What did you crash today

[Burnhard]

@Burnhard - I was recently smitten by the RCGroups profile/skin plane thread and was noticing you had 3 in your avatar. Are they recent and I was wondering if you used Adams readyboard.

I did these as a side job last year while I was doing the MS Mustang. I am not living in the US so I do not have access to the exact FT material (I do sometimes order a SBK from FT but with shipping and customs that‘s hardly feasible). The foam board I use is just standard hobby grade foam board. I did a build review on the FT page.

 

[Inq]

I got off lucky.

1st Flight went so-so.

The Good

• It got off the ground in about 30 feet.
• It didn't need any corrections for balance which was my biggest concern. Being such a rookie, I'm leery of the plane being uncorrectable (at least... by me). I didn't need any trimming while flying.
• I wanted to explore the Flaperon version. I got all the mixes working and it actually did slow the plane down for landing.
• I did get it on the ground without harm.

The Bad

• Clarity of Instructions (or hearing what I wanted to hear) - I went through the build, review, flight videos multiple times. There is conflicting information, but it is definitely my fault in interpretation. The plans have adjustment gauges for 20° and 27° for low and high rates, yet the title page says 12°. I set all my surfaces to the 20°.
• The ailerons (especially since I didn't heed the "for advanced flyers" warning) were WAY too aggressive.
• It seems way to underpowered. I could barely climb. I really had to nurse the elevator and finally got it to about 100 feet. There is no way it could have done the stunts shown in the videos. I'm using a a2212 1000 Kv motor, 30A ESC and 10x4.5 propeller. This is a commodity kit that only costs $18. It stalls very easily when pulling back on the elevator. Even if I plateau to speed up, it doesn't seem to have enough power to really speed up.

2nd Flight, not so, so-so...
For the second flight, I upped the aileron exponential to 60%. This didn't seem to improve the touchiness to any great degree. I had scare out at about the limits of the field... say about 300 yards where I lost perspective of its orientation, got into a spin and pulled it out with only feet to spare. There were many indrawn breaths from the club's peanut gallery that typically are unmerciful to each other. I think they're giving me a grace period since I'm new AND green. As I slowly got it back nearer there were a few comments saying, "thought we were in for a recovery hike."

Trying to get it on the ground, the adrenalin was too rich and I overcorrected with the help with the aggressive ailerons, cartwheeled and nose planted. The damage is surprisingly light, but it tore off the forward facing skewers for the power pod and the firewall from the power pod and broke the prop.

I decided to think about what I learned and NOT do a field repair. A third flight might end even bigger. I'll get back up on that horse another day. Things I've decided to do before flight 3...

1. I'll disconnect the flap portion from the flaperons and just do ailerons.
2. I noted on several of the club's planes that the ailerons were far smaller. An Ugly Stik, even though having full length, strip ailerons, they were only about 20% the size of these monsters. I'm also going to reduce the size of the ailerons. Probably just cut the trailing portion right at the offset.
3. The rudder became delaminated somewhere. Don't know if it was the crash or simply the rudder drags the ground. My skid was too short. I'm going to add a steerable tail wheel. I'd like to be able to taxi in/out nice and proper-like.
4. I didn't like my battery mounting method and since my power pod is damaged anyway, I think I'll re-do a front-end for the plane. Weather here is suppose to be rainy for the next ten days anyway, so I have plenty of time to re-design. Possibly do a 3D printed front-end.

 

[Off-topic jes]

Here we are, as good as new. Decided to go for a new nose. View attachment 221544

Do these fly well?

 

[Burnhard]

Do these fly well?

It’s really my favorite trainer aircraft. What I like is that it comes with a lot of options. You can do flaps on it. The large wheels are very helpful on our grass field (the typical 6/7cm scale wheels are a bit small for our field). Transport is easy as well as the wing is removable. Upgraded the motor two months ago and she can now go vertical. She has gone through so much beating and still flies great.

 

[Burnhard]

I got off lucky.

1st Flight went so-so.

The Good

• It got off the ground in about 30 feet.
• It didn't need any corrections for balance which was my biggest concern. Being such a rookie, I'm leery of the plane being uncorrectable (at least... by me). I didn't need any trimming while flying.
• I wanted to explore the Flaperon version. I got all the mixes working and it actually did slow the plane down for landing.
• I did get it on the ground without harm.

The Bad

• Clarity of Instructions (or hearing what I wanted to hear) - I went through the build, review, flight videos multiple times. There is conflicting information, but it is definitely my fault in interpretation. The plans have adjustment gauges for 20° and 27° for low and high rates, yet the title page says 12°. I set all my surfaces to the 20°.
• The ailerons (especially since I didn't heed the "for advanced flyers" warning) were WAY too aggressive.
• It seems way to underpowered. I could barely climb. I really had to nurse the elevator and finally got it to about 100 feet. There is no way it could have done the stunts shown in the videos. I'm using a a2212 1000 Kv motor, 30A ESC and 10x4.5 propeller. This is a commodity kit that only costs $18. It stalls very easily when pulling back on the elevator. Even if I plateau to speed up, it doesn't seem to have enough power to really speed up.

2nd Flight, not so, so-so...
For the second flight, I upped the aileron exponential to 60%. This didn't seem to improve the touchiness to any great degree. I had scare out at about the limits of the field... say about 300 yards where I lost perspective of its orientation, got into a spin and pulled it out with only feet to spare. There were many indrawn breaths from the club's peanut gallery that typically are unmerciful to each other. I think they're giving me a grace period since I'm new AND green. As I slowly got it back nearer there were a few comments saying, "thought we were in for a recovery hike."

Trying to get it on the ground, the adrenalin was too rich and I overcorrected with the help with the aggressive ailerons, cartwheeled and nose planted. The damage is surprisingly light, but it tore off the forward facing skewers for the power pod and the firewall from the power pod and broke the prop.

I decided to think about what I learned and NOT do a field repair. A third flight might end even bigger. I'll get back up on that horse another day. Things I've decided to do before flight 3...

1. I'll disconnect the flap portion from the flaperons and just do ailerons.
2. I noted on several of the club's planes that the ailerons were far smaller. An Ugly Stik, even though having full length, strip ailerons, they were only about 20% the size of these monsters. I'm also going to reduce the size of the ailerons. Probably just cut the trailing portion right at the offset.
3. The rudder became delaminated somewhere. Don't know if it was the crash or simply the rudder drags the ground. My skid was too short. I'm going to add a steerable tail wheel. I'd like to be able to taxi in/out nice and proper-like.
4. I didn't like my battery mounting method and since my power pod is damaged anyway, I think I'll re-do a front-end for the plane. Weather here is suppose to be rainy for the next ten days anyway, so I have plenty of time to re-design. Possibly do a 3D printed front-end.

View attachment 232653

Do you fly on 2S or 3S?

 

[Inq]

Do you fly on 2S or 3S?

It's 3S. But I didn't know the ESC could be calibrated and I might not be developing full power. I happen to have a watt meter and tachometer ordered and I want to check it before/after calibrating. My biggest trouble was thinking... I could handle the full span flaperons. Way too touchy for me starting out. I'm still debating about getting a bigger motor though. Sounds like the A2217 should be able to go vertical whereas my A2212 can barely go up.

How big a motor did you upgrade to?

 

[Off-topic jes]

It’s really my favorite trainer aircraft. What I like is that it comes with a lot of options. You can do flaps on it. The large wheels are very helpful on our grass field (the typical 6/7cm scale wheels are a bit small for our field). Transport is easy as well as the wing is removable. Upgraded the motor two months ago and she can now go vertical. She has gone through so much beating and still flies great. View attachment 232678

Did Taildragger design that?

 

[Burnhard]

Did Taildragger design that?

I believe the original design is from Peter Sripol.

 

[Burnhard]

It's 3S. But I didn't know the ESC could be calibrated and I might not be developing full power. I happen to have a watt meter and tachometer ordered and I want to check it before/after calibrating. My biggest trouble was thinking... I could handle the full span flaperons. Way too touchy for me starting out. I'm still debating about getting a bigger motor though. Sounds like the A2217 should be able to go vertical whereas my A2212 can barely go up.

How big a motor did you upgrade to?

I believe your motor gives you a maximum of some 800 grams of thrust in your current set-up. That‘s probably a bit low.

My Frankenwacker flies on a 1130 kv motor with a diameter of 35mm and a weight of some 170g. The motor is labelled for 1.3kg 3d planes up to 2.5kg trainers. The all-up weight is below 1kg.

 

[WillL84]

It's 3S. But I didn't know the ESC could be calibrated and I might not be developing full power.

Yea that kinda info would be REALLY helpful in the build videos. For my legacy there was nothing on that. Then because I went with the twin motor rather than the single there was a TON of info in the video for the single motor that was also relevant but left out of the dual motor video. I actually found out about syncing and calibrating the ESC's from someone's post here. I always though it was funny that one motor would start before the other.

 

[Inq]

I believe your motor gives you a maximum of some 800 grams of thrust in your current set-up. That‘s probably a bit low.

My Frankenwacker flies on a 1130 kv motor with a diameter of 35mm and a weight of some 170g. The motor is labelled for 1.3kg 3d planes up to 2.5kg trainers. The all-up weight is below 1kg.

I'm still wrapping my head around the concept that a scale planes needs so much more power relative to their weight. Just checked a Cessna 172 has 0.23 thrust to weight, but here I'm needing more than 1.0 for a trainer. My Storch trainer's all-up weight with the 2200 mAhr battery is 884 grams. Before flying it, I would have thought 800 grams of thrust would be overpowering... and nearly able to go vertical. Seeing the dog fly... I'd say, "Let's bring on some real power!"

 

[Piotrsko]

To go vertical you would need more than 884 grams thrust; perhaps 10% more minimum because to fly vertical you still need to accelerate from zero forward speed. Ditto for horizontal, but at some point you start flying so the rolling loads fall off but drag increases @ speed squared. Model scale.is bunches draggier that full scale.

A full size cessna operates in a different series of regimens. IIRC, you need 1,000 ft runway to do a short soft field take off. Maybe 100ft for this scale and asphalt, not mowed grass, less if you make more thrust. The suggested throws are different from maximum throws and expo just makes the servo response a dampened curve proportional to stick throw.(mellows out the response at center but still allows a save it deflection at edges)

 

[Off-topic jes]

I believe the original design is from Peter Sripol.

Oh right

 

[Burnhard]

To go vertical you would need more than 884 grams thrust; perhaps 10% more minimum because to fly vertical you still need to accelerate from zero forward speed. Ditto for horizontal, but at some point you start flying so the rolling loads fall off but drag increases @ speed squared. Model scale.is bunches draggier that full scale.

A full size cessna operates in a different series of regimens. IIRC, you need 1,000 ft runway to do a short soft field take off. Maybe 100ft for this scale and asphalt, not mowed grass, less if you make more thrust. The suggested throws are different from maximum throws and expo just makes the servo response a dampened curve proportional to stick throw.(mellows out the response at center but still allows a save it deflection at edges)

The 10% more is probably still to low. Another thing to note, you will not get full thrust over the full flight time. After the first minute or so, your battery will give you less volts. The numbers advertised are usual for perfect test environments. In real life you will also have things like wind etc, that will have an impact.

 

[Inq]

I believe your motor gives you a maximum of some 800 grams of thrust in your current set-up. That‘s probably a bit low.

My Frankenwacker flies on a 1130 kv motor with a diameter of 35mm and a weight of some 170g. The motor is labelled for 1.3kg 3d planes up to 2.5kg trainers. The all-up weight is below 1kg.

Got my Load Cell equipment and printed some parts... https://forum.flitetest.com/index.php?threads/diy-motor-dynamometer.71186/#post-735947

I checked my configuration as it flew that day and got thrust at max throttle:

• A2212/13T 1000 KV
• 10x4.5 Prop
• 11.38V
• 9.22A
• 6220 rpm
• Thrust = 584 grams

Calibrated it per your instructions and am now getting:

• 11.35V
• 14.12A
• 7020 rpm
• Thrust = 722 grams

Hopefully, I'll get a better response next flight... maybe a little climbing, but I'm debating about my next BIGGER motor. I'd like to get one that I can use on a war bird eventually. I'm looking at this one... https://www.amazon.com/dp/B08LN1MJ7X/?tag=lstir-20 I can fly it with 3S with this trainer, but run it all the way up to 6S and 530 watts for an eventual warbird. Is this logic sound?

I'm also assuming that I have to calibrate for any new combination of ESC and motor? Is that also right?

 

[Bricks]

The motor you link

Got my Load Cell equipment and printed some parts... https://forum.flitetest.com/index.php?threads/diy-motor-dynamometer.71186/#post-735947

I checked my configuration as it flew that day and got thrust at max throttle:

• A2212/13T 1000 KV
• 10x4.5 Prop
• 11.38V
• 9.22A
• 6220 rpm
• Thrust = 584 grams

Calibrated it per your instructions and am now getting:

• 11.35V
• 14.12A
• 7020 rpm
• Thrust = 722 grams

Hopefully, I'll get a better response next flight... maybe a little climbing, but I'm debating about my next BIGGER motor. I'd like to get one that I can use on a war bird eventually. I'm looking at this one... https://www.amazon.com/dp/B08LN1MJ7X/?tag=lstir-20 I can fly it with 3S with this trainer, but run it all the way up to 6S and 530 watts for an eventual warbird. Is this logic sound?

I'm also assuming that I have to calibrate for any new combination of ESC and motor? Is that also right?

For ease of mounting in a plane buy motors that have an X type of mount.. Do you realize just how big that motor is at 42 mm?

Had a total melt down brain fart sorry about that.

 

[Tench745]

The motor you linked is for multirotor use only as there is no signal wire for controlling throttle, and for ease of mounting in a plane buy motors that have an X type of mount.. Do you realize just how big that motor is at 42 mm?

Bricks, I don't understand what you mean by "...there is no signal wire for controlling throttle..." It's a brushless motor; it has a wire for each of the 3 phases like any other brushless motor. Perhaps you're thinking of RC car motors that have an extra sensor to help the ESC set timing?

Multirotor motors work fine in airplanes. Yeah, it's big around, but it's thin; it's a pancake style motor. You can get more torque out of larger diameter motors like this, but it's a large enough diameter, you may have trouble fitting it into any FT designs without modificaitons or making it look really goofy.

Yeah, it's different than the standard "can" style outrunner we're all used to, and I do prefer something with an X mount like Bricks suggests. But if the specs match what you need and you can fit it, there's no reason not to use a "multirotor" motor. I actually just bought something very similar for my next project and FoamyDM used one one his 1/6 scale Floh.

 

[Inq]

I'm new to this electric planes thing. I have a half dozen of the cheap, 2212 in different KV flavors, so I'm not familiar with any other mounting system. Is it that different? Looking at the back picture on Amazon for that motor had 4 holes that I was assuming was the same pattern I'm used to.

That motor was the high-performance recommendation for 3D kit plans I have - https://3dlabprint.com/shop/focke-wulf-ta152h/ I was taking their advice. Is it not a good choice?

Oh! and yes... I know what 42 mm looks like. It's less than 8 inches!

 

[Tench745]

I'm new to this electric planes thing. I have a half dozen of the cheap, 2212 in different KV flavors, so I'm not familiar with any other mounting system. Is it that different? Looking at the back picture on Amazon for that motor had 4 holes that I was assuming was the same pattern I'm used to.

That motor was the high-performance recommendation for 3D kit plans I have - https://3dlabprint.com/shop/focke-wulf-ta152h/ I was taking their advice. Is it not a good choice?

Oh! and yes... I know what 42 mm looks like. It's less than 8 inches!

So, the only difference with an x-mount motor is the little x-shaped bracket that is wider than the motor itself.

The bracket screws to the back of the motor and then you screw the bracket onto the firewall. Without the x-mount you need access to the back of the firewall to screw through the firewall directly into the motor. That's all; neither style is inherently better or worse.

I see no reason not to go with the motor 3D lab print suggests, so long as it meets the criteria for your setup. (voltage, amperage, thrust, prop size, etc). I don't remember what plane you said this is for, was it the Storch?

 

[Foamforce]

Before and after. I finally finished my Guinea Pig. I got up early to try it out this morning. It took off beautifully. Very stable. Flew great for about ten seconds when my signal alarm started beeping, but I already had no control.

It banked slowly left and plowed into the ground from about 50 feet with the motors running. It took me most of the morning to get my sense of humor back. Surprisingly, it’s fixable. The nose is wrecked, but the body only received minor damage where the prop cut into it. The wing got bent at the tip, a rip in the trailing edge from the rubber band, and one of the nacelle pods needs to be replaced. All in all though, not terrible for a powered augering into the ground.

I’m not sure what caused the loss of signal. The motors were still running and I got signal again when I got closer so I don’t think it was a brownout. I had my antennae at 90 degree angles, one pointing backwards and one pointing downwards. Possible my battery cable was touching the antenna and affecting it? Alternately, I’ve seen a couple cases where when a I initially turn on my FlySky Radio I have an inexplicably bad signal. The I turn it off and in again and have a perfect signal.

The only lesson here is to not neglect the range check. Time to rebuild.