

Yes, the trailing edge of the elevator should be lined up with those little bumps sticking out on each side of the rear of the fuselage to start with, then it depends on your CG to trim in flight, did you add more trim or start with the neutral starting point?

[AndrewF]

If you set the elevator (as per the manual) with about 3mm to 4mm of UP ELE to begin with, very little ELE trim should be needed when flown, assuming you've balanced it at the recommended CG (more or less).

I think I forgot to se that 4mm of up trim… oops… I have the CG at 90mm so it makes sense it would probably need a little more than that too. I’ll have to measure and see how much deflection it’s at, just out of curiosity.

[xviper]

Had a successful maiden today! Did you guys need a lot of up elevator trim to keep the nose up?

If you set the elevator (as per the manual) with about 3mm to 4mm of UP ELE to begin with, very little ELE trim should be needed when flown, assuming you've balanced it at the recommended CG (more or less).

[AndrewF]

Had a successful maiden today! Did you guys need a lot of up elevator trim to keep the nose up?

[sam51401]

This one goes against all foam paint practices but I’m going for it. Will build out my backup A10 with this Cenntinial 100 year ING scheme and twin 90mm fan upgrade.

[AndrewF]

Well said, adding a touch of throttle with the flare is key, almost counter intuitive, but really gets the job done on virtually all jet landings. I have to force my brain to remember that everything time, but still not consistent with it. All the "top" jet pilots I speak to tell me the same thing, but like they say, "You can lead a horse to water, you just can't force him to drink".

Agreed. My first EDF was the Eflite 70mm viper and I couldn’t grease the landings until I learned to keep maybe 20% power in when flaring then slowly letting it come down.

[AndrewF]

Take your time and you won't have any trouble, I flew mine all stock and after many many flights it was fine, I never had the bucking bronco thing happen to me so I don't have any experience there, just don't get it to slow and plop it down, it will come in nice and slow but when you flare add in throttle while holding the nose up, it will grease the runway nicely on the mains everytime.

I’m definitely excited, it looks like a stable plane on approach in all the videos I’ve seen.

[Hugh Wiedman]

Take your time and you won't have any trouble, I flew mine all stock and after many many flights it was fine, I never had the bucking bronco thing happen to me so I don't have any experience there, just don't get it to slow and plop it down, it will come in nice and slow but when you flare add in throttle while holding the nose up, it will grease the runway nicely on the mains everytime.

Well said, adding a touch of throttle with the flare is key, almost counter intuitive, but really gets the job done on virtually all jet landings. I have to force my brain to remember that everything time, but still not consistent with it. All the "top" jet pilots I speak to tell me the same thing, but like they say, "You can lead a horse to water, you just can't force him to drink".

[DCORSAIR]

thanks for the tip. Luckily I’ve got a long runway where I fly so there’s not a ton of pressure to get it on the ground as fast as possible.

Take your time and you won't have any trouble, I flew mine all stock and after many many flights it was fine, I never had the bucking bronco thing happen to me so I don't have any experience there, just don't get it to slow and plop it down, it will come in nice and slow but when you flare add in throttle while holding the nose up, it will grease the runway nicely on the mains everytime.

[AndrewF]

Good luck with the maiden. It's not necessarily the struts that help avoid the dreaded bounce. It's more landing with too much speed and letting the nose wheel touch first. This one needs to land with the nose up on the mains first.

thanks for the tip. Luckily I’ve got a long runway where I fly so there’s not a ton of pressure to get it on the ground as fast as possible.

[Hugh Wiedman]

Just about done with paint and decals. Hopefully will maiden this weekend. I’ve got the CG set at 90mm and struts installed on the mains to help avoid the dreaded bounce.

Good luck with the maiden. It's not necessarily the struts that help avoid the dreaded bounce. It's more landing with too much speed and letting the nose wheel touch first. This one needs to land with the nose up on the mains first.

[AndrewF]

Just about done with paint and decals. Hopefully will maiden this weekend. I’ve got the CG set at 90mm and struts installed on the mains to help avoid the dreaded bounce.

[xviper]

About the tenth landing. I left the original chassis. I have never experienced such a jumper. Normal landing, but a little higher speed. Hop, hop, hop and the end ....

Been there, done that. Repaired and it flies again. That was fairly typical (bouncy landings) when this plane first came out, but it still happens.

[Miroslav Cerny]

About the tenth landing. I left the original chassis. I have never experienced such a jumper. Normal landing, but a little higher speed. Hop, hop, hop and the end ....

[AndrewF]

Could be a bad/cold solder joint, but definitely sounds like a BEC issue. If it's new, have MRC replace it. If not, to be on the safe side, I would suggest installing a new BEC.

It’s brand new, but yeah I played it safe and just ordered a new BEC. They aren’t expensive compared to buying a new plane if the other one fails.

[Hugh Wiedman]

has anyone had issues with their receivers not getting power? I've double checked all wires are hooked up correctly to the board and the receiver, but when I plug batteries in, the motors just beep and the receiver doesn't power on. I hooked up an external battery to the receiver and everything worked fine.

*update*
after further testing I think it could be a bad BEC. I tried leaving the BEC connected to the receiver, then connected a battery to the receiver, and the BEC lit up. It's almost like the connection going from the main EC5 battery connector to the BEC is the issue.

Could be a bad/cold solder joint, but definitely sounds like a BEC issue. If it's new, have MRC replace it. If not, to be on the safe side, I would suggest installing a new BEC.

[Hugh Wiedman]

Thanks for the kind words Hugh. This was an ARF Plus and I put FMS 2100KV 80mm units in it and have flown it many times...it is faster than a friends 90mm A-10 at our field....so fast it isnt anywheres near scale....I only decided to paint it so it could be different than all the rest after I had it all dialed in....I did convert the gear as I fly off a asphalt runway and didn't like the "frog-hopping" that I saw with the"grass gear"on pavement....Very forgiving and enjoyable aircraft to fly ....I have many Motion RC EDF's and this one is a KEEPER.

Well said on all fronts! Different is almost always better, and yours looks great, excellent choice of livery and it's a really fine looking Hog! I can only imagine (with a bit of jealousy) that those FMS fans really make her sing!