First foam build - Old Fogey - can't get it to fly!

[vihila]

Seems like an issue with the power plant, because looking at your picture and reading through your comments about the weight, it doesn't seem physically far off from what it's supposed to be. The bigger motor seems adequate but there may be something wrong with it or your ESC. 110W at max throttle on a 3S seems a little low. 110W/12V = ~9.2A... I think the Power Pack B motor (EMAX CF2822) pulls around 16A at full throttle, so maybe your motor is a little underpowered, but I think it should still be able to pull it at full throttle.

If calibrating your ESC and running full throttle doesn't work, I would suggest a new motor and/or ESC. You can get the EMAX CF2822 and a 20A ESC from Value Hobby for around $20, or get them from FT for a little more with the convenience of having the bullet and XT60 connectors already soldered on.

Also, make sure you don't have any strange limits, subtrim, rates, expo, etc. set up on the throttle channel on your transmitter. Maybe do a reset for the settings on your model and rebind it just to make sure.

Sometimes the ESC can get accidentally programmed the wrong way too. I would suggest looking up the manual for it and seeing if you can program a factory defaults reset. For example, I accidentally changed something called the "timing mode" on one of my 12A EMAX ESC's and it was exhibiting really weird behavior. I went through each one of the programming options and set it to default until I found resetting the "timing mode" fixed the issue.

Good luck!

 

[kdobson83]

Ok, back to the thrust thing. Forget about watts and all that. Too many variables in my opinion. My setup puts out 400-450 grams of thrust. U said u think yours does about 300. That's over 25% less. Mine climbs at about 3/4 throttle. Which means yours would have trouble just staying afloat. I would imagine we are comparable in weight, if anything you being heavier since your using a bigger MAH battery, and I'm not sure if the FT WR foam is heavier than the regular DTFB white stuff.
So, my conclusion, you don't have enough thrust. Either the motor is damaged/weak with age/or just not enough power. Get a more powerful motor on it. You can try increasing your elevator throw but I doubt that'll help. I seriously doubt it's the plane at this point, you seem to have checked everything.

Bigger motor and itll fly, I'll put money on it. Oh, and be careful, the Old Fogey HATES wind. The slightest tinkle of wind 2-3mph, was throwing me around. This plane is like a giant light weight wind sock.

 

[TEAJR66]

Unless I have missed something, you are overweight and over propped.

For a 3S battery, that motor should probably have about a 7" prop. Then, a 1300mah battery is way to big. I would not go larger than a 1000mah battery and know that it will have to fly fast at that weight. A 500mah-850mah battery is more appropriate. Realizing that the Old Fogey advertisement says that a 1300mah 3S is acceptable, keep in mind that is the upper limit with the recommended motor and prop.

Your motor is about twice the weight of the recommended "B" pack motor.

All and all, it sounds like you are overweight for the airframe. Even if you get the power worked out, you will not get the flight characteristics you are looking for. Again, sticking with a 500mah-850mah 2S or 3S battery will get you closer to the desired flight characteristics.

I recommend that you pick up a B power pack and give it a try. For every thing that comes in that setup, FT has them at a good price.

If you don't want to spring for the whole power pack, places like this have the motor and ESC that should work. You will also need to provide the battery plug for the ESC.

Let us know what you end up doing and if there is anything else we can help with. I hope you get this sorted and find some joy.

 

[petergaultney]

TEAJR66 - thanks for stopping by. I'm hoping to test a couple of things later this afternoon, as the wind yesterday was far too high to fly. I'm planning to report back.

However, while I may be overpropped, I'm confident I'm not over weight. The website says the Old Fogey's weight before battery should be 13.3 ounces, and I'm right at 14 ounces. My batteries get me up to 17 ounces, and while that's possibly a little on the heavy side, it shouldn't be acting like it does without something wrong in the powertrain.

Also, I have tried a 25gram motor with a small 2S battery, which are both more-or-less what the website recommends. I only went up to the heavier motor because I wasn't getting nearly enough power out of the low-powered setup. But my current motor weighs only 50 grams, and the EMAX CF2822 that comes with Power Pack B only weighs 10 grams less than that, so it's certainly not double what's recommended.

Among other things I'm hoping to test this evening, I'll try to give a smaller prop a try. Unfortunately I don't have any 7 inch props - I have some cheapo 8x6s, but those have a higher pitch than I'd really prefer.

 

[makattack]

I haven't seen you verify that you've been able to get a ESC throttle range calibration done, but failing to do that wouldn't leave you with hot motors either, unless you're over propped.

Don't forget that it's not just the diameter of the prop disk to watch for, but also the pitch and shape. I don't really see really detailed pictures from what you posted of the props as mounted on your plane, but those kind of look like Slow Fly props, which aren't meant to be spun at a high RPM -- so a higher KV motor wouldn't be the answer unless you want the props to flutter / cavitate / high speed stall whatever the term is. They seem like pretty high pitch props... you mentioned 9x4.7 & 8x6 -- not super high pitch, but as an example, I wouldn't fly a 9x4.7 slowfly prop on a 25g "blue wonder" style motor on 3S... I would only dare use 2S / 7.4V on that.

I would say that the 8x6 prop is probably equivalent to the 9x4.7 -- so... yah, might be appropriate on the bigger motor, but not the small one.

While you said you're pretty sure the props are on correctly, generating trust in the right direction, my question is: is it a quiet thrust? You can (and I have) mount props in reverse and still generate thrust in the right direction, only it's super draggy and will generate much less thrust than if they were mounted correctly. They'll be much louder at the same throttle, and sound impressive, but will be less powerful. That would explain lack of thrust / high heat & power usage. Thrust direction is really about the motor spin direction, while correct prop mounting determines if it's efficient or not.

 

[petergaultney]

ESC throttle range has been calibrated according to the instructions I received in this thread, though it didn't seem to alter the measurements coming from the watt meter. Technically, my ESC never beeped at full throttle - just sat there quietly instead of initializing like normal. But I assume that's just the way this particular one works.

What you say about slowfly props is really helpful - I've read as much as I've found about props, but I hadn't run across that piece of information before.

Yeah, the props are definitely facing forward. The logo is on the front, as are the numbers, and it's also just like looking at a fan blade. With the motor spinning CCW, it's very easy to verify that the shape of the airfoil is 'pointing' in the correct direction. Still, I appreciate you suggesting this - it's not an unreasonable thing to suspect.

 

[makattack]

Well, throttle range setting via TX sticks is not a set standard. It's really about what the software driving the esc implements. Some esc's don't have a stick throttle range calibration mode or uses a different sequence. I have one esc that doesn't arm until you power up at zero, raise throttle to max then reduce. Try to look up the manufacturer of the esc for the manual.

This rpm limit table from apc might help:

https://www.apcprop.com/Articles.asp?ID=255

 

[petergaultney]

My ESC is apparently a E-Flite EFLA7320. http://www.e-fliterc.com/Products/Default.aspx?ProdID=EFLA7320 isn't very helpful, but I found the Ascent 450 page, which links to some instructions about the ESC that came with it, which was this one.

Turns out this is a 3S-only ESC! And it has a low voltage cutoff. Which completely explains why the 2S never worked (well) with this ESC - the motor was running, but not at full power.

I have a different ESC (a Turnigy AE-30A) that should be good for 2-4S batteries, so I'm going to use that one here in a bit when I try to fly the plane again.

Unfortunately this doesn't explain why my attempts to fly this weekend on a 3S didn't have enough power. But I'm about to test the plane anyway and we'll see what happens with a 3S and a 2S (though I think this motor will be underpowered on a 2S).

 

[makattack]

This appears to be the manual, using my Google-fu skills

https://www.google.com/url?sa=t&sou...yIZ_d5F6-pf5yIT0A&sig2=K-hrOys-LbtzTx-0LZGxLw

Indeed, it has a slightly weird throttle calibration method involving a few cycles of max and min throws. That might explain the 3s issues.

 

[petergaultney]

I ran out of time last night waiting for this video to process. And I'll report further later today when I get a chance. But here's the results of last night's test...

http://photos.petergaultney.com/Old-Fogey/n-SsVrRL/i-Jsj2m7h

 

[petergaultney]

So the report is that it flies! For proof, see the video in the previous post.

I suspect, but cannot prove, that my prop mount simply wasn't working as well as I thought. In my previous attempts at flight, the propeller was definitely rotating, but perhaps it wasn't as secure as I thought, and therefore wasn't producing the full thrust it should have.

Regardless, the plane definitely flies! It exhibits some of the adverse characteristics that others have reported - there's a bit of dutch-roll-like tendency, and also a tendency to want to fly tail-down despite being actually a bit nose-heavy. Reducing the angle of incidence of the main wing is a commonly-suggested tactic for ameliorating this issue, and making the vertical stabilizer larger/taller is a common suggestion for giving the plane more lateral stability. I hope to experiment with both of those at some point.

I did try running the plane with a 2S on the same (1000kv) motor, and as I expected, that didn't work. There just isn't enough power. I'm cautiously hopeful that going to the faster (1400kv) motor on the 2S might give it just enough power to keep itself in the air, and I'm going to experiment with that the next time the winds look good enough to fly. I'd like to see the plane happier at slower speeds, and if I could get my hands on a smaller 2S than the 1250mah that I have, I might be able to cut a total of 75 grams - down to 425 from 500.

I looked at that guide about rpm limits for APC-style slowfly props. Frankly, I find 65000/(prop diameter in inches) a little unrealistic - a 1400kv motor even on a 2S at 8V will spin at 11200rpm, and according to their guide you'd have to run a sub-6-inch prop to be under that limit. I have a hard time believing that a 5.5 inch prop would even pull this plane through the air. Nevertheless, it definitely explains why, at 12V on a 1000kv motor, I start getting prop whine in the top quarter of the throttle range. Their suggested limit for a 9 inch prop is 7200rpm, and I'm spinning the prop up to 12000rpm at wide open throttle.

If anyone has any other thoughts based on what you see in the video, I'm all ears! It's really satisfying to get this plane in the air, and I'm looking forward to experimenting further to perfect it!

 

[makattack]

Nice going! Great to hear you were able to sort out the issues in a methodical way to see success.

I might recommend, based on your first post, if you were looking at a nice, park flyer with better flight characteristics compared to the Fogey, one of the high wing trainer type planes like the FT Storch, FT Explorer, or even the FT Bushwacker.

If you're looking for a quicker build, and don't mind the bank and yank style, I find the FT-22 is great in a small park setting.

 

[petergaultney]

Thanks!

We're definitely looking for a nice park flyer, and the Storch is on our list. But I prefer planes that can be flown in as small a space as possible, and the Fogey is probably superior to the Storch in that regard from what I can tell? Maybe not as easy to control, but happier at slower speeds in any case. The Bushwacker looks like I'd love it, but it sounds like it's probably even less beginner-friendly than the Old Fogey, and part of the reason I want slow is so that I can hand my controller over to people who haven't ever flown before.

I've heard that the Tiny Trainer might be a good slow-flying beginner plane to try out as well?

 

[kdobson83]

The tiny trainer is awesome!! I built mine with the 3 channel wing first, using a 500mah 3s on A-pack motor with 6030 props, it almost goes backwards in a light breeze. As I got more confident, I moved to the sport wing and put a 6045 prop on it and it's a rocket but still slows down for easy landings. I have crashed many times and with slight repairs it is still flying 1 1/2 years after maiden. I even put a bomb drop on it and was dropping paratroopers out for my kids to chase. Here's a video of that.
https://youtu.be/CsiRvB_2x1c
And here's a video of how slow the Fogey can go in calm conditions, zero wind.
https://youtu.be/4yDBbcSDzWk
Both good planes but I have to say I like the Tiny Trainer a lot more due to its versatility and performance.

Anyway, glad to see another soul sucked into this hobby as I have. Enjoy it!!

 

[Henry]

Check this guys videos of his Storch. Looks like a perfect park flyer.

https://www.youtube.com/watch?v=8QiEKUJsvww

 

[Hai-Lee]

The TT is awesome and should you want it to fly even slower then look at a different build wing if you do not mind cutting your own parts.

Check out either of the following threads"

http://forum.flitetest.com/showthread.php?31082-Looking-for-a-slow-Park-flyer-FT-build

http://forum.flitetest.com/showthread.php?33350-Building-Hai-Lee-s-Tiny-Trainer-Slow-Wing

Have fun!

 

[TrentC]

Is it painted?

 

[nhk750]

The Tiny Trainer is my go too plane for walking out the back door to the nearby football field to fly after work. It is a great small space plane. I have the 4 channel setup and it is pretty fast, so I need to be careful in the small field, but it is great for practice! This video is at my local RC club.

 

[ViperTech]

I watched the video and it seems to fly ok but there is something wrong in the motor/ prop department, sounds out of balance or it is spinning the wrong way, I just skimmed thru the post and I see where you state the label /numbers/ print is forward on the prop but could you have a pusher prop or right handed prop? The noise is just wrong from the motor to my ears. Is the motor mount secure? I had a balance problem on my Dynam Blue Devil Bi-plane that turned out to be the prop adaptor.
Are you using a prop saver setup?

 

[petergaultney]

I watched the video and it seems to fly ok but there is something wrong in the motor/ prop department, sounds out of balance or it is spinning the wrong way, I just skimmed thru the post and I see where you state the label /numbers/ print is forward on the prop but could you have a pusher prop or right handed prop? The noise is just wrong from the motor to my ears. Is the motor mount secure? I had a balance problem on my Dynam Blue Devil Bi-plane that turned out to be the prop adaptor.
Are you using a prop saver setup?

I agree that things aren't quite right with the prop. The motor mount is quite solid, and it's a CCW prop - it's definitely facing the right way. I know what a prop airfoil is supposed to look like and how it works, so I'm quite confident on that front.

However, I am using a prop saver, as mentioned in my first post, and I've never been 100% happy with how it mounts. The props come with plastic ring adapters to fit different diameter shafts, but unfortunately the base of my prop saver's tapered cone isn't the same size as any of those ring adapters. So I have no choice but to mount the prop against the tapered cone itself. Now, supposedly, this should be fine - or at least so I've read on the Internet here. But I don't feel confident that my prop is sitting perfectly perpendicular to the shaft. And I suspect that it may be vibrating due to that.

It seems that I just haven't figured out the art of mounting props. I'll continue to experiment with different setups, and I'm disappointed that there doesn't seem to be a simple standard that the industry/community has settled on... but at least it's mounted well enough to fly!