RE: Nitro models pusher Bobcat?
 

have flown with 14-7 3 blade trimmed on my 91 fx still looking for more speed bought a 16-10 3 blade pusher cut it down enough to clear booms waitin for hell to unfreeze here to try!

RE: Nitro models pusher Bobcat?
 

Do you have any experience with this engine, O.S. .50 SX-H Ringed Hyper? I think this is a good option, because, thios engone has a lot RPM and Power.

RE: Nitro models pusher Bobcat?
 

Ive never dealed with nitro models, can someone who have tell me how long it took to get your model ?
this is next on list and my list is now due.:D

RE: Nitro models pusher Bobcat?
 

Im going to stick a TurbaxIII fan on this thing with a picco .80<---good power with a small size
rather than my K&B.82<-----good power but somewhat heavy.

RE: Nitro models pusher Bobcat?
 

SAW ON ANOTHER THREAD THERE IS A NEW FALCON 120 RETRACT READY (AKA UPDATED BOBCAT) FROM NITRO, WHERE CAN I FIND MORE INFORMATION ON THIS NEW MODEL ?

THANKS !

RE: Nitro models pusher Bobcat?
 

Carlos,

OS made the same engine in an airplane version. They are discontinued but you still may find one if you search hard enough. The new 55ax has similar power.

Mark

RE: Nitro models pusher Bobcat?
 

MARK, the Heli Engine has more power and rpm than the airplane engine. I saw this on www.osengines.com

What do you think?

RE: Nitro models pusher Bobcat?
 

I think they must be measuring the Heli version with a non-baffled muffler. There is only one part listed for the liner which means the porting is the same. The carb could have a minor difference but I doubt it. The main issue is the crank, since you want to put a prop on this thing. The Air version is your best bet if you can find one.

Mark

RE: Nitro models pusher Bobcat?
 

My hyper 50 cranks in my rappy. 17k 10deg pitch

RE: Nitro models pusher Bobcat?
 

hey guys

where is 0 degrees pitch on elevator surface. Is it
when bottom of surface is straight with bottom of stab or centered
between curve of top of stab and flat side of bottom of stab

thanks!!

RE: Nitro models pusher Bobcat?
 

I was wondering this myself. Technically the neutral position should be in line with the flat bottom of the stab but it seems as though most everyone that has flown theirs had to add a little up trim. I've set mine so neutral is slightly up from the flat bottom of the stab.

RE: Nitro models pusher Bobcat?
 

Generally it is at 0 degrees angle of attack, so for a flat bottom airfoil like the bobcat stab, the bottom surface of the elevator would be flat with the bottom of the stab.....for a symetrical airfoil, it would be centered between the top and bottom surfaces.... This will not necessarily give you hands off level flight trim setting since there are other factors involved. Chances are pretty good that after the first flight you would be adjusting this neutral position anyways.......

Just wish this ice age would end, so that I can fly mine !!!!!

RE: Nitro models pusher Bobcat?
 

Well I completely removed the original canopy paint by carefully wet sanding with 400 and repainted with Rust-Oleum gloss white for plastic. Turned out great but was a PITA. I also wet sanded the Green stripe off the fuse. [:'(] Here's a couple of pics now that she's all done. I took an earlier idea that someone posted about using an old aluminum exhaust header for a muffler deflector. Had one from an old T-Maxx, cut the flange off and JB welded onto the muffler outlet. Perfect fit, great suggestion. Don't know if it was absolutely necessary but it can't hurt. I used two 6-32x1 socket head screws and blind nuts to secure each wing instead of epoxy. I tossed the 5/32 anti-rotation rod and epoxied one blind nut into the existing wing root anti-rotation hole with a 1" square of 1/8" aircraft ply and another as far forward as I could get it. I also epoxied 1" squares of aircraft ply to the inside of the fuse at each bolt location. This secures the wing rock solid and also permits removal of the fuel tank without removing a wing because the rod is not in the way. I also installed a landing gear strap to the underside of each wing toward the rear where the wing meets the fuse. With an OS .55AX, the receiver and a 5-cell pack right behind the nose gear block, stock rudder and elevator servo locations, it balanced out perfect at 10.5" without adding any weight at all. AUW is exactly 7 lbs. Mains are 2 3/8" behind the CG at 10.5". I'm not a cold weather flyer so it'll have to wait til Spring to get airborne. Despite all the added work it was a fun project. I do have a question for those of you that have flown; How much throw on high rate elevator is needed for landing? I can get a little more than an inch up, I think this should be enough.

RE: Nitro models pusher Bobcat?
 

You're welcome....

RE: Nitro models pusher Bobcat?
 

Hi Guys,

A friend sent me this link for a muffler which is designed for pusher engines, hope it's useful.


http://www.westonuk.co.uk/index_090.htm


Regards,

Sarah

RE: Nitro models pusher Bobcat?
 

I'm thinkin a nice Mousse can muffler would be a way to go compared to the 40 pounds. Then again, 130 dollar airplane, 130-170 to higher for a motor, 160 for a flight pack, 150 for Retracts, whats another 60-74 bucks? This cheap airplane is starting to add up!

Makes me realize just how far I have to go before I can consider flying Jets for real. Whens the next lottery?

RE: Nitro models pusher Bobcat?
 

While the muffler shown in Post #1156 looks great, the exhaust outlet is probably no more than 2" away from the prop. Directing the concentrated exhaust right into the prop doesn't seem like it would be the most desirable setup. The prop slinging all that exhaust oil has got to make a real mess. A stock 2-stroke muffler with some type of deflector would seem to at least give the exhaust a chance to disperse before some of it gets to the prop.

RE: Nitro models pusher Bobcat?
 

Am joining the Club by ordering a Bobcat.
Can someone please give me the empty weight of the model (everything except motor, radio etc)?

Am planning to electrify my Bobcat and need to play with Motocalc to find a comination that works.
It would be usefull also if someone could give me the rpm of a glow motor to compare with.

Thanks
// Johan

RE: Nitro models pusher Bobcat?
 

I will look for my spreadsheet, I weighed everything thinking just like you that I might electrfy this plane...I have a tower .75 on mine.

RE: Nitro models pusher Bobcat?
 

omega-RCU,
I did not weigh all the pieces as they came out of the box but the finished AUW of mine (glow) is 7 lbs. even. Minus the servos, battery, receiver, engine, muffler, prop, and fuel tank I'd say it was between 4.5 and 4.75 lbs.

RE: Nitro models pusher Bobcat?
 

The prop only passes in front of the exhaust outlet twice per revolution. leaving (depending on the style of prop used ) something like 330 degrees of revolution where the exhaust would shoot straight back and not hit anything. In fact it would be possible, since it is a 2 stroke engine, to position the prop so that the blade has just passed the exhaust opening just as the exhaust pulse is leaving the outlet give the exhaust gunk a clear shot through the prop disc and past the tail booms. Sounds good in theory, now someone has to test it...... :D

RE: Nitro models pusher Bobcat?
 

Johnnyjet,
I like the simplicity of your retracts. What brand/model retracts are they? WHat did you use for the front wheel retract?
You mentioned a "trimmed" 3 blade, did you trim down the original? How much was trimmed off?

RE: Nitro models pusher Bobcat?
 

Mine is less than an inch from the prop and after a flight the prop is almost dry. I watched the exhaust from idle to full and it goes straight through and what does hit the prop is likely thrown off by centrifugal force. It's a non-issue I try not to over analyze.
Rich

RE: Nitro models pusher Bobcat?
 

Dealer in Norway.

Just want to inform that it is a dealer in Norway as well selling Bobcat 50. The webpage is only in Norwegian still, but you are welcome to e-mail us in English for purchase. The price for non-Norwegian customers is abt $230,- pluss shipping.
Website is: http://rcnet.no and the add for bobcat you fin here: http://rcnet.no/b2b/index.php?cPath=26

Brgds
Harald Magne
Rcnet AS

RE: Nitro models pusher Bobcat?
 

What's the difference between the Springair 302's and 305's?