MarkShapiro

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This has been a long time coming, but finally got around to getting my 3W Bearcat on the table. I actually started the build about three months ago with the crazy idea of having her ready for the mid-October Giant Planes event in Lakes Wales, Florida. Unfortunately, while a ton of work has been completed, it does not look like she will be ready. The further bad news is that in trying to get her finished, alot of initial build steps were not photographed, so I will promise to take more shots going forward.

The 'Cat will be powered by a Moki 215 radial, has Sierra retracts for the mains and tail, Hitec's new powerhouse digitals on all surfaces and, of course, guided by the venerable JR 10X on 2.4.

Although the Bearcat is all composite with panel lines and rivits molded in, this kit can in no way be classified as an ARF. Lots of building to do and even more detail work to be done to get this baby to look the way it should. Also, there are no real building instructions or build photos included with the kit. All that is sent is a few absurdly crued hand drawings and a few sentences explaining them. Bottom line, this is a builder's kit and one must draw on all previous building experience to get it done. That said, I find the Bearcat to have a pretty scale profile and am impressed with the kit generally.

I started with the horizontal stab. Though not pictured, the elevators were balnced using lead shot at the leading edge. This was done to counteract the reported tail flutter from guys who have experience with the model. Elevators are perfectly balanced now, but alot of tail weight is the penalty. Nevertheless, I'd rather have tail wait to deal with than flutter. The pic below shows an internal mounting of the elevator servo. This differs from the designed method of pushrods exiting the fuselage from a servo in the fuse. I prefer a direct and short linkage by putting the servo in the stab. I expect this will also limit flutter possibilites. Finally, the servo pictured was inserted for sizing purposes only. So, don't anyone get upset!

For you guys who have been down this road, please feel free to chime in. That goes for the rest of you builders out there too.

MarkShapiro

My Feedback: (52)

As I saw it, there were two ways to mount the horizontal stab to the fuse. One way was to permantly glue the stab to the fuse, and the other way was to make them removable. I always prefer removable stuff, but have to be sure to use a system that would ensure that the stabs would not fail in flight.

As you can see, my solution was to build two "false ribs" at the front and center of the root rib. The good news is that the skin of the stab has a small lip extending over the factory installed root rib, which provided just enugh space to add my false ribs using a little more than quarter inch birch ply. I then put a blind nut on the inside (glue side) of the false ribs. Inside the fuse, I did the same thing and made hardwood doublers for 10-24 screws to be drilled through. As the photos show, the stab slides onto the aluminum tubes and is pulled/held in place tightly against the fuse by the screws pulling the stab in from the inside of the fuse. Not a unique idea, but I think very effective. One thing about this kit, the seems between the stabs and wings is flawless. Finally, the last pic shows the exit slot under the stab that the servo arm will come out of.

ZERO-322

My Feedback: (2)

POST more pic ! LOL sounds good so far , I like your solution to eliminate flutter I would love to see some pic of the linkage set up etc , looks great so far , I have a similar problem I was working on and I like that you have the servo hidden , many reasons to do it your way and few not to , you may have inspired me my friend ! by all means BUILD AWAY !

Mike

MarkShapiro

My Feedback: (52)

Thanks Mike. You are correct about the elevator servo set up. There are pros and cons to every system, it seems. I decided as I did for a few reasons, but mostly to combat flutter: Short and stiff linkages can be obtained this way versus a long pushrod, even if it is a carbon rod etc. I also think it is a cleaner look thatn having rods exiting from the fuselage sides. Only cons doing it the way I did is that there is an additional weight penalty and, I would have liked the control horn on the elevator to be a little further outboard than where it will end up. Not that big of a deal, though. Many more pics to come . . .

mick15

Hi Mark, I have built and flown one of these. Any help I can give just ask.

m

JohnVH

My Feedback: (38)

Subscribed, Mark this combo is my dream warbird setup -jealouse-

MarkShapiro

My Feedback: (52)

Thanks Mick. Yes. I read the thread depicting your Bearcat being painted. What a beautiful job. I see that you mounted the servo in the stab as I have. Has this set up presented any issues for you? Looks like you are holding your stab to the fuse via rubber bands. Very clever.


Thanks John. The combo should be great. We shall see.

mick15

I didn't feel the need to balance the control surfaces. I believe flutter is caused by poor linkages, with quality servos (JR8511) and tight linkages none of the surfaces flutter.

m

Erich

Hi Mark,

great plane. I have also some experience with the 3W Bearcat. Take your time for building. If you need any help just tell me.

Some pics from my Bearcat:

Greetings from Austria

Scott Prossen

Hey Mark,

I will be following the build with great anticipation. I've always liked the Bearcat and you know my heart is shaped like a Moki so what better combo could you have. Thanks for taking the time to produce a build thread. Should be fun. I look forward to seeing you at Monster Planes. It seems to be right around the corner. See you soon.

Kindest regards to you and the family,

Scott

MarkShapiro

My Feedback: (52)

Good top hear from you, Scott. Yes, I too am looking forward to Monster Planes. Again, too bad the Cat won't be ready, but you and I will enjoy flying our Trojans. A little formation this year will be great.

Hello Erich. Thanks for your offer of help. You will recall tht I purchased some of your very nice pre-fabbed building stuff for the Bearcat. I used most of it and used some of it in a modified manner.

Next, I turned to wing set up. Here too, although not pictured, the ailerons were balanced to take every precaution against flutter. I also decided to set up my linkages externally (a little more conventionally) rather than internally as designed. I felt that I had more mechanical advantage on the flaps and ailerons doing it this way. Again, pros and cons on both set ups. Eitehr way, I really had to clean up the factory pre-cut out servo covers. Looks they were cut out using an axe! However, nothing a little patience and alot of bondo couldn't fix.

You will also notice that I used the same system with the wings for holding them tightly against the fuselage as I did with the stabs.

You can also see the anti-rotation pins I installed at the leading and trailing edges of the panel. Probably not necessary given the hold down screws, but again, can't hurt. They are carbon tubes inserted into brass tubes. There are corresponding brass tubes that these slide into in the fuse.

MarkShapiro

My Feedback: (52)

I also wanted to cover or "cap" the ends of all the control surfaces. They come from the factory opened. Not much complexity here, but it will provide for a more finished look after painting.

Howard Davidson

Gotta love seeing you guys discuss this plane. I flew one of these for 7 years and had the time of my life showing it off and flying it. As was pointed out, it's NOT the best kit for anyone starting off in this hobby! I never had any flutter problems or anything else of major concern go wrong that I didn't cause myself. I sold the big "Cat to a guy named Dave Szabo in Minnesota about a year ago and now he's flying the darned thing and likes it. As much as I loved the plane I'd NEVER buy another 3W version as they're over-priced for what you have to do to make it into what it should be. It's not a matter of trying to save a few bucks on a Cadillac plane, you just don't get your money's worth as it comes from 3W. The end result for you guys with some stamina and patience will be a plane that'll knock your socks off. The Bearcat was the best flying warbird I ever flew and it presents very well for crowd (WOW!) appeal. Have fun guys.

Howard Davidson

One more pic that didn't load!!!

smurfjet

My Feedback: (40)

Hey Mark,

Good to see you getting on the Bearcat. I have always thought that my yellow aircraft Spitfire is one of the nicest flying warbirds I've owned (do you still have yours). The 3w Bearcat is right up there on top of the list now. This is Howard's old plane. I've flown it only a dozen times but it is one sweet flying plane. It's 49 pounds without fuel but honestly feels like it's a 25 pound bird on landing. There's so much wing area that you can land at a crawl.

Howard did a great job on the build. It's flying with an old 3w-120 engine that I had on the bench. I'm turning a 28-12 3w prop and it's a great combo. The radial will be an added "cool" factor for your plane.

The tail group was completed as yours is with removable stabs. The entire tail is nice and stout. No play at all in the tail. You can grab the vertical and it's solid when you move it back and forth. Cal Branton here in town lost one due to the tail basically shaking apart with flutter so just check that all is good there.

Howard sent me a small schematic in German that had the cg on it. I can't remember off hand but will get it for you. I confirmed this with Arnold Marcus who was flying one down in FL. I balanced it per this number and it's perfect.

Palmer Johnson took a few pics of the Bearcat at the Warbirds over the Midwest in FonDuLac WI. Thought I'd post them here.

Your build is looking great! Have you picked out a paint scheme for it yet?

Dave

MarkShapiro

My Feedback: (52)

Howard,
I have to agree with you on the "price vs. what you get" with the Bearcat kit. This is my first 3W kit, so I can not speak to their others, but as you point out, not much stuff in the kit for the price. that said, I love the surface detail and, again, the parts fits are dead on.

Dave,
You are very lucky to have picked up Howard's 'Cat already built and ready to go. Also, thanks so much for the tips. I did hear from another Bearcat owner about checking the stoutness on the verticle stab. Mine appears to be very solid, I am happy to say. Also, I would love the CG info. The CG is one of the very few bits of information that came with the kit, but I always feel better trusting the "as flown" experience of guys who are actually flying the model.

Also, I know Arnold Marcus. Great guy and a super member of our hobby. I think Marcus recently sold his Bearcat or is looking to sell. Looking forward to seeing him at Monster Planes down here in sunny Fla. Arnold always brings cool stuff.

Howard, where did you get your pilot?


More pics to come . . .

pitsspecial

Hi Mark,

Well its nice to see another one of these kits being built, a friend of mine has just bought one of these kits, hopes to fit a flat twin of around 120cc, im sure he will join in with the thread, i enjoyed painting Micks 3W Bearcat.

Not quite the same, but i have had the Ziroli Bearcat plans enlarged and am waiting for the laser cut parts to turn up so i can start building, just could not afford the composite kit!!

Happy building,
Di n Dave...

MarkShapiro

My Feedback: (52)

Hello Dave. I followed your thread on the paint job of Mick's Bearcat. Beautiful work. One of a kind. I am only too sorry to now recall (sorry Mick) that Mick's plane inexplicably went in only after a very short, yet impressive, life. That is heartbreaking. Ziroli's bearcat is very nice too. The enlarged version that you are planning will doubtlessly be very impressive. Can't wait to follow you rbuild thread on that one.

Howard Davidson

Mark,

I got the pilot and interior kit from Bobby Wilson at Cactus Aviation when I bought the 'Cat. It was like pulling teeth to get the stuff after paying for it and the interior kit was from Bobby's plane he dorked. Bobby swore he can't get either of these items any more after I bought him out but you still might try to prod him and see if the story is the same as 9 years ago! If I remember, the pilot was an old MGA pilot and I don't have a clue where the interior kit came from. I'm building a smaller 'Cat right now so I'll get to deal with this all over again myself!!!! I love the big 'Cats so much I just can't do without one any longer!!

p-51 flyr

My Feedback: (44)

Cool glad to see a build on this plane. I just bought one and plan on starting to build next week on my vacation.. Wish i had the moki 215 for mine , but will have to settle on a 3w 157 instead . Looking forward to watching and building along with you Mark

Tim

MarkShapiro

My Feedback: (52)

Thanks for the info, Howard. I will see if he has the pilots still. I got my cockpit kit from Dynamic Balsa. He has a custom made one for the 3W Bearcat. Pretty nice kit.

Here are a few more pics. These show the interior of the fuse where the wings get olted on fromt he inside.

Jetjockgb

My Feedback: (4)

Hi Mark,
Any more updates!!!! prety please!!!! I have one coming my this week. Got my scheme sorted!!

Cheers Graham B.
WWW.TIGERMODELS.NET

pitsspecial

Hi Guys,

Keep this thread going, im getting excited now!!!!!!!


Be good to see your Bearcat Graham, going to be good to have a couple of these, mine will look like my old Ziroli one, but a little bigger!!!



Di n Dave....

Jetjockgb

My Feedback: (4)

Hi Dave,

Yep should be good for next year and remember JC'S HOTBear!!! we will have our own reno!!!
Found some nice new bits!!!!

Cheers Graham B.
WWW.TIGERMODELS.NET

MarkShapiro

My Feedback: (52)

Alright gentlemen, the build continues: I am usign Sierra Retracts which are truly a work of art in cutting aluminum and steel. However they are not scale. As such, there is no way to attachthe strut cover so that it will completely cover the landing gear housing when retracted. In fact, about an inch and a half needed to be cut from the top of the strut cover to allow for the gear being deployed. It actually looks fine while the gear is deployed and "okay" while retracted. You all be the judge of its appearance. The full size Bearcat's gear actually articulated to the "center" of the gear houseing, thus allowing the strut cover to completely cover the housing when gear retracted. Oh well, a small inconvenience.