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View Full Version : Pitts Bipe ready for maiden


Grasshopper
02-17-2007, 04:47 PM
I think the only up side to having crappy weather for months on end is that I can get some planes put together so I'm ready for spring. Here's a few shots of my Richmodels Pitts Bipe. It's all done with the exception the battery hatch hinge. Fortunately I got to watch Hopper's Neighbor maiden his last weekend and it looks like a real sweet flyer. Admin and Mods, if this isn't in the right place, please feel free to move it. I wasn't sure which forum it should be in.

Wingspan: 32"
2908-10 outrunner
RCE 30 amp ESC
APC 9x4.5E prop
DN Power 3S 2150 15C Lipo
DX6 System
19.1 amps
205 watts
AUW: 31 ounces
105 watts per lb.

Balil
02-17-2007, 05:50 PM
me and the pitts dont get alot too well. but i hope she's a great bird for ya

gfdengine204
07-20-2009, 01:25 AM
I'm thinking I need to re-maiden this bird......I've only had it for 2 years.....LOL

Grasshopper
07-20-2009, 01:28 AM
That's plenty long Kev. It might not even remember how to fly now.

gfdengine204
07-20-2009, 01:32 AM
That's plenty long Kev. It might not even remember how to fly now.

As long as I remember, we'll be ok. :)

Grasshopper
07-20-2009, 01:33 AM
Do it!

groundrushesup
07-20-2009, 02:40 AM
As long as I remember, we'll be ok. :)

Speaking of...

I've never flown a Bipe before. What - if you had to pick one or two things - would be the major differences in control or feel?

Just a general question.

GRU

CHELLIE
07-20-2009, 02:46 AM
Speaking of...

I've never flown a Bipe before. What - if you had to pick one or two things - would be the major differences in control or feel?

Just a general question.

GRU

Bi planes have a lot of drag to them, keep the speed up, they are sometimes very touchy on the controls, because of the short wings, they bank/roll real fast, when landing, they just dont want to come down, have a lot of runway :D Take care and Have fun, Chellie



Shhhhhhh I had this bi Plane with a K&B 61, it flew great, was touchy, my brand new Comp. Airtronics radio took it out, No More Airtronic radios for me :D

http://www.greatplanes.com/airplanes/gpma0240.jpg

Grasshopper
07-20-2009, 02:49 AM
Chellie's right. This one does not like to land slow. The roll rates are not bad on it especially if you set up a dual rate with lower throws.

gfdengine204
07-20-2009, 03:01 AM
I've started experimenting with low rates on my elevator for landing, and it seems to tame down the airplanes and minimize the balloon effect I've been experiencing. I can imagine this would be a good plan for the Bipe too. In fact, I think this would be a good candidate for placing all my low rates on one switch.....

Rolling Thunder
07-20-2009, 03:03 AM
Lol,yep the one thing I found out the hard way is if you stall,you die.They lull you into a false sense of security with the way they fly so gracefully.You think they'll fly at a walking pace & then BAM,death spiral & its all over

CHELLIE
07-20-2009, 03:06 AM
A little and big Bi Plane :D

http://www.youtube.com/watch?v=cNqGPpgZ7x8



http://www.youtube.com/watch?v=FoB3gMCHvtk

CHELLIE
07-20-2009, 03:09 AM
I've started experimenting with low rates on my elevator for landing, and it seems to tame down the airplanes and minimize the balloon effect I've been experiencing. I can imagine this would be a good plan for the Bipe too. In fact, I think this would be a good candidate for placing all my low rates on one switch.....

Hi Kev :ws: Bi Planes, as do other planes, need a lot of down thrust to prevent the balloning affect, because of all the lift from 2 wings,or a big wing area, try that, Hope that helps, Chellie

Grasshopper
07-20-2009, 03:14 AM
Hey Kev,

If I remember right, that one did not have any ballooning effect. It did lul you in to thinking it would just float in to land and just like RT said, BAM! stall. As long as you keep a little speed on it to land, you'll be fine. Practice landing set ups well before your battery is nearing time to stop so you can get the feel of it and go around if needed.

gfdengine204
07-20-2009, 03:29 AM
Yeah I experienced the stall and die effect with the MiniPulseXT last weekend. Stall, then immediate nose-over and broke the motor mount. :( But I've been working hard this last week with landings, and think I am starting to get the idea. (Famous last words.....) But I am appreciating all the words of encouragement and advice.

Glad you started this thread Tom. :) Now come up here and fly it with me.

Grasshopper
07-20-2009, 03:32 AM
Yeah I experienced the stall and die effect with the MiniPulseXT last weekend. Stall, then immediate nose-over and broke the motor mount. :( But I've been working hard this last week with landings, and think I am starting to get the idea. (Famous last words.....) But I am appreciating all the words of encouragement and advice.

Glad you started this thread Tom. :) Now come up here and fly it with me.

Not to worry you, but I can assure you the stall and drop on the Mini Pulse XT is minor compared to the Pitts. If your Mini Pulse is anything like my Pulse XT 25e, it's a sweetheart to land compared to the Pitts. It would be easier for you to bring the Pitts down here and I would be more than happy to fly it again. :)

gfdengine204
07-20-2009, 03:38 AM
Easier for YOU, perhaps.....LOL

The MPXT stall was quite dramatic.....nosed up, then instantly dropped and nosed straight-in. Oh well.....I just wish it hadn't happened on that plane's first flight. :(

The wife is not too hip on me flying the Bipe, she really likes it as a hangar queen. Oh well, this ain't her hobby, now is it? ;)

Grasshopper
07-20-2009, 03:39 AM
Yep, you tell that woman just to keep supporting it financially and you'll worry about what to fly.

Let me know how that works out for you.

gfdengine204
07-20-2009, 03:44 AM
You are SO funny.....LOL

Rolling Thunder
07-20-2009, 04:00 AM
hey all,I just want to clarify.I have a foamy ultimate bype.I was just responding to Grus general question.
I always take all my planes up high & stall them purposely just to get a feel for how they handle.
Ive always been able to recover no problem.I thought with twice as many wings it would be twice as easy-not so
the plane just did a perfect corkscrew from a 150 feet up.I had absolutely no control.
post crash inspection showed all servos working

Rolling Thunder
07-20-2009, 05:35 AM
I saw this & it got my mouth watering :ws:Pitts Special Challenger 40 - 42.5" ARF Nitro Gas Powered Radio Remote Controlled BiPe Airplane (http://www.nitroplanes.com/pispch4042ar.html).My question though is why is it so heavy?A 40 inch span at 5lbs,really?
Is there any way to lighten it

Ive got a Heads up 3548-07 that I want to use but only 3 cell lipos

CHELLIE
07-20-2009, 08:20 AM
I saw this & it got my mouth watering :ws:Pitts Special Challenger 40 - 42.5" ARF Nitro Gas Powered Radio Remote Controlled BiPe Airplane (http://www.nitroplanes.com/pispch4042ar.html).My question though is why is it so heavy?A 40 inch span at 5lbs,really?
Is there any way to lighten it

Ive got a Heads up 3548-07 that I want to use but only 3 cell lipos

Hi RT :ws: Figure a 80" W/S at 5 lbs, remember you have 2 wings :D the 3548 motor will not be enough power for that bi plane, its only good for about 70 oz of thrust, 5 lbs is 80oz, not even a 1 to 1 power ratio, you will need to use a 4248-08 on 4 cells of about 4500 to 5000 mah, that will give you 106 oz of thrust, or 6.625Lbs of thrust with a 13x4 e prop, at about 720 WATTS, Thats about 144 Watts per Lb, that would be about the minimum in power to use for that bi Plane, Take care and have fun, Chellie




http://www.headsuprc.com/servlet/the-1434/4248-dsh-08-Outrunner-Brushless-Electric/Detail

wilmracer
07-20-2009, 05:34 PM
I know what you mean about being concerned about the weight. My scratch build pitts is my first Biplane and it scares me a bit to have a 57" span weigh in at over 6lbs. I just keep reminding myself that there are two wings there...

Good Luck! Make sure you post video of the re-maiden!

gfdengine204
07-21-2009, 03:21 AM
Here are Tom's numbers from post #1:

Wingspan: 32"
2908-10 outrunner
RCE 30 amp ESC
APC 9x4.5E prop
DN Power 3S 2150 15C Lipo
DX6 System
19.1 amps
205 watts
AUW: 31 ounces
105 watts per lb.

I just got this bird ready for the maiden, and using the same prop, I have the following numbers:

Using a Thunder Power 3S 2100mAh 15C, I had roughly 12.3V and 18.8 amps, for 231W. 119.225 W/lb. But, I am not a big Thunder Power fan (so shoot me :Q), so I tried a different battery pack.

Using a pack from the first Wattflyer Buyers Club, a non-labelled HobbyCity 3S 2200mAh 20C, I got these numbers:

12.45V at start
25.53 Peak amps
303.8 Peak Watts :eek:
156.8 W/lb.

I think I'll get off the ground. Hope I come down in the same number of pieces as I take off with. :rolleyes:

Grasshopper
07-21-2009, 04:27 AM
Hey Kev,

Are those numbers after the motor has run for 20 or 30 seconds or right off the top? I think that motor has a max amp rating of 25 so you may want to use some throttle management at first. It will definitely get off the ground.

gfdengine204
07-21-2009, 04:33 AM
Those are right outta the blocks. These are the TowerPro motor specs I found online:

2908-10T-4Delta | Weight 105g | Volts 10 | Idle Curr 1.4A | 2-3 LIPO | kV 1000 | Max Eff Curr 28A \ Max Loaded Curr 34A/60secs | Max Power 320W/60secs | Props 9*6/10*5 APC-E

I didn't run them long, but the numbers dropped back a little - those were the peak numbers from the WattsUp meter.

Grasshopper
07-21-2009, 04:34 AM
I say let her rip! Figuratively speaking of course. :)

gfdengine204
07-21-2009, 04:37 AM
Thanks Tom. I'll find a nice day and go. Might be a bit, weather is turning sucky on my next days off.....I'm just glad to have her off the freezer and getting prepped for flight.

Rolling Thunder
07-21-2009, 04:52 AM
Hi RT :ws: Figure a 80" W/S at 5 lbs, remember you have 2 wings :D the 3548 motor will not be enough power for that bi plane, its only good for about 70 oz of thrust, 5 lbs is 80oz, not even a 1 to 1 power ratio, you will need to use a 4248-08 on 4 cells of about 4500 to 5000 mah, that will give you 106 oz of thrust, or 6.625Lbs of thrust with a 13x4 e prop, at about 720 WATTS, Thats about 144 Watts per Lb, that would be about the minimum in power to use for that bi Plane, Take care and have fun, Chellie




http://www.headsuprc.com/servlet/the-1434/4248-dsh-08-Outrunner-Brushless-Electric/Detail

Chellie thanks for the numbers.that kind of power would take me to a whole new level of flying.wonder if I want to go there...yea baby:$

just one more question for you all then I'll get out of Grasshoppers thread & start my own if I decide to do this

what do you think of this motor TR 42-60C 500Kv Brushless Outrunner (http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6231&Product_Name=TR_42-60C_500Kv_Brushless_Outrunner)
with 2 3s2200 20c in series for power

I'd like to stick with 3 cell lipos because my charger can only charge 6 at a time,thanks RT :D

CHELLIE
07-21-2009, 05:19 AM
Chellie thanks for the numbers.that kind of power would take me to a whole new level of flying.wonder if I want to go there...yea baby:$

just one more question for you all then I'll get out of Grasshoppers thread & start my own if I decide to do this

what do you think of this motor TR 42-60C 500Kv Brushless Outrunner (http://www.hobbycity.com/hobbycity/store/uh_viewItem.asp?idProduct=6231&Product_Name=TR_42-60C_500Kv_Brushless_Outrunner)
with 2 3s2200 20c in series for power

I'd like to stick with 3 cell lipos because my charger can only charge 6 at a time,thanks RT :D

Hi RT :ws: your lipos are only a 44 amp battery Max, you will puff them,that motor needs a max of 50 amps, and its best to have a reserve of 20% so a 60 amp lipo min. also, that motor is only a 500kv motor, so yes, you will need a 6 cell lipo to get any power out of it, some 4000mah lipos would be best, Take care and have fun, Chellie

gfdengine204
07-22-2009, 02:40 AM
Well, if the weather cooperates, I am thinking of taking the Pitts to the club field for a maiden. They are forecasting a possibility of rain and T-storms, but it's only 40%. We'll see. Worst case, it waits for tomorrow night or the weekend.

Ran a different lipo on her with the WattsUp meter, came up with ~22 amps and 256w, for 132W/lb. Should be plenty to giddy-up and go. :D

Rolling Thunder
07-22-2009, 03:17 AM
Kev,why no video of your maiden flights?You're a mod.....you should be leading by example

gfdengine204
07-22-2009, 03:21 AM
Kev,why no video of your maiden flights?You're a mod.....you should be leading by example

A major factor is, I don't have a video camera. A secondary factor is, were I to HAVE a video camera, my wife would get motion sick from filming.....:)

zdsweet
07-22-2009, 06:12 AM
Beautiful

gfdengine204
07-22-2009, 09:39 PM
Well kids, I got the Maiden off without too much trouble. The Pitts takes off within approximately 25 feet. Got her to altitude and trimmed and seemed to do ok. Was using low rates (60% of high rates, and 30% expo on all 3 control inputs), but needed more elevator to keep from nosing over on takeoff. Switched elevator only to high. I think if I fly this plane again I will need high rates on the ailerons too. She just seems sluggish in that respect on low rates.

I had a HECK of a time telling orientation on her. THAT was no fun whatsoever. I had two spotters with me, and they also were having a devil of a time telling which way was which. Granted, I don't fly super close, but still, it would be nice to be able to tell which side is which. She flies a little faster than I would like to keep her closer. When I tried to bring her closer, even slowed down, I felt like I was getting behind the aircraft.

I got her landed in one piece. She sure does like to come in fast. Nosed over right after touchdown, but no ill-effect.

Not sure when (if) I will take this plane up again. I had a perfect, calm-winds day for the maiden. She's just too purty to drive into the Earth.

Grasshopper
07-22-2009, 09:49 PM
Congrats Kev. At least it's still in one piece. It gets easier the more you fly it. I told you it likes to come in hot huh? :)

gfdengine204
07-22-2009, 09:50 PM
Yes, you sure did.....she just gets hard to keep oriented.....

Did you prefer her on high or low rates?

Grasshopper
07-22-2009, 09:52 PM
Yes, you sure did.....she just gets hard to keep oriented.....

Did you prefer her on high or low rates?

I typically took off on low rates, flipped it to high rates to fly around and then back to low rates for landing. I think once you fly it enough, you can just leave it on high rates all the time.

gfdengine204
07-22-2009, 09:58 PM
OK thanks. I'll see if I can get the nerve to take her up again.

stevecooper
07-22-2009, 10:22 PM
Yes, you sure did.....she just gets hard to keep oriented.....

Did you prefer her on high or low rates?
I had to change the color of mySe5A as I could'in tell which way she was go'in half the time!!:red: in low light conditions it was a crap shoot at best::o but a white top & red nose with Catapiller yellow on the bottom I know where she's go'in:ws: (scale Bub's are appaled) had'in crashed her sence (100's of flights!:silly:)bubsteve:ws:

gfdengine204
07-22-2009, 10:37 PM
I am contemplating some Hi-Viz yellow tape to the underside.......