TUMBLER

My Feedback: (13)

Yeah I saw the hole but didn't see a blind nut. I guess it fell out or was never put in. Just one bolt should do it right?

HeliTB

Tumbler...There were two holes, well actually 4 holes on the wings, that is on my Bobcat anyway.

1. Wing Tube (thick hollow) - Rear
2. Anit-Rotation (thin solid) - front
3. Blank hole
4. Hole with blind nut (it's kind of recessed deep).

TUMBLER

My Feedback: (13)

Ok I will have to take a closer look. I guess you are are bolting the ing on before putting the fuel tank in then right. Can't imagine ant of ther way to do it. The 1.20 has a hatch on the bottom, so I guess you could cut a hatch.

BillS

I added a small doubler inside the rib and used a 1/4 - 20 nylon bolt. Drilled a small hole in the fuselage to locate the bolt and then tapped the rib. Recollection is the hole was about 1 3/4� from the leading edge of the wing. Have not needed to remove the wing.

Bill

HeliTB

Yes...I mounted the wings before bolting down the tank, so that I could run the wires inside. What I did was take my dremel and made to half moons in the bottom of the former where the tank passes through right above the anit-rotation thin bar, so the wires don't get pinched by the tank.

sbrackets

Sounds like a lot of stuff to think about when building this Aircraft. My question is ! Can the wings be removed easy for transportation reasons if not glued?

Thanks, Jim

HeliTB

Even with the wings being removable, you won't want to remove them for transporting. It will take you about 30 min to 1 hour to re-route all the wires back to the RX and re-install the tank. I wouldn't glue them if you can help it. You will want the luxury of removable wings for maintenance or repairs.

BillS

Agreed that removing the wings for transporting would be time consuming and probably should be avoided. Removal for repair is desirable. You might want to test fit the airplane in your car or van before making a decision. It is a tight fit in a Honda van.

My servo wires enter the fuselage 2� in front of the tank at an elliptical hole in the rib.

After a few flights all the fuselage formers are loose. You might want to consider epoxy and triangle stock reinforcement.

Bill

HeliTB

Here are pics of my Bobcat 50 at our flying field before the maiden.

TUMBLER

My Feedback: (13)

The guy I am building the Bobcat for wanted the rudder servos on the inside of the boom, so I thought I ould post a pic in case anyone wanted to do it like this.

Tumbler

Boomerang1

LOL! I bought mine second hand & didn't even realise mine had been modified!

I have started fitting a belly mounted airbrake on mine to make it easier to land at our short strip. - John.

HeliTB

Boomerang1...Have you flown it with the turbine yet? I can't remember seeing a maiden post a few pages back.

Tumbler...Looks good, I wish I would have done that for asthetics.

TUMBLER

My Feedback: (13)

As far as asthetics, yours lookdarn good already the way you changed her up!

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My Feedback: (13)

Well I check the wings, and I do not have any holes for wingbolts. The latest design must be for glued wings only. Not to say that can't be modified, but they don't include the holes or blindnuts.

sbrackets

No, mine either. I checked my kit yesterday. Plane is still in the box. I was hoping that the wings were made for wing bolts, Oh well!
I believe I'm going to just epoxy my wings to the fuse and be done with it. I'm not going to make this thing more trouble than I have too. Even thinking more about installing the fixed landing gear instead of going with retracts. Keeping it cheap. Heck! the plane was only $99.00 bucks. If I go with retracts they cost more then the plane, In fact everything else cost more then the plane.
I might just stay on the cheap side on this build.

Boomerang1

Yes it's flown, 2 weekends so far & 5 flights. It's very fast at full noise even with the earlier 8 pound Wren 44. Most of the flight is at about 1/2 throttle on the stick with plenty up it's sleeve.

I cannot say it has unlimited vertical performance because I only let it fly straight up as far as I can comfortably see it, but it's still climbing fast at that point. Climb after take off is at about 45 deg & accelerating.

The bit I'm concerned about is landing on short fields. You have to make a very shallow approach with the nose up & the engine at idle (55,000 RPM!). The earlier Wren 44's have a slow spool up time so if you have to go around the engine takes a while to develop usefull thrust. - John.

HeliTB

Boomerang1...Thanks for the info. Here's my second flight report.

Flight Report
Weather conditions were good about 85F degrees, winds about 7 to 8 kind of cross the runway, but at an angle.

All repairs completed from maiden flight. Engine (OS 55 AX) was richened a few clicks, it was dying about 70 yards (210 feet) down the runway. After that lined up again for lift off. My Bobcat ran about about 85 yards (255 feet) before launching into the air, almost vertical as on my maiden. I don't like that. As I mentioned in my initial flight report, I believe my Bobcat is nose heavy making it difficult for the nose to lift without giving an extreme amount of up elevator to get it off the ground. I was ready for the leap so it wasn't as vertical as the initial flight.

After leaving the ground and levelling out, hit the switch and brought the retracts up. Boy does this thing look cool with the retracts up. Was cruising around just to continue to get the feel for this puppy. Did I mention this thing is fast. Well this thing is fast. I don't know why anyone would want to go faster with a Tower .75, well I kind of know why, but don't understand why.

I performed a few aerobatic manuevers. Roll rates are insane on high rates, so insane I'm not sure was I finish rolling whether or not I right side up or up side down. That's scary. Roll rates are extremely fast or low rates. Basically I come down the runway WOT and then snatch up elevator, half way up I would give right aileron and do somewhere between 10 to 15 rolls before hitting the top of the loop. Depending on right side up or down, I would spin once more on the down part of loop and level out.

Now for the imfamous landing. I believe someone has this as their signature, "Take offs are optional, but Landings are Manadatory." Since it was the second flight I didn't want to over do it. Flick the retract switch and did a low pass to verify that they did indeed come down. Began my approach/line up passes, and finally saw one I liked and began my landing. Our runways are about 10 yards (30 feet) wide, I was lined up about 10 to 12 feet from the closes side of the runway to me. As I got closer to runway, I would say about 4 feet off the deck a nasty cross wind came up, I was thinking not now, my AOA for landing was near perfect. This moved the the plane to about 4 feet from the high grass. The plane continued to weatervane into the wind just as the rear wheels touch the ground after about 2 feet the nose wheel touched down. At this point I was not even 1 foot from the high grass, the right main caught the high grass right in front of mee and then the nose wheel caught the high grass. Once that happened the Bobcat stop and flipped over, motor still running. I hit the kill switch to shut it off. Now for the damage:

Damage Report
1. The came apart toward the leading edge, I think this was due to the hot glue not really securing the front screw brackets, nothing epoxy can't fix.

2. Bent right main and nose wheel struts shaft, nothing a hammer can't straighten.

Flight lasted about 6 mins, I emptied the tank on the flight station. The amount I removed would have lasted about 1 more minute. All in all I consider both successful flights, with eventful landings. I will have the wing bracket epoxied back in and retract shaft straightened by this evening 8/15. I think I'm going to put 3/16" music wire in my retracts instead of the struts, since the wire may be a little more forgiving on the landings until I get a better feel.

Hope I didn't bore you. Just wanted to be thorough for any trying the Bobcat for the first time. I must say OPJOSE warned me that the Bobcat is quite different than any other plane in my fleet. Now I know exactly what he means.

Boomerang1

Sorry to hear you bingled your Bobcat, I bough mine damaged after a similar landing accident.

I have almost finished fitting an airbrake to the belly of mine & hopefully will try it out tomorrow. It just needs a tidy up & it's ready to go. - John.

HeliTB

Boomerang1...Thanks for the kind words. It's repaired. I should have taken the advice in this forum to put epoxy on everything I could see before assembly. That hot glue they use ain't worth two cents.

BillS

I have 16 flights with an old OS .45 running in reverse. Although it flies OK after getting up to speed a .45 is not enough engine for the Bob Cat. The airplane is 8 pounds with fixed gear and would be much more fun to fly with a .60 or .61 engine. Landings are easy and can be high alpha. Roll out on grass is reasonably short. LHS’s doesn’t stock pusher props so I am looking for a .60 or .61 that can be run backwards. Stall at altitude appears to be straight and gentle.

Reminds me of the early 1950 era jets that need the height between the flight deck and the sea to get up to speed.

Bill

sbrackets

Hey Guys
Well I didn't like the idea of using a red canopy on my Orange Bobcat so I purchased a small 3oz. can of TAMIYA TS-12 Orange spray paint. It's made for plastics, and worked like a dream. It's a very close match to the Bobcat. I only had to paint the canopy frame orange, not the windsheld. I left that tinted. Now with the frame is painted orange the windsheld looks to be tinted orange. I was going to paint the windsheld black, but now there is no need.

I sprayed the outside surface of the canopy Orange, let dry for one hour, then sprayed a layer of clear. Looks nice now.
Here is a link to the type of paint used.

http://www3.towerhobbies.com/cgi-bin...&I=LXRS55&P=SM

Regards, Jim

sbrackets

Here are a couple pictures of my red canopy that I have repainted orange with the TAMIYA Orange spray paint TS-12. I think it's a pretty close match. Hey! It's better then that red.

HeliTB

I must say you did an excellent job.

opjose

Sorry to hear this... I too learned it the hard way.

I no longer "Fear the Bobcat" though... heh.

The spoilerons are a massive help getting the plane down.

I flew my little Bobcat 25 many times today after FINALLY wringing out a perfect electric power system for it. I'm runnning it with an 893KV motor using an 60A ESC, a 8x6E prop ( yup THAT small ) and a 14.8v 3700mAh 4S1P Lipo pack. AUW with battery 4lbs 3oz.

I had to resort to the small prop because when I first tested this setup ( 9x8 APC E prop ) I was drawing over 900watts at 59A, which is beyond my motor's thermal limit.

At any rate my little rocket was very difficult to get down, particularly because as you've discovered it doesn't do the transition to grass very well.

On my second flight I had spoilerons dialed in and the elevator deflected down with the spoilerons ( on a switch ). This was a perfect setup.

I had no problems performing a half dozen very "jet like" landings, all nose high, after I flipped the spoileron switch on.

It helped so much that I was able to bring the plane in on medium grass, something the little Bobcat really cannot handle, without any problems.
This little plane will NOT roll on grass of course, but with the spoilerons and the nose high attitude it settled to a very nice stop lightly pushing the blades down as it decended with no gear damage what-so-ever... much to my surprise.

So again, if anyone hasn't set their Bobcat for spoilerons, DO IT, you'll be glad you did.

Once you get the plane in the air and trimmed, take it high and immediately start practising flying it with the spoilerons ON ( it will go nose high during level flight... ) then start shooting approaches.

Better to learn how to deal with the plane with a full tank, then when it runs out of fuel or deadsticks!

Boomerang1

Well, the airbrake works fine, the ability to fly a steeper approach without the speed building up is a big help. I modified it a little from the first pics by arranging for a full 90 deg of deflection & I will now fit a fairing block at the front & dress the rear of it up to make it look tidier.

There was a little pitch up when it was deployed but it's easily handled by down elevator & as you approch to land you are on the elevator anyway so it's not noticable.

Time for some paint! - John.