...Good question [:-]

.......Moved all servo's to firewall, new tank location, with new 14 oz tank...eng mount drilled and tapped.. Sprung tailwheel assy obtained and offered up lighter ..looks good..

Mine is still in the box, down in California. I am working in Alaska so my Bear will at least a year before it gets to the assembling table [] But I'll live vicariously through all of you people and learn from your experiences.

Don

Well, I got into my Rare Bear box last night and discovered that the mechanical retracts I had were not going to work on this plane. Soooo, I went researching back through the thread and broke down and ordered a set of Robarts (550's) with a set of 663 Robostruts to go with. Then I said "Why not?" and ordered a scale retractable tail wheel as well. I ordered the whole kit with installation kit and restrictor valves, quick disconnects and 3.5" Sullivan wheels with the3 aluminum hubs. These are the phnumatic retracts and that is going to be a new experience for me as I have never done retracts before, let alone gas powered ones.

Did I do good?

Nice gear......whats the weight of the whole robart package you got there ...?

You know what? I have no idea! The consensus seemed to be that if you were going to use Robart struts, the 550 series were the way to go and the set I ordered are designed for the 7/16" Robostruts so I ordered those too. It just kinda snoballed from there. Since I am using an OS 1.60 for power I'm sure it will fly well but the wing loading may be kinda high. Kike I said I am new to the whole retract idea so I am kinda clueless when it comes to the details.

Nice looking quallity gear though......that stuff is so expensive in this county though ....and not that readilly available..[]....i've managed to get some O.K Supra mechanicals though so all is not lost...

Lord Lucan, Are you installing the OS .91FX"C"?

Lord Lucan. they aren't exactly cheap in this country either. With the wheels and all I will have about $300.00 invested in them by the time they are on the plane. The mechanicals I have are made by B&D indrustries and they actuate from the wrong side. I guess they are designed for wheels that fold up away from the fuse, not in towards it. I had said I wouldn't invest that much money in this plane but after looking it over real well........... like I said I got carried away I guess.

The ones you have look good, they should serve you well. I would caution you to make sure the wires are good and stiff though if you fly off of a grass runway. One of the gents who flies at my club has a Hanger 9 P-51 and it winds up on its nose as often as not during landings because of the spindly gear wires (and his classy landings!).

..For sure.....with a great Slimline 'Pitts' muffler to suit.. here's the latest ..

another one ready for the races...just need to put some gas thogh the lead

Scale Man, Congratulations it looks great. Good luck in your maiden. Which engine end retracts did you select and what was your weight?

SC120 four stroke.......eurokit retracts (air)......10.5lbs dry.......no moving of servos...used the same tailwheel etc....
flying off grass...so it will be interesting!
just waiting for the weather now......not so good at the moment in the uk!! as usual

cheers

dave

Well, as soon as I hit the send button its off to the building room to actually get started on this monster! I had a conversation with someone at Thunder Tiger Friday and we were discussing the horizontal stabilizer failures that have been reported. He informed me that they were most likely due to "overpowering". I said "You mean something like an OS 1.60"? "Exactly" was his response. I told him that was my intended powerplant and he said the plane will take it but the fuse should have some lite ply added to the inside of the fuse where the Stabs attach. He said the fiberglass in that area was fine for the recommended engine but not strong enough for the stress imparted but a "grossly oversized" (his words) engine. Re-enforce it with some ply and it should be fine was his suggestion so thats what I will do.

Anyways, here we go off to the building room, the building room, the building room. Here we go off to the buiding room...... So early in the evening!

Overpowered?

Is the real Bear a stock Bearcat?

What did they think people would do with this plane?

DT

DT,

Good Point. I'm sure no one on this thread has every thought about "overpowering" their aircraft.....

BTW...talked with Jim today...said your bear is lookin' good!!!

Can't wait for the next fly in. Team Dago may have a couple entries of their own....

Can you post some current pics?

....Trouble here is this adds more weight just where you dont want it.. needing even more weight up front to balance the darn thing... ...all the time here the weights going up ....the wing loadings going up... its like Catch 22....

just build it.....and fly it......that's exactly what i'am doing......why over stress the airframe for a few more m.p.h. were not at the UK pylon races!!....

if you want speed build a jet turbine.....

dave

...Totaly spot on ......couldnt agree more.

I got the forward interior wood assembled last night and the firewall glued up. I used 3/4 oz. cloth on the points where the wood structure joins with the fiberglass fuse. All of the parts fit very well and the lazer cutting was nicely done. This is definitely not a good kit for a beginner though. The instructions for the front assembly are very incomplete and the pictures don't tell the tale as well as they should. If you are just starting this plane you should seperate all of the wood pieces and group them together. (servo tray, tail section, tail wheel assembly, firewall, etc.) Labeling them wouldn't hurt either. Then look at ALL of the pictures in the manual, several times, to determine the parts that are needed in each assembly. I fitted the parts together in the fuse and tacked them in place before hard glueing anything in place. Failing to do this may cause you to wind up with some pieces that don't go together without "modifying them". When I was done everything fit as it should and only minor sanding was required to fit the interior structure into the keyed slots in the firewall. When it is all together properly it is very sturdy and should not move. One change from the instructions, I would suggest not glueing the large fuse former into place (one of the first things the book tells you to do) until you have the servo tray/side structure in place. If you glue it in as directed, the large assembly will be difficult to fit, as it all fits together very well once in place.

I didn't start the tail/landing gear assembly last night because I feel I need to wait on my tail wheel retract to make sure all of that is going to go together as it should. I don't want to put it all in there and then have to rip it out again to modify it for the retract setup.

DT you are correct, they must have expected (and may be right) most people to build the plane as a Sunday flyer to look like the real thing and fly well. I am building it to look good and go like #e!! so I need to re-enforce it accordingly. Tonight I will tackle the wing mods for the landing gear that Vampire showed us a few pages back, but I am going to try and do it without cutting the wing skins.

My retracts and struts should be in tomorrow and then things will really start to roll! I will say this though, I like the way they set up the tail controls. When done, there isn't going to be much showing and everything should be good and stiff, with no slop to cause flutter.

I have been away from this thread for a bit and upon returning I have noticed the TT response linking the 1.60 to horizontal tail failures. This of course is quite possible due to the increased speed and thus load on these surfaces. However, the failures have occurred on airframes that WHERE NOT powered by this specific or other such size engines.

I have several flights on mine w/ the 1.60 without issues and WITHOUT any additional stiffening of the fuselage in the tail area or any mods of the stab itself.

I design and manufacture JET airframes and the RB, in my opinion, in its supplied form will take the 1.60 and other engines of similar nature but will be increasingly intolerant of improper flight control surface installations that MAY lead to FLUTTER and resultant flight surface failures with such engine installations.

I have installed the 1.60 at my discretion which is NOT a recommended power plant for the RB as it was designed and as such I assume ALL risks associated with that choice. But my decision is born out of EXPERIENCE.

I have insured that I have GAPLESS hinging on ALL flight control surfaces and as near to zero play in any of the pushrod systems as possible.

I can confirm that when using the supplied nylon horns and clevises, there is more unwanted play in the control surfaces than I wish and thus I replaced these components and put new horns and clevises and can now only detect the servo gear train play.

I will say that if installing the suggested motors, all kit components supplied should be satisfactory as tested by TT. However, when increasing speeds, these components need to be looked at closer.

I will close by saying that I'm very pleased w/ my RB and the 1.60 engine combo and that I have taken the precautions fore-mentioned to insure success but having said that, the incident in which my gear turned out of the wing on the test flight landing (as well as others who have experienced the same thing) was DUE SOLELY to a LACK of SUFFICIENT gluing and leads me to assume that the folks that have suffered stab failures on airframes with kit specified engines is possibly the result of the same condition.

The TT RB is a good product as designed and I recognize that when designing and manufacturing for the masses, they have done it right. For me, I just do not follow the herd, never have and never will.

It would be great to see a NAVY version of the F8F offered as well.

BR

I agree with you Vampire, course I am one of those guys flying a Funtana .90 with a Saito 1.80 in it! If you stretch the envelope, you build accordingly. If you break your airplane 'cause you didn't follow the recommendations, or didn't build it to accommidate the equipment you wished to use, don't whine about parts falling off of it in flight. I dunno how many Funtana .90s have went in because the pilot/builder didn't equip/inspect the plane properly before it was flown. I haven't gotten to the linkages yet but when I do I will be looking at the hardware and replacing any that does not meet MY standards, which are quite high. By the way, did you install a pump on your 1.60? (forgive me if I asked this already, most of the people I know who fly this powerplant use a pump on it. Me, being new to the big two stroke idea, don't have a clue)

cstevec, My O.S. 1.60 FX is not pump equiped. It runs beautifully as does the same engine in my GP GB-R2.

BR
Kerry S.

Vampire, which horns and clevises did you use

blohmvoss,

First, I cut and installed 3/4 sq. x 1/8 thick plywood horn mounting plates and imbeded them into the bottom of the Ailerons. Recoverd them with Ultracoat film, then I installed Robart #331 Super Ball Link horns and used the bolt-on clevises supplied with these horns on both the Robart horn AND the servo output arm. NO PLAY NOW.

For some reason the holes in the Nylon Aileron horns where sloppy when mated to the supplied clevises and the servo output arm which implies that the clevis pins where metric and smaller than lets say a DuBro 2-56 clevis.

All other surfaces where install with kit supplied components.

BR
Kerry S.

Thanks for the tips Vampire