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

[BBriBro]

Wondering if people are replacing the nosewheel strut spring with a softer one ? The stock one seems very stiff and takes quite a bit of force to get any movement/compression.

Thanks. Bob

I am using this one, They claim it has a stiffer spring, but the geometry makes it feel better. Maybe not for purely vertical action, but if you run into something, the trailing link should help a lot if you hit holes, ruts, or the edge of the runway if you ran off and are taxiing back.

[Balsa Bob]

Wondering if people are replacing the nosewheel strut spring with a softer one ? The stock one seems very stiff and takes quite a bit of force to get any movement/compression.

Thanks. Bob

[BBriBro]

I can't speak for how you've done it with your Taranis, but on my Spektrum, there is another "shared" connection, that being the two reverse leads that are Y'd together and goes to an unused channel on the RX.

You are correct, I misspoke, they are also Y'd together and connected to an Aux channel for reverse. I haven't messed with any variance to the travel on that channel though, I set it up the way they said and since it activated reverse I figured It was correct. The way I understand it, there is no "variable" (proportional) there, the Aux channel is either enough or not enough "travel" to signal reverse. I did however run them with the reverse wires disconnected and the reverse function disabled via the programmer just like a "regular" ESC which should have eliminated any potential issues like this, but that is certainly something else to check, which I hadn't thought of.

[xviper]

with the only shared connection at the receiver with the throttle signal

I can't speak for how you've done it with your Taranis, but on my Spektrum, there is another "shared" connection, that being the two reverse leads that are Y'd together and goes to an unused channel on the RX. This is then controlled by a 2 position switch. On my Spektrum, that channel must have the servo travel set to 50:50 (end limit for each switch position).
I am also currently having a similar problem with my AL-37. After a full throttle take off, the motors shut down until I zero the throttle, then I'll have power again for a few seconds before it shuts down again. The last shut down, I didn't have enough power to come around for a "dead stick" and crashed into some tall grass. I have not had time to diagnose the problem as this will be a winter project. I have plenty of other planes to fly till then. Your solution will be of interest to me.

[BBriBro]

Unplug one of your ESCs and try your tests with just one motor+ESC hooked up.

I have a feeling that the two ESCs might be fighting each other. Some ESCs will play well with each other in a twin setup, and some won't.

If you are using a separate BEC then you need to cut the red wire that is going from the ESC to your throttle input on the receiver. (that wire is sending voltage to the receiver from the ESC, and multiple inputs could be causing this interference.) But don't do that until after you figure out what's going on.

I'm interested in seeing other's opinions, I'm just offering a hunch.

That's certainly worth a try, (I'll report back) The 2 ESCs are separate with their own battery, own motor, etc, with the only shared connection at the receiver with the throttle signal, but who knows? Both of these ESC have a built in BEC, but I have pulled both red wires, using a separate 8A UBEC.

[themudduck]

Seeking help troubleshooting ESC's. My A-10 was working just fine, but I wanted to have reverse thrust. It's all the rage and I wanted to be unique and have the only TWIN EDF with reverse at the club. I bought 2 Hobbywing FlyFun V5 120A ESCs. (both BECs have been disabled) They are nothing but trouble, I have been through every setting, spoke with HW tech support, Motion RC tech support, and none of their suggestions help. I'm really am at a loss here. I have tried virtually every combination of settings (and several different batteries). (I have also reinstalled the OEM ESCs to rule out a bad motor that just failed during my “upgrade”. And the stock ESC’s work fine).

Hey BB, I don't have experience with these ESCs so I can't really tell you what's going on, but I have a hunch. It may be worth a try. Unplug one of your ESCs and try your tests with just one motor+ESC hooked up.

I have a feeling that the two ESCs might be fighting each other. Some ESCs will play well with each other in a twin setup, and some won't. If my hunch is right and the ESC works perfectly when you only have one of them plugged in, this may be the explanation. I know its not going to solve the problem! But maybe it can clarify what's going on.

If you are using a separate BEC then you need to cut the red wire that is going from the ESC to your throttle input on the receiver. (that wire is sending voltage to the receiver from the ESC, and multiple inputs could be causing this interference.) But don't do that until after you figure out what's going on.

I'm interested in seeing other's opinions, I'm just offering a hunch.

[BBriBro]

Seeking help troubleshooting ESC's. My A-10 was working just fine, but I wanted to have reverse thrust. It's all the rage and I wanted to be unique and have the only TWIN EDF with reverse at the club. I bought 2 Hobbywing FlyFun V5 120A ESCs. (both BECs have been disabled) They are nothing but trouble, I have been through every setting, spoke with HW tech support, Motion RC tech support, and none of their suggestions help. I'm really am at a loss here. I have tried virtually every combination of settings (and several different batteries). (I have also reinstalled the OEM ESCs to rule out a bad motor that just failed during my “upgrade”. And the stock ESC’s work fine).

Motion RC suggested 8 or 12 degrees of timing with normal start up mode, With these settings, the motors will not even accelerate without very violent stuttering. You could slowly accelerate to WOT and they would last for a couple seconds then shut down, but if you just slam the throttle stick forward, you get almost no acceleration, just a stutter and a lock up. I then changed JUST the startup mode to very soft, and that helped a lot, You can jockey the throttle stick as you wish, but again after a couple seconds at WOT they shut down. If you never hit WOT it “seems” ok. But regardless of how you get to WOT, once there for a couple secs, they shut down.

Hobbywing suggested 30 degrees of timing. This actually seemed better (with the very soft start) but still will not allow WOT for more than a couple seconds.

Both Motors will accelerate to full power smoothly, but if you keep it at full throttle for more than a few seconds, you get a couple very large stutters and then the ESC shuts down, if you immediately throttle back, you can “catch it” and then reapply power smoothly, but if you don’t reduce power the ESCs will shut down, no beeping, no nothing, just dead until you disconnect the battery and then it resets.

I'm drawing about 85-90 amps at WOT. I also disabled reverse, to make sure that the motors were spinning the proper direction with the ESC in forward (And not needing the ESC in "reverse" for forward thrust, for whatever difference that makes). To my knowledge forward and reverse are exactly the same, but it was worth a shot.

I'm using a Taranis transmitter with a FrSky X8R receiver. I read the comment about the "Futaba Standard" in the manual for the throttle range. I have calibrated the throttle (several times). I even set the throttle range to exactly match their recommendation of 1100-1940us. (And then recalibrated) That didn’t make a difference either, I’ve never had an ESC care about those settings as long as you calibrate so I switched back to the Taranis defaults of 1000-2000 (and recalibrated again) I'm running the stock motors and fans. It certainly seems like a timing issue with the stuttering and squealing, And of course HW couldn't tell me what was different about the OEM HW ESC vs. the FlyFun V5.

Is it possible that some ESCs are just not compatible with some motors? I felt sure it was just a setting, but after all my troubleshooting I'm beginning to wonder if it's just not going to work?

[Elbee]

TMD, Never gets old, my friend, does it? Great photo, too. BRRRRRRRRRRRRRT, LB

[themudduck]

I have been using RT 6250's (label says 35C) in my A10 for several years and they are 800gms each. I also have some HRB 6000's (label 50C) that weight 830gms each. Both brands test at around 30C and they perform almost identically.

I moved the trays back to balance at around 90, the plane flies great and I can hold the nose up easily during landing.
I balance gear down because I want the plane to fly correctly during takeoff and landing. The CG may change slightly when the gear retracts but it has little affect with the A10. (IMO) I balance all of my planes in this way....

The weight of the batteries is important (also the performance). The more weight you load into any RC plane, the harder the motors have to work and the less flight time you'll have (all things being equal). Light flies better!
Your Admiral 6000's are adding more than half a pound compared to what I am using- My advice is to search for batteries with the highest real (tested) C rating with the lowest weight. The holy grail. SMC's are excellent!

Here's mine.... Brrrrrrt!

[Hugh Wiedman]

Thank you for your practical advice. The battery weight given on the manufacturer's website is 910 g and my weight showed 931 g. For full understanding, I am posting a graphic about CG.

OK then, I'm referring to #4. And that is so strange about the battery weight, I have/had 16 of the Admiral 6000 Pros and they all weighed between 830-836 gr. They must have changed their chemistry in the last year and you are correct, the website lists it closer to 910 g. Noticed the 5000's also went in weight from 702 g to 746 g. Thanks for pointing that out. But I still have to say that at 931 g each for the 6000's, that's way too heavy for that mah of a battery. The SMC 6200's are 814 g each and I guarantee you the IR values are at least as low if not lower than the Admirals. For the A-10 (and my Mig29), that's an extra 234 g of weight, not acceptable IMO.

[Evan D]

Checking balance on the ground is a reference point. You should adjust the CG forward or back depending on how it flies. MY WAY, and there is no right or wrong no matter how opinionated people are, is to do a low wing upside down and a high wing right side up. I do it with gear extended but that's a hold over from wet fuel days.

That said I usually do a quick check once the balance point has been determined in flight by either a quick lift with it sitting on the bench right side up and on it's gear or, on some planes, a tail sit test.

[crxmanpat]

For low wing aircraft, use #4. For high wing, use #2. You always want to measure CG in landing configuration as that is when your model is most sensitive to small changes.

As for the CG of this model, most of us have found that 85-90mm is much better.

[RAFALR30]

Nice Battery Trays, well done! First off, I assume you had a misprint in the weight of the Admiral 6000 Pros, instead of 930g each, mine weighed in at 836g each but don't use them anymore. I'm exclusively using SMC 6200's at 814g each, but that's a different story and not relevant to your question. I always balance my aircraft upside down, gear down (assume that's #4 of your options referred to as "back" position, no?), but others measure gear up (and right side up) so that's a personal preference. I do it with gear down because IMO, that's when you are flying the slowest and want to "know" how it flies during take-off and landing and inverted it is much more "sensitive" on the balance poles so you can really determine the exact mm you're at.

With that said, I balanced mine at 92mm instead of the recommended 78mm (is that right, 78mm per the manual, or am I remembering some other EDF-either way I do remember that I'm at least 15mm further aft from recommended), which I felt was way too nose heavy and made it difficult to make nice slow landings with the nose up eliminating the possibility of the nose gear hitting first causing the dreaded "bucking bronco" that many have suffered causing a lot of damage. In doing the in-flight 45 degree test (full throttle at an up angle of 45 degrees, then go inverted and it should slowly fall back down) that's the point where it fit that profile (at 78mm fell off way too quick). Don't forget that the jet thrust on the A-10 goes directly over the horizontal stabs, so if you have it too nose heavy, which requires more up trim, the jet wash exaggerates that up pressure with more throttle and at lower throttle settings, less up effect, causing this EDF to rise and fall dependent on your throttle setting, unlike any other EDF. For me, at 92mm gear down, trimmed for level flight, it stays level at full throttle or even when cutting the throttle, which tells me it's relatively neutrally balance. At least that's my personal belief, but then I still believe in Santa, the Easter Bunny and honest politicians!

Landings definitely not my strong suit, but you can see from the following video, she flies so sweet and lands like a kitten. (OK, I'm really just looking for a few more views and likes)

Thank you for your practical advice. The battery weight given on the manufacturer's website is 910 g and my weight showed 931 g. For full understanding, I am posting a graphic about CG.

[Hugh Wiedman]

[Hugh Wiedman]

I have big and heavy batteries (Admira Pro 6s, 6000mAh - 930g each) so I had to make new battery holders for a good CG (center of gravity).
How do you measure the CG:
1. model in normal position with the landing gear closed
2. model in normal position with the landing gear open
3. model in the back position with the landing gear closed
4. model in the back position with the landing gear open
I noticed that opening the landing gear made it necessary to move the battery forward almost 2cm.
How is it in your models?

Nice Battery Trays, well done! First off, I assume you had a misprint in the weight of the Admiral 6000 Pros, instead of 930g each, mine weighed in at 836g each but don't use them anymore. I'm exclusively using SMC 6200's at 814g each, but that's a different story and not relevant to your question. I always balance my aircraft upside down, gear down (assume that's #4 of your options referred to as "back" position, no?), but others measure gear up (and right side up) so that's a personal preference. I do it with gear down because IMO, that's when you are flying the slowest and want to "know" how it flies during take-off and landing and inverted it is much more "sensitive" on the balance poles so you can really determine the exact mm you're at.

With that said, I balanced mine at 92mm instead of the recommended 78mm (is that right, 78mm per the manual, or am I remembering some other EDF-either way I do remember that I'm at least 15mm further aft from recommended), which I felt was way too nose heavy and made it difficult to make nice slow landings with the nose up eliminating the possibility of the nose gear hitting first causing the dreaded "bucking bronco" that many have suffered causing a lot of damage. In doing the in-flight 45 degree test (full throttle at an up angle of 45 degrees, then go inverted and it should slowly fall back down) that's the point where it fit that profile (at 78mm fell off way too quick). Don't forget that the jet thrust on the A-10 goes directly over the horizontal stabs, so if you have it too nose heavy, which requires more up trim, the jet wash exaggerates that up pressure with more throttle and at lower throttle settings, less up effect, causing this EDF to rise and fall dependent on your throttle setting, unlike any other EDF. For me, at 92mm gear down, trimmed for level flight, it stays level at full throttle or even when cutting the throttle, which tells me it's relatively neutrally balance. At least that's my personal belief, but then I still believe in Santa, the Easter Bunny and honest politicians!

Landings definitely not my strong suit, but you can see from the following video, she flies so sweet and lands like a kitten. (OK, I'm really just looking for a few more views and likes)

[RAFALR30]

I have big and heavy batteries (Admira Pro 6s, 6000mAh - 930g each) so I had to make new battery holders for a good CG (center of gravity).
How do you measure the CG:
1. model in normal position with the landing gear closed
2. model in normal position with the landing gear open
3. model in the back position with the landing gear closed
4. model in the back position with the landing gear open
I noticed that opening the landing gear made it necessary to move the battery forward almost 2cm.
How is it in your models?

[rkh_78]

Hey all, I simply removed everything with applications of acetone, (90%+ IPA would work, as well). I added 3 coats of semi-gloss Minwax Polycrylic and then foam brushed Behr latex in the peanut colors. Took a while to strip but EPO foam didn't care and the polycrylic puts down a great hard surface. I think it's better than the OEM finish. Anyway, worked for me. Best, LB

AMAZING!!!!

[Elbee]

Outstanding!

[Hugh Wiedman]

Hey all, I simply removed everything with applications of acetone. I added 3 coats of semi-gloss Minwax Polycrylic and then foam brushed Behr latex in the peanut colors. Took a while to strip but EPO foam didn't care and the polycrylic puts down a great hard surface. I think it's better than the OEM finish. Anyway, worked for me. Best, LB

Outstanding Repaint, as usual!

Frank had it right and all I can say is:

[Elbee]

Hey all, I simply removed everything with applications of acetone, (90%+ IPA would work, as well). I added 3 coats of semi-gloss Minwax Polycrylic and then foam brushed Behr latex in the peanut colors. Took a while to strip but EPO foam didn't care and the polycrylic puts down a great hard surface. I think it's better than the OEM finish. Anyway, worked for me. Best, LB