HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Jul 29, 2012, 11:17 PM
Registered User
Bountiful, Utah
Joined Dec 2003
97 Posts
OK, The Big Bird XL is 99% finished. Here are a bunch of shots and most of them are very redundant, but I am so happy the way it turned out that I just has a hard time stopping the camera shutter. The covering colors and scheme are the same as my earlier post about 4 years ago when I finished my 100" Big Bird.

The finished nose on this turned out even better than I had hoped. I used a 2 part epoxy paint (Klass Kote) that goes on easy and is quite forgiving for an amateur painter like me. I used a cheap automotive touch up gun from Harbor Freight. The paint is similar (almost identical to the old K&B Super Poxy).

As you can see in some of the photos the fuse is painted from the nose to about 2 inches behind the trailing edge. The Spinner is a turbo spinner from Esprit Models and is made in Germany. This spinner allows air flow into the motor area and eliminates the need for an air scoop. But for only 30 second motor runs, cooling is not critical. Motor runs are just long enough to get to altitude, then is is gliding and soaring until you land land. The spinner is 50mm in diameter.

I covered the sailplane with UltraCote Lite in transparent yellow and purple. All up weight is 51 Oz including a separate battery pack for the servos and Rx.

I use Dubro swivel links in the rudder and elevator to eliminate any binding and they work sweet.

The Big Bird balanced out perfect by just moving the 2200 3 cell LiPo forward or back in the fuse area under the wing.

I will report on how she flys in the future. Hope this thread has been a little helpful to some of you building the Big Bird XL electric version.

Dave
dwmumford is offline Find More Posts by dwmumford
Last edited by dwmumford; Aug 01, 2012 at 03:47 PM. Reason: ADD PHOTOS
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 30, 2012, 09:30 AM
Registered User
Chico, California USA
Joined Mar 2003
462 Posts
Dave,

Outstanding! Shape of the nose (foreward of LE) is the best I have seen. I expect it to fly as well as it looks.

Three questions: What kind of bucket is in the photo? Why did you not finish the entire fuse with paint? Is the XL fuse identical to the standard BB (length, width etc)?

Again, well done.

Wayne
Salmon-Run is offline Find More Posts by Salmon-Run
Reply With Quote
Old Jul 30, 2012, 01:34 PM
Registered User
Bountiful, Utah
Joined Dec 2003
97 Posts
Quote:
Originally Posted by Salmon-Run View Post
Dave,

Outstanding! Shape of the nose (foreward of LE) is the best I have seen. I expect it to fly as well as it looks.

Three questions: What kind of bucket is in the photo? Why did you not finish the entire fuse with paint? Is the XL fuse identical to the standard BB (length, width etc)?

Again, well done.

Wayne
The bucket is really a planter bucket ...sort of a brass color. My wife showed up with it one day.

Epoxy paint adds too much weight to the tail. The fuse was not painted aft of the TE of the wing to keep the weight down in the back so that no ballast is needed in the nose. Weight in the back takes 2 or 3 times the weight in the nose to compensate. That is why I use light carbon fiber push rods. I used the same method in my first BB (non electric) and did not have to add any ballast in the nose.

The fuse in the XL kit is the same as the regular BB kit. The mod on the plans show the same width fuse in the nose as the fuse width under the wing. I had to purchase some light ply for the bottom of the fuse because the light ply supplied in the kit is tapered at the nose. You have to allow more width in the nose for most outrunner motors. Otherwise the fuse is exactly the same in every respect including the tail feathers.
dwmumford is offline Find More Posts by dwmumford
Last edited by dwmumford; Aug 21, 2012 at 04:36 PM.
Reply With Quote
Old Aug 02, 2012, 05:00 PM
Registered User
doc993's Avatar
United States, WI, Stoddard
Joined Dec 2009
1,106 Posts
Great job! the nose mod's came out perfect, and the color's as well.There was a plane at the Nats last year with similar colors and it was easy to see compared to the other planes.( Kick Ace video). Good luck.
doc993 is offline Find More Posts by doc993
Reply With Quote
Old Aug 03, 2012, 06:29 PM
Registered User
Bountiful, Utah
Joined Dec 2003
97 Posts
REPORT ON MAIDEN FLIGHT: Well the batteries were all charged and I balanced the Big Bird per Ray Hayes instructions where he recommends the CG be set. Then I took the Big Bird out for just a hand launch from a little hill on a grassy field. I tossed it straight ahead and it gently climbed 2 or 3 feet then nosed down just a little and floated about 100 yards to a perfect landing. Then one more toss just to make sure. She floated nicely and eventually settled to the grass about 200 feet out.

Then I headed out to a flying field in the wide open spaces. Only one other person was at the field and when he finished flying I told him this was a MAIDEN FLIGHT, so he just watched. Well this time I powered up the electric motor and tossed the Big Bird XL into a 3-4 mph gentle breeze. She went up at about a 35 degree angle with almost no trim needed. At 200 meters, the altitude limiting device (from Soaringcircuits.com) shut off the motor, and then I was on my own gliding on wings alone and hunting for thermals. The Big Bird settled down with a nice a flat glide with just a tad up trim on the elevator and was off looking for thermals. I'd say I lost about 150 feet before I found indication of a little lift. It wasn't much, so I took off in a westerly direction. Before long my right wing tip raised up, so I gave her right rudder and kept circling. As she drifted downwind I just kept circling and she just kept going up as I circled like a homesick angel. What a rush!

Well, to make a long strory short that was repeated several times and finally I used spoilers and brought her down. At about 150 feet I retracted the spoilers and set up my final for landing, then at about 50 feet, I deployed full spoilers again and she sank at a predictable rate...then a little up elevator just before touch down and she skidded in for a perfect landing. WOW! I was excited. It was a 33 minute flight after the motor turned off...and this was only its first powered flight.

Now a few other comments COMPARING this BB XL 110 inch electric version at 52.8 oz weight, with my stock BB with 100 inch wing, AT 40 oz and no power: The handling of the BB XL is not quite as nimble as my 100 inch Big Bird, but that would be expected because it is 12 oz heavier and has 10 more inches of wing. Still, it is plenty responsive and also flys a little faster due to the 12.8 oz of extra weight. It will turn tight flat circles in a thermal if needed.

I can now give a strong recommendation for this kit. It is of very high quality and a joy to build. It flys wonderfully and really takes advantage of the thermals. I COULD NOT BE MORE PLEASED. I would use the CG location that Ray HAYES RECOMMENDS. Maybe start out with the CG 1/2 inch forward of his recommendation and then work back. But since I already had a Big Bird and was familiar with how it flew, I just set the CG at the recommended location and it seemed just about right. The BB indicates lift very well and really has a flat glide. I love the looks of this sailplane. If you like RES and like to build, I would highly recommend this plane. It is so nice to go out to the field and not worry about setting up a winch or hoping someone else is there with one. You just power up and fly. This sailplane is a nice size to transport with the removable wing panels. I hope to get many more flights over 30 minutes. Oh, it looks like I will get about 5 launches with a 2200mA 3 cell LiPo battery, with my setup.

I ran the motor on the bench and with my setup using a 30 second motor run and I did not get enough heat buildup (in fact the engine was just barely warm to the touch) to bother with making holes in the fuse for more ventilation. Remember now, I use the altitude limiting device that will shut the motor off at 200 meters elevation, or a 30 second motor run time, which ever comes first. However, if you like to fly around with the motor on a lot, you may want to make some holes in the bottom of the fuse for better ventilation. But I prefer to leave the holes out unless you really need them. Experimentation with your motor, prop and battery set up will tell you if you need ventilation holes in your fuse. So I would wait until the very last...after you have test run your motor on the bench, with hatches and canopy installed, to see if you need additional ventilation. Check the temperature of your motor and battery to see how hot/warm they are. Best of Luck.

Dave Mumford

Dave
dwmumford is offline Find More Posts by dwmumford
Last edited by dwmumford; Aug 03, 2012 at 06:50 PM.
Reply With Quote
Old Aug 03, 2012, 08:52 PM
Gasbags & Gussets
jswain's Avatar
Riverside, Ca
Joined Feb 2009
1,179 Posts
great news

i am glad it worked out so well for you and the model.

the first fight of a homebuilt model is usually my highlight of the whole modeling experience and makes me the proudest.

Thank you also for the tips and hints, especially the BB std vs. BB-xl(what i have) .


js
jswain is online now Find More Posts by jswain
Reply With Quote
Old Aug 04, 2012, 09:13 AM
Registered User
Hawksnest's Avatar
United States, PA, Perry
Joined Apr 2002
488 Posts
I've been flying BBs and modified BBs since 1998. I have 11 of them in various combinations. As for wing span, I fly the 100", a prototype 112", later settled at 110" in the kit, and one with a 120" wing. All are on the same fuse and tail, and all turn and fly great. I also fly about 6 pod & boom custom fuses I call the Virga. I made the mold for the pods, use a Bubble Dancer carbon boom, and a flying stab with Bud Elder's mount. I fly the same wings on both type fuses. I also have built 4 and still fly 2 Skybirds at 132" span.
I have some with flaps and some with spoilers on the wing. In the past two years, I have converted three Big Birds, one 2m Lil Bird, and one Skybird to electric power for ALES contests. My Big Birds climb the 200 meters in about 18-20 seconds. They will climb vertical but that's not the smart way to climb for ALES, better to go further in search of lift. In stead of tearing the nose apart to mount the motors, I put them on front where I cut the nose block off. Ray will soon put my method on his website. I can't see much difference in drag in thermal flight with the motor hanging out front. I placed 6th out of 50 flyers at the biggest 2-day ALES contest ever held, the 2012 Polecat-Soaring Circuits in Carlisle, PA.
Bill G.
Hawksnest is offline Find More Posts by Hawksnest
Last edited by Hawksnest; Aug 04, 2012 at 10:24 AM.
Reply With Quote
Old Aug 04, 2012, 03:27 PM
Registered User
Bountiful, Utah
Joined Dec 2003
97 Posts
Quote:
Originally Posted by Hawksnest View Post
I've been flying BBs and modified BBs since 1998. I have 11 of them in various combinations. As for wing span, I fly the 100", a prototype 112", later settled at 110" in the kit, and one with a 120" wing. All are on the same fuse and tail, and all turn and fly great. I also fly about 6 pod & boom custom fuses I call the Virga. I made the mold for the pods, use a Bubble Dancer carbon boom, and a flying stab with Bud Elder's mount. I fly the same wings on both type fuses. I also have built 4 and still fly 2 Skybirds at 132" span.
I have some with flaps and some with spoilers on the wing. In the past two years, I have converted three Big Birds, one 2m Lil Bird, and one Skybird to electric power for ALES contests. My Big Birds climb the 200 meters in about 18-20 seconds. They will climb vertical but that's not the smart way to climb for ALES, better to go further in search of lift. In stead of tearing the nose apart to mount the motors, I put them on front where I cut the nose block off. Ray will soon put my method on his website. I can't see much difference in drag in thermal flight with the motor hanging out front. I placed 6th out of 50 flyers at the biggest 2-day ALES contest ever held, the 2012 Polecat-Soaring Circuits in Carlisle, PA.
Bill G.
Good to hear from you Bill. Its been a few years since we last communicated with each other about our BB's. Flew today with my new electric BB and caught some big thermals and specked out. Really a lot of fun. I would be interested to know the motor and prop combination you use on your Big Birds. I use a modest motor...the Turnigy 3536-1100 with 11-6 or 12-5 folding prop from Aeronaut. I am using the Soaring Circuits CAM for ALES competition. It works nicely. I am still going to experiment with prop and motor combinations. The one I use now works OK, but I would like a little more power.

Dave
dwmumford is offline Find More Posts by dwmumford
Reply With Quote
Old Aug 04, 2012, 05:57 PM
Registered User
tomcat5109's Avatar
USA, TX, Houston
Joined Mar 2004
288 Posts
Hi Bill. I was at this year's Ploecat/Soaring Circuits contest. I wish I paid more attention and got some close looks at the BB as I'm contemplating building one. Would like to see your custom fuselage version.
tomcat5109 is online now Find More Posts by tomcat5109
Reply With Quote
Old Aug 04, 2012, 06:30 PM
Registered User
Hawksnest's Avatar
United States, PA, Perry
Joined Apr 2002
488 Posts
I don't have the mold for the Virga pod anymore, I gave it to a friend of mine, Ken Bates from MI, after he put his Virga plane in at the nats. I will take a picture of it later.
Dave, good to hear from you. My power system after trying a bunch of combos
Tower Hobbies Rimfire 15 outrunner, 11 X 8 Aeronaught folder, Castle ICE lite 50 amp esc, and on 4 cells-- Thunder Power 65C 4 cell batt. With spoilers at the contest, I got 5 climbs/flights, then grabbed another plane for the 6th. When I got home, I did another climb to altitude on the first plane, and it worked, but I didn't want to push it. The battery is velcrowed under the wing rod to balance. When I fly flaps, I don't turn them on while climbing or thermalling, I only use them when starting down to land. Bill G.
Hawksnest is offline Find More Posts by Hawksnest
Reply With Quote
Old Aug 05, 2012, 03:58 AM
Registered User
United States, IN, Fort Wayne
Joined Apr 2003
1,571 Posts
Bill,

" My power system after trying a bunch of combos
Tower Hobbies Rimfire 15 outrunner, 11 X 8 Aeronaught folder, Castle ICE lite 50 amp esc, and on 4 cells-- Thunder Power 65C 4 cell battery. "

Thanks for posting your power set up, I'll include it on my web to help others deciding on what equipment to use. What battery charger would you recommend ?

Ray
Sky Bench ... Woodys Forever
WWW.Skybench.com
Ray Hayes is offline Find More Posts by Ray Hayes
Reply With Quote
Old Aug 05, 2012, 08:18 AM
Registered User
Hawksnest's Avatar
United States, PA, Perry
Joined Apr 2002
488 Posts
I use an E-flite programable LiPo charger, and the FMA Cell-Pro 4 is also a good one. I use a garden tractor size sealed gel cell battery for charging, both shop and field. There are many good chargers on the market, both AC & DC. Bill
Hawksnest is offline Find More Posts by Hawksnest
Reply With Quote
Old Jun 27, 2014, 08:15 PM
Registered User
United States, MO, St Charles
Joined Nov 2013
3 Posts
New Big Bird XL in the Neighborhood

I finished my Big Bird XL and had a chance to fly it - WOW ! This is the 110" version and since I used the motor for launch was able to keep the weight down. Cover is UltraCoat Trasnparent Yellow and UltraCoat ParkLite Flame Red. AUW came in at 38.25 oz. The only modification from the original design is the incorporation of two plastic 6-32 screws that secure the wing panels to the fuselage (no tape for me)

I used a Keda 22-22L motor, 1000mah 3s LiPo, and a 30amp ESC from Strong Motors. The 11 x 6 prop provides awesome launches. I think you could get 4 or 5 launches from a charge. This set-up yields a 45 degree climb.

The flying characteristics are very pleasing. Easy to see lift even for a newbie like me, the glide angle is very flat in zero lift and slows down to a nice controllable speed for the approach to landing. I like the spoilers ability to kill some of the lift without a pitch change on landing ( I did mix in some down elevator upon deploying the spoiler). Several of my landings were right next to me.

Many thanks to Don Armstrong at Strong Motors for the fine inventory of power products and endless patience with me on questions, and a Big thanks to the Big Bird extraordinaire, Mr. Ray Hayes at Sky Bench.
Frisbie is offline Find More Posts by Frisbie
Reply With Quote
Old Jun 27, 2014, 08:52 PM
Registered User
United States, MO, St Charles
Joined Nov 2013
3 Posts
Maiden Flight of Big Bird XL

Here is a link to my FaceBook video of the maiden flight of my BBXL. After I launched a couple times I felt comfortable at 40-45 degree climbs. My best time on day one was 31 minutes - we have been having rain every day for a week. I can't wait to fly a day with some lift!

https://www.facebook.com/photo.php?v...84818763779190
Frisbie is offline Find More Posts by Frisbie
Reply With Quote
Old Jun 28, 2014, 07:58 PM
Registered User
United States, IN, Fort Wayne
Joined Apr 2003
1,571 Posts
Ladies and Gentlemen, we have a prof. builder in the house ...

Congrats John.

Ray Woodys Forever
Skybench.com
Ray Hayes is offline Find More Posts by Ray Hayes
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Electrify Ray Hayes 100' Big Bird?? dwmumford Electric Sailplanes 11 Jul 30, 2012 05:04 PM
Discussion Electric Big Bird XL animalsmom Electric Sailplanes 3 Mar 07, 2012 10:38 PM
Wanted Big Bird nose cone Swoopdown Aircraft - Sailplanes (FS/W) 4 Feb 28, 2012 12:40 AM
Discussion How much downthrust on Skybench Big Bird XL electric? dwmumford Electric Sailplanes 4 Feb 19, 2012 03:06 PM