gwright

I need to take a digital picture to post,.. haven't done that yet,.. but thought I'd share this with y'all. Seems you're all having too much fun with the PBF's. I was headed up to a large electric event last week, and decided to build an e-powered one to take along. Not having quick access to coroplast around here, I used foam-cor board. Made it 24"X24" with 4" elevons,.. a 7"X7" fin/rudder (yes, a bit larger, as with the electric power setup I planned on using,.. I'd use a very large prop). I glued, then taped-over a 3/16" dowel across the leading edge,. glued on a length of dave-brown fiberglass pushrod on the bottom, added a bit of lite-ply with a couple triangle stock pieces for a motor mount (strapping tape motor/gearbox on that), and viola' . I picked up the foamcor at about 10 minutes after 5 on the way home last wednesday, and test flew at 7:45 at a schoolyard nearby. Weighs 44 ounces with a 10-cell 3000mah pack on board (oh, I have a single wheel on a 5/32" wire leg under motor to protect prop/gearbox). The endoplasma, geared 4.6 to 1, on 10 cells, spins a 12X8 APC electric prop at 7600 rpms, making a bit over 60 ounces of thrust, so hover, then unlimited vertical is at well below full throttle. Flying it like you should fly a PBF (very low throttle most of the time,.. it goes just over 10 minutes with the 3000's. I did find out it will get into and out of a flat spin without too much trouble,..but inverted flat spins go all the way to the ground no matter what I do . Since it's foamboard,.. takes a couple minutes with odorless CA and a couple popsickle sticks to fix the fin/rudder each time I do an inverted flat spin . Since I have a lot more power than the FP40 with a 10X4/10X5 that is commonly used, I was worried about blowing it appart,.. but I haven't yet. For shorter, "high adrenaline flights", a 10-cell CP1300 pack is used (about 4 minute flights), and the weight is down in the low 30's so it gets to almost 2 to 1 thrust to weight. With the larger pack, I can prop down to an 11X7 or 12X6 and get 14~15 minute flights, but it's only at about 1 to 1 thrust to weight then.

Craig-RCU

Gwright,
That sounds like a great setup you have. I'd love to see some videos of your CP1300 pack flights.

I have been able to get out of inverted flat spins with full down elevator and full throttle. I've tried full up elevator with no success. I get too confused about correct rudder inputs in an inverted flatspin so I just leave the rudder alone. Good luck.

A10FLYR

My Feedback: (1)

[QUOTE]
We are enjoying it, thank you for the idea. It is a particularly good plane for me because my eyesight is not good. I have Ocular Albinism. My eyesight is about 20/80 or so, and the PBF is perfect for me. I have a special visual aid that allows me to fly, but I don't need it with the PBF.

Thank you for giving me the PBF, you don't know how much you have given me.

Thanks!

**************************************************

Ain't this a great hobby??

I have met MORE great people thru this hobby than any other medium....... :thumbup: :thumbup:

Foamguy

LOL Oh great ! Gary Wright is in on it now too. Designer/manufacturer of the most excellent E3D. I say this cuz I fly a lot with Paul Susbauer who has his E3D doing stuff most of us glow funfly doods cant do. Now I have a feeling Paul will show up with a PBF. I love this hobby !

The Foamguy

Foamguy

Dustin,

Just out of curiosity, were you a full scale Hog pilot ? Now THAT's an airplane.

The Foamguy

Steven Sloan

Met Dave last night and flew his PBF, way to cool I'm starting on mine today. I hope to be practicing by this evening! A small note about Dusty, being from a smaller town I have know Dusty and his brothers for a long time and have had the pleasure of calling them friends. I owe Dusty a lot for all the help he has giving me in the past. He is the one that taught me how to fly many years ago. We spent many hours tied together by a buddy cord. Where I am going with this story is its not only amazing that Dusty flies so well with his vision disorder and the head gear vision aids that it takes to do so, but he has the ability to teach also.
Thanks Dusty,
Steve

Scorch

No, I'm not a full scale pilot. I've had "low vision" since birth. I have only fown a couple of times, and don't like it. It's fun fly R/C and video games, but full scale, no. Too scary.

Scorch

Steve, that is very kind. Thanks. I learned a lot from you too. That is the best part of teaching someone something you know. You learn more than the "student".

Thanks.

Dave McDonald

My Feedback: (19)

Foamguy,
Glad to see you posting again in the PBF thread!
Your "Squareplane" brainstorm has evolved into my favorite plane! For the past couple of months, about all I ever bother to fly is my PBF. I LOVE this thing!!!

Steve,
Congratulations on your PBF's successful test flight! I'll bring a MCP with me to the field tomorrow to see if we can get some more power out of your MDS 28.

Scorch,
Are you coming to fly at Eldon on Sunday?


Here's my latest PBF. It's powered by a TT 42GP with a MCP, spinning a 10x4 MA prop. The radio was arranged to clear the MCP by laying the throttle servo behind the tank, then attaching the rudder servo on top of the throttle servo. The elevon servos were mounted upright to keep them as close to the center as possible.

Airborne uses a Futaba 127DF rx, 270mah 4.8 volt battery, Futaba S-128 on throttle, Futaba S-132H high speed BB servos on elevons and rudder. Dry weight is 2 lbs, 6 ounces. The long white stripes are Velcro so I can rearrange the receiver and battery to change the CG, which is now at 5.75" back from the leading edge.

The TT 42GP with the MCP runs and throttles just as well as the OS 40FP, but has considerably more power. Vertical acceleration from a hover or torque roll is unreal, and it easily powers it's way through high drag maneuvering. This PBF with the TT 42GP and MCP is fast becoming my favorite of the three PBFs I currently have flying......(Webra 32 PBF, OS 40FP PBF, and TT 42GP w/MCP PBF.)

Scorch

Yes, I will be there. Thanks for the props.

Dave McDonald

My Feedback: (19)

Scorch,
Don't worry about the props. We'll find you some somehow. In fact, a 10x6 will work OK in a pinch. Just grab your PBF and come on down to Eldon!

Scorch

I have lots of 10 x 6! Good. I'm worried about the 270 pack. Would I just charge that for half the time I would the 600mah off the OEM charger? I don't want to burn it up.

Thanks again.

With that in mind, I am going to order 10 or so of those from Hobby Lobby. I will proably break all the MA I have before they get here though


I'll bring my camera too.

Dave McDonald

My Feedback: (19)

I don't recommend charging your 270 battery from your OEM charger. You will probably burn it up. You could add a resistor in series with your OEM charger to bring the charge rate down to about 25 ma. I'll talk to you at the field about how to do it.

Anyway, I can charge battery at the field, so that isn't really a problem for tomorrow.

Before you order a bunch of 10x6 props, keep in mind that they definitely won't work as well as the 10x4 on your 40FP. You might be better off waiting until the 10x4 props are back in stock.

Scorch

Yes, please tell me how to modify the charger at the field..

I actually meant the soft Kavan (spelling?) 10 x 4's not 10 x 6.

Looking forward to today. Will be fun.

Fil-Dill

Dave I found a new gp 42. Do you think I can start without the msp.I like the velcro idea until i fingure out where the cg is.

Dave McDonald

My Feedback: (19)

Fil-Dill,
The TT 42GP should work just fine with the stock muffler. You can always add a MCP later if you want more power.

Can you and Mitch come down and fly with us today?

Fil-Dill

I can't .I have alot of charity work today on the in-laws swimming pool . Seems the pump sprung a leak. I will keep in touch with Mitch for next weekend.

Foamguy

Hi Guys,

I'm trying to get caught up on all the PBF stuff. So much has changed with it over the last few months. As I said before, it evolved from a delta wing built much the same way. I was reading some back posts and Billy Hell was asking about a Speed 400 version. I dont have a clue about that, but I can tell you that my dad and I had some mini coro deltas with Norvel .074's on them that flew GREAT, so I suspect a small PBF made from 2mm coro would work fine for speed 400. LOL Ask RC_Eflyer to build one and try it, then I can see for myself. The 1/2A deltas were from 2mm coro, weighed about 22 oz if I recall. Not stellar performance, but good enough. Besides, they would do 360's in the width of our runway at about 6" altitude. On the other hand, they had the uncontrollable flatspin problem pretty bad.... stall one in a multiple loop and it comes down like a maple leaf, but never, ever did break more than a prop. Mine finally died when a flying buddy was chasing me down the runway with his Stick and sawed one of my elevons off with his prop.

Foamguy

rcman-RCU

My Feedback: (31)

Do the PBF's have the uncontrollable spin prolem both upright and inverted? It looks like the fin and rudder would be blanked out during an upright spin. The solution may be to extend a fin and rudder below the plane. What do you think?

Dave McDonald

My Feedback: (19)

rcman,
PBF spins aren't unrecoverable at all.....whether upright or inverted. But the spin recovery techniques are different than a normal plane. Go back to post #125 in this thread to read my post on Spin Recovery. In my browser, it's posted on page #7 of this thread.

Foamguy,
I hope your health is doing better! And I hope your family situation has begun to settle back to a more normal routine.

You NEED to try a MCP on your 40LA, 40FP, or 42GP on a PBF!!!! It made a world of difference in power, and actually reduced the overall weight compared to the stock muffler. My latest PBF with a TT 42GP and MCP is the most agile PBF yet. It has even surpassed the maneuverability of my Stickit in many respects, which I never would have dreamed possible. The other day, I was doing touch (bump?) and goes off of our windsock. It was fun!

Here's a photo of the latest PBF flying in Eldon, MO. Steve Sloan is holding his MDS 28 powered PBF, guided by a Futaba 8UAF.

Steven Sloan

The bump and go's against the wind sock are neat, but I still think you can do the landings on the tables like we talked about. I'll have to fill Dusty in on this.

Scorch

Steve, you are too kind. I'm still learning to fly the PBF. As you know I must keep it Dave-close, so I can see it. This is challenging for me. Don't get me wrong R/C Universe Readers, I'm not saying the PBF is hard to fly it's not. It's hard for me to fly it like I want because I have not flown a lot for a while. I'm getting better, but I'm not where I want to be.

I will be back Sunday to fly again can you join us?

I thought about a T-pin through an elevon and a tethered balloon. Hovering balloon bust?!

Foamguy

Dave,

Thanks for inquiring about my health and family situation. Yeah, looks like I'll make it Ya gotta get up pretty early to keep a good Foamguy down. As for my family stuff, about the same. It's amazing what a couple decent Dr.'s and attorneys can do really. So, having said that, I think Friday I'm gonna build my third PBF as I'm currently completely out of flyable planes and would rather spend 4 hours building a BF than repairing my old beaters or figuring out why my Saito has a stuck exhaust valve. Also, as I once told you before, I am indeed moving to Nebraska. Only the timetable has changed. Looks like about 5 or 6 months now. Nebraska just isnt all THAT far away from Lake Of The Ozarks as compared to Oregon

Hmmmmmm..... maybe this time I'll build a little one with Norvel .074 power for something new... seem to have plenty of 2mm coro laying about. Or maybe even a twin PBF. I built a twin powered mini Grim's Sickle with a pair of .074's once and it rocked ! So...... what was the final workable CG ya'll agree on for the PBF ? I just never quite got mine dialed in before I lost it. How large are your elevons ? Mine were pretty huge.... like funfly huge.....

Foamguy

Dave McDonald

My Feedback: (19)

Foamguy,
Glad to hear things are getting back to normal for you!

Once you get to Nebraska, we might even be within commuting distance.

I've been using 4" elevons on my PBFs, with 20" from the leading edge to the hingeline. They seem to work just fine, and I haven't even tried using extreme throws yet.

I've still been experimenting with the CG, and keep pushing it back farther and farther. I'm now flying my latest PBF at 6.0" back from the leading edge, which works out to be 25%. It's real close to neutral stability at 6" back, but I'm still going to keep pushing it back until I find it.

I test flew a guy's PBF today that was balanced over 7" back. It flew, but it was definitely too tail heavy. So at least I know that the rear CG limit is somewhere between 6" and 7 1/2".


Scorch,
If you'll bring the balloons.....I'll bring the T-pins!

Steven Sloan

Dusty, sounds good to me I,ll see you out at the field Sunday afternoon.