Bob757FL

My Feedback: (15)

Oh my gosh Reg, I can't believe you did these tips yourself! I think Bruce's website says that the prefinished ones he does will save you about a day of sanding. After taking one look at the finished product, I figured it would save me 1 week of sanding. When they arrived, I knew right away that these were done well beyond my abilities right now. He uses a spindle sander I believe. Whatever that is, I don't have one or even know where to buy one. you did great on your own though.

Wheelpants on an ugly stick? Its supposed to be UGLY! I'll send you a picture of my ugliest of sticks. It consisted of a GP 60 size fuse and tail with a set of Dave Patrick Extra 330 wings that were permanently glued together with an aluminum joiner rod after the thing crashed. The wings are obviously way out of proportion but they were just too pretty and undamaged to throw away. It flew OK and got lots of laughs. If you can, send or post a pic of your 215 stick as it stands today. Thanks for the update!
Bob

regmason

My Feedback: (2)

Bob,

Just a quick update. I have been installing radio gear in the SFK. I used 48" x 4-40 metal pushrods inside of .156 carbon fiber outer rods for the elevators. [&o]Bruce is concerned that the set up may reduce my effective radio range since I have run the antennas alongside the rods in the rear of the fuselage. Do you or anyone else have some opinions on the subject? I am using a dual receiver/battery setup for safety. I must resolve my current dilemma before moving on to covering.

Reg

Bob757FL

My Feedback: (15)

Reg, Your setup looks very similar to what we did with our single SFK. The only differences are that the the elevator outer tubes were fastened on every 1/2" balsa side stick that it crossed to absolutely insure against buckling and the inner control rod was the plastic one with metal ends screwed in. The reciever antennas were routed along guide tubes, one each side right next to it. I will try to email or post you a picture here so you can see how it was. There were no radio range problems. You might want to setup a reciever and do a range check before covering just to make sure the metal pushrods don´t present a problem. Walk down to the end of your street and see how it performs with a few servos.
Bob

regmason

My Feedback: (2)

Bob,

Just a quick note to let you know that I am still at it. My deadline of July 31st has turned out to be my biggest embarassment. My new deadline is "it will be done when it is done"! Maybe I won't miss this one. Below are a couple of pics showing my status. Fowler flaps are not installed and outer wing panels are missing. It should be flying by October.

Reg

mstroh3961

My Feedback: (4)

Looking good Reg! now get er done!

Bob757FL

My Feedback: (15)

Hi Reg,
Thanks for the update once again! It is looking better with every update. October? I don't know, 2 engines to get mounted and hooked up plus flaps, windows, control setup, and balance. That might be pushing it. December sounds more realistic if your weather is acceptable. Even the foamies take me 2 weeks anymore even though they are always advertised at an evening or two! Keep up the good work and keep the updates coming!
Bob

regmason

My Feedback: (2)

Bob,

Engines only require 4 bolts. Throttle servos and linkages are in place, as is all of the fuel plumbing. The flaps only need to be covered. Flap servos are already installed. All the radio gear: two receivers, elevator and rudder servos and pushrods are in place. I still need to cover the custom round cowls. With all that said, you are probably right. December it is.

Reg

Two weeks for a foamie. I am impressed!


By the way, the two pics I posted were number 662 and 663. This build is well documented.

Staudruck

Hello everybody,

My name is Frank and I´m new in this forum. We are interested to build a Twin-SFK for our research activities on autopilot development (university research project).
How long would you expect will it take to build a SFK for an experienced RC-model builder that is dedicated 100% to the SFK? My idea is to hire someone especially for that job.
Does someone yet know the level of vibration induced by two G38 (or similar) and how to reduce them? Are there fuel-motors that produce less vibration?

Thank you very much

Frank ("Staudruck" means dynamic pressure in german)

regmason

My Feedback: (2)

Staudruck,

I can let you know about the two G38s in about two weeks time. As for the build time, pay no attention to the time it took me. I am the world's slowest builder and while building the SFK, I built a couple of other airplanes. A 100% dedicated builder should take no more than a couple of months to complete an SFK. It should be a great platform for research.

Bob, Mike and the others,

I am down to covering the cowls and installing the window panes. I got sidetracked by a 30% Carden CAP 232 with a 3W75 that I bought off RCU. I will post a picture as soon as the King is in the A-frame being balanced.

Reg

Staudruck

Fobus,

thanks for the reply...

I printed the foto you posted, where the SFK is shown completely on a Ping-Pong table, and pinned it on the wall of my office to prepare me for whats comeing on. The dimensions of the SFK are really impessing!!!

I need to know some more details about the SFK:
- what do you (or anybody else who built a SFK) expect to be the max. Payload of the SFK?
- how much fuel does the SFK consume in normal flight?
- how much nose weight do yo need to trim the twin-SFK?
- what do you do to avoid RF-interference problems on the long servo leads that go to the aileron servos?
- are both motors RPM-syncronized or do you control them independently?
- would you recommend Zenoah motors for a flight mission of about 1 hour (or even more)? Are they reliable enough?
- does the magneto system of the Zenoah´s generate any interference trouble?
- are there any fuel-motors that support an electric generator to produce enough energy for the board systems?

As I told you in my first post, we are planning to use the SFK in order to have a research platform for autopilot optimization. The idea is to have an airplane that is capable of lifting a lot of payload (infrared-camara, data transmission, autopilot, batteries ...) and a lot of fuel to stay airborne for a couple of hours. The motivation of the project is to develop an own autopilot system for UAV flight-control for civil applications. We are collaborating with a local aircraft company (that builds real aircraft), so our new aircraft will be certified for autonomous operation. We need the SFK as a technology demonstrator, to get people interested in what we are developing.
I think we will start our project before end of the year and I would be glad to receive hints and tips from the experts that have yet built a SFK. Of course I will maintain you informed about our activities and advances, once we´ve started to build our first SFK (I think we´ll make several).

Thanks a lot. I love this thread, so I will stay tuned.

Frank

BruceTharpe

My Feedback: (1)

Frank, I've been out of town for a couple days, so I haven't seen your questions until now. I invite you to write an email to me at [email protected] so we can discuss your project off line.

Concerning your first question about payload, my guess is it that it wouldn't even breathe hard with ten pounds of payload. Twenty pounds should be very manageable with careful piloting. More than that and I'd consider some beefing up in certain areas. The fuselage is a huge box and it could probably haul your equipment internally.

As long as I'm here, I should mention that SFK kits are currently out of stock. A new batch is in the works and should be ready to ship by the end of October.

RCSHOWCASE

Finally!

Sunday Oct 02, 2005: First flight of my (David Garrison's) twin Super Flying King! Long time in coming but well worth the wait. She flew perfectly...take off roll at 1/3 throttle was about 100 feet (no flaps).

Andy Kane was the test pilot and managed to do : loops, spins, knife edge passes, one half a rolling circle, tried a torque roll but only managed to hang her on the props for awhile; (any one know if it is possible to troque roll a twin?) The SFK twin flies like a (big) ***** cat but is capable of doing alot more! See pics below. Andy also flew it in formation with an airliner coming in for a landing at Dulles International.

Those twin large gas engines sounded WONDERFUL!

The DCRC club members voted the SFK Twin "a KEEPER!"

Specs of SFK twin as built:

41.5 pounds (1.5 pounds lead weigh in nose to balance at CG)
2 ea ZDZ 40 RV gas engines , with 16 ounce tanks
Radio System used is the Multiplex Royal EV0 12


David Garrison
RC Showcase

Big is good, but Bigger is Better!

Skycam41

WOW!! Absolutely fantastic.....do you have any video footage? I bet Bruce Tharpe is tickled pink to see a twin of his SFK

regmason

My Feedback: (2)

Dave,

Congratulations! I hereby concede the honor of the first SFK twin flight to you. I have three more window panes to install and a balance job to complete before I am ready. My plan was to fly this week, but it looks like rain. I would love to see some video.

Reg Mason

Bob757FL

My Feedback: (15)

Congratulations Dave! It is beautiful. It must sound incredible too. I would pay money to see Andy Kane put it through the routine you described. The A330 "formation" shot was great timing! Thanks for sharing your pictures and project here. As Reg said, this should make your SFK Twin serial number 1 from the factory. If he gets the windows in and flies soon, he will have serial number 2. This puts you guys in a VERY select group of RC pilots/owners. Does anyone know how many SFK singles there are completed or at least a ballpark? Just curious.
Bob LeBlanc

BruceTharpe

My Feedback: (1)

Yes, I am absolutely thrilled! Congratulations David, it's a beautiful model and I bet it's quite a sight (and sound) in the air. Hope it serves you well as a flying billboard for RC Showcase. ZDZ's for everybody!

One thing I am curious about is pitch response with throttle changes. Did you or Andy notice any pitching due to the high thrust line? What size props did you use?

Again, congrats. You've got a unique machine there. Reg, you're next

Bruce

RCSHOWCASE

Bruce Tharpe wrote:

"One thing I am curious about is pitch response with throttle changes. Did you or Andy notice any pitching due to the high thrust line? What size props did you use? "

Bruce:

It has Bambula 20 x 10 props, and I don't recall any pitch changes, but the first three flights were so exciting it is hard to remember much detail, other than the pain in my face from smiling so much !

Bruce, this is a wonderful kit and has my highest recommendation for those that like big and solid flying models.

David Garrison
www.rcshowcase.com

regmason

My Feedback: (2)

Bob and the gang,

Tim Moser and I set up the SFK in my driveway to test the engines. Everything was going well until the right engine started dying unexpectedly. The problem was traced to an air leak at the fuel filter. In the meantime, the left side of the plane stopped working. Tim assumed a battery lead had come loose. I feared the worst. Tonight my fears were realized. The left receiver is dead as a doornail. And I don't know why. My first thought was to blame Tim. While setting up the quick charger, he plugged the Hitec 335 charger lead in upside down. But this should not have caused the problem. The JR charge/ switch isolates the battery from the receiver when it is off and connected to a charger and likewise isolates a charger from the receiver when it is switched on. The only other thought is that the receiver, a JR 950S, cannot handle the voltage level of a freshly charged 5-cell 6 volt NiMH battery. I have been told by others and threads on RCU that this is not a problem. This was the first time that I have ever connected a 6 volt battery to a receiver without using a regulator. I have another 950S receiver, but it is in my new CAP 232. My dilemma is: do I cannibalize a working airplane and plug the 950S into the SFK and thereby take the chance of frying another $200 receiver? Please advise.[]

[&o]By the way, I started the engines using the 32:1 Honda oil mixed fuel that I was told to use in the RCS 215 radial. This was a big mistake! The black gunk that spewed from the mufflers turned the SFK sides and tail nearly black. Attempts to clean it off with Windex only spread it around. 409 grease fighting spray did not help. Alcohol got most of it off, but some required using WD40 first, then use alcohol to clean off the WD40. I am going back to my 80:1 Amsoil mix. It does not generate black gunk. It may have been a big mistake to cover the King in white Monokote, especially since the mufflers are mounted on a high wing and spray exhaust down the sides of the plane. I spent two hours cleaning the fuselage and wing center section. Now, all the seams on the covering show since the gunk now outlines where they are.

The plan was to fly the King on Friday, but until I get a better handle on why a brand new receiver died, that is now on hold.

Reg Mason

regmason

My Feedback: (2)

The King is finished! I replaced both 950S receivers with a couple of used 649S. I also added MPI 6 volt regulators. Since I don't know if an over voltage situation caused the 950 to die, I didn't want to take any chances. I opened the dead 950 case and smelled burnt components. Maybe they always smell that way.

The King weighed in at 46 pounds and balanced perfectly with no additional weight. I guess my G38s are heavier than David Garrison's ZDZ40s. Add the fact that my STOL tips and Fowler flap hardware contributes some more weight. If it doesn't fly today or Saturday, then it will have to have its maiden flight at our club's fun fly on Sunday.

Below are some pictures, but they don't really show how big this sucker is!

Bob757FL

My Feedback: (15)

YEA REG!!,
This has been a long road that finally culminated in a beautiful plane. Your cowls and flaps look great. You have to get a picture of yourself squating behind the plane for people to really appreciate the size. These aren't fiberglass beauties painted in the mold, this is hard yet rewarding work transforming a box of machine cut parts and sticks into a 46 pound flying machine. Im sure the sound of both of those engines running in unison will be one noone at your field has ever heard there before. I forgot, did you put in a bomb bay? If you did, put some light objects to drop, even on the maiden flight. You'll have lots of people watching and you might as well test all of the systems out. Do you have the 7 inch tires on it? I know you have the JR 10X so you'll be able to program the flaps to come down slowly with servo speed function. Makes for a much easier transition. The automatic elevator compensation with flaps function also works very well although I never did figure out how to match the elevator flap trim speed to the slowed down flaps speed. Its Friday night and there is no flight report here so I guess that means its Saturday or Sunday. Hopefully you can fly it tomorrow before there is too many people around it asking questions while you are trying to remember to do everything right with a new airplane! Give us a flight report and make sure you have a friend take some digital pics. Good luck this weekend and congratulations on completing this huge project and making it look so nice.

Sincerely,
Bob LeBlanc
p.s. check you PM

Skycam41

All the best for your maiden....lots of pictures and if possible VIDEO please Put some foam between your knees, we would not want to hear that over the sound of the twin engines!

regmason

My Feedback: (2)

The King took to the air today, October 15, 2005, at 1:30 PM, one month short of two years when I glued the first parts together. It was warm, 85 degrees with a SSW to SSE wind of 12 - 15 mph. The engines were tached to 6400 rpm. The King is a heavy plane at 46 pounds and didn't exactly leap into the air. It may still be a little tail heavy. The G38s are adequate, but I wish I had gone bigger, say at least G45. On the third flight, after some trimming, it was flying pretty good. With the STOL tips and those huge wings, it doesn't want to land. You can land it into the breeze at almost zero ground speed without it trying to pancake in. I learned to make long low approaches for landing. I tried the flaps high in the air and it was good that I did. The nose pitched up 45 degrees (or maybe it just seemed that way) on application. This may be due in part to being a little tail heavy, but some automatic elevator trim will be necessary. The engines have very little vibration and sound awesome. Video was shot, but has to be digitized. It will be posted on our club web site when available. I have included a pic of the proud papa with his new baby.

Reg

BruceTharpe

My Feedback: (1)

Hey Reg, Congrats!!! It must have been something to see it finally in the air after all this time in the shop.

Did you miss the page where it recommends mixing in down elevator with the flap? Now you know

Regarding the power, what props are you using? Did all 5000 bits of monokote stay in place?

Good luck at the fun fly on Sunday, we're all looking forward to more reports and the video!

Skycam41

Awesome Reg!! Congratulations on your maiden flight, your SFK looks great and having you in the picture really puts some scale to this big bird. Please pass on the link to your clubs web site when the video is posted.

Cheers

Mike

regmason

My Feedback: (2)

Skycam41,

Someday, I would love to come to Canada and fly from that big concrete runway you have.

Bruce,

The Fowler flaps are extremely effective. I have just reviewed the video and the plane was never out of control. On the second flight, I accidentally took off with full flaps. It caught me by surprise. As you reminded me, I did go back and read in the instructions about including elevator trim when using the flaps. The left engine was running about 200 rpm below the right and required some extra rudder trim to keep the plane from drifting to the left. Of course this is probably due to the torque of two engines. As you may have surmised, this is my first twin engine airplane. Also, every plane I have ever built and flown (except for my Agriduck) was overpowered by at least 50% and had unlimited vertical. Thanks for reminding me that the King is what we refer to here locally as a "big fat lazy pig". I can't wait to see David Garrison's video of his King doing knife edge passes and a rolling circle. Andy Kane is my new hero.

The props used were 18 x 10. After the engines break in a little more, I will try something different. I will send you a CD soon of all nearly 750 pictures of the build and flight. I have enjoyed building the King immensely and have learned some invaluable techniques in model building and innovation. I would recommend this experience to everyone. I want everyone to know much I appreciate the personal information and support that you provided. A Super Flying King may not be everyone's cup of tea, but a Bruce Tharp Engineering kit should be. Long live the King!

Reg Mason