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Nitro models pusher Bobcat?

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Old 11-09-2009, 05:55 AM
  #3876
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Default RE: Nitro models pusher Bobcat?

Unless you can add a thrust tube after the fan, Ducted fan setup is not much use.
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Old 11-18-2009, 10:51 PM
  #3877
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Default RE: Nitro models pusher Bobcat?

Heres my new (to me) Bobcat. This is my first Nitro powered anything, I have been flying both airplanes and helis for 3 years now and finally decided that I want a fuel plane so I found this on Craigslist for 2.5 bills. Its got the TH .75 motor with a 11x7 prop and mostly Futaba servos.

I am using a DX6i and have it set up for spoilerons as mentioned earlier in this thread.
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Old 11-19-2009, 11:35 AM
  #3878
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Default RE: Nitro models pusher Bobcat?

Congrats, she sure is pretty! Glad to see you venturing into the dark side. I don't know your experience level but nitro has some distinct differences of its own and, the NP Bobcat can be a challenging plane to fly and land. I recommend you have an experienced glow/airplane person trim this bird out and help you get acquainted with her. That's my .02 and it's worth about what you paid for it.

Best of luck.
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Old 11-19-2009, 08:13 PM
  #3879
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Default RE: Nitro models pusher Bobcat?

Thanks, she is a beaut.

I have flown mostly low wing balsa war birds in the high side of 40" WS, mostly taildragger and have a few like my FW190 that are still pristine after countless flights.

So far I have only done high speed taxi test with the Bobcat and am still upgrading some of the hardware before I go to the field for the maiden flight. I will have some members give it the once over but plan on flying it myself. The videos I have seen of this plane landing make it look pretty manageable and do not look like it lands at a very high rate of speed all things considered.
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Old 11-19-2009, 08:21 PM
  #3880
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Default RE: Nitro models pusher Bobcat?

Just make sure when it's sitting on the ground it sits slightly nose up or it will never get off the ground, on take off it should lift off on it's own when it gets up to speed with little to no up. And landing you need to keep it nose up and feather the throttle to get it to settle down on the main gear, once the mains touch down cut the throttle and roll to a stop. Really a fun plane to fly but it doesn't like slow flight so keep up the speed and have fun.

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Old 11-19-2009, 08:50 PM
  #3881
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Default RE: Nitro models pusher Bobcat?

Yea thanks for the tips, I have read this entire thread over the last 2 weeks and have set up the plane as you have all said.

I am not too worried about actually flying it or landing it, more about the motor not dieing. I have been doing taxi test and when I am bringing it back to myself I have experimented with different trim setting for the low idle and so far it has not died since doing that. I do have to then set the trim all the way down and hit the kill button to stop the motor but I have seen other pilots do that also so I guess its normal. []

I still need to get a tach and temp gauge and double check the needle settings but hopefully by next weekend it'll be up in the air.
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Old 11-19-2009, 08:57 PM
  #3882
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Default RE: Nitro models pusher Bobcat?


Quote:
ORIGINAL: 1320Fastback

Thanks, she is a beaut.

I have flown mostly low wing balsa war birds in the high side of 40'' WS, mostly taildragger and have a few like my FW190 that are still pristine after countless flights.

So far I have only done high speed taxi test with the Bobcat and am still upgrading some of the hardware before I go to the field for the maiden flight. I will have some members give it the once over but plan on flying it myself. The videos I have seen of this plane landing make it look pretty manageable and do not look like it lands at a very high rate of speed all things considered.
This is all true... just remember it flies like a jet so think like a jet and you'll be fine. True enough, it's not the easiest plane to fly but it's not as much a handful as many seem to think... IMHO ...and read Dauntae's post twice. good luck.
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Old 11-20-2009, 05:13 AM
  #3883
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Default RE: Nitro models pusher Bobcat?

The main difference between IC and Electric is with IC you do not get instant power when you open the throttle and the possible trim change as fuel is used, other than that they fly the same, in fact a big Electric Warbird is much harder to fly than this thing and when you land its lighter and more manouverable.

I fly a Com-ARF 2.12M Extra on a Pletanberg and 10S and the only difference between it and a petrol powered version is the weight and speed when landing, you have to land faster with the Electric version.

Mike
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Old 11-20-2009, 10:05 AM
  #3884
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Default RE: Nitro models pusher Bobcat?

Hey all HI.... All hte info here has been GREAT!!! Thanks to the answers from my questions my first flight with the Bobcat was succesful. I bought it used with no instruction. I have flown it several times since andit is a blast. I have found that a decent approach and it practically lands itself. Take-off is very straight forward also. It does fly fast and track beautifully. Have not pushed it yet other than loops and a few rolls. I like it too much to risk a crash. Thanks again.
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Old 11-21-2009, 07:14 PM
  #3885
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Default RE: Nitro models pusher Bobcat?

So I take my Bobcat out to the field after working on it into the wee hours of the morning. I replaced all the cheap hardware, rebuilt some of the servos and ran longer extensions where two shorter one had been used together before.

Anyway I am mentally ready to fly this thing and the weather is perfect. I fuel it up and just then I realized I had the tractor-prop still on the plane from tuning it the night before....Dooh, maybe next weekend.
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Old 11-21-2009, 07:23 PM
  #3886
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Default RE: Nitro models pusher Bobcat?

after tuning it with the tractor prop, richen it up a little because it won't have as much cooling with the pusher prop. You don't need it slobbering rich, but a little thicker smoke trail would be good for a little extra protection from over heating.

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Old 11-29-2009, 08:30 PM
  #3887
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Default RE: Nitro models pusher Bobcat?

Finally flew it today, met a friend at the field before sunset and we had the whole place to ourselves.

The maiden went ok, I needed to dial in a LOT of down elevator to get level flight and only 2 clicks right. The engine doesn't seem to be happy in the low-mid range so the approach went from idle with a nice glide slope but going to end up short to way too much power and ballooning up then back to idle with a nice glide slope till I made it to the runway and she settled in. The gear is very flexible especially on a pack dirt runway.

The second flight was worse. The takeoff was fine and did a few high speed passes and rolls. Coming in for the landing I was going to be long and my spotter said "go around" I gave it full throttle and she climbed out nicely, turned down wind and the motor starts to sputter and eventually dies. I remember asking "should I turn" and he said "no ditch it in the field". I realise that this is the right thing to do as trying to make a 180 degree turn at low level was not going to end well so I laid her down in the field which is plowed high grass.

When I drained the fuel out it was about 3/4 full so I know it wasnt that.

End result, tore out main landing gear, tore out front gear and bulkhead and stripped one aileron servo.

In the end if was FUN, this is my first Nitro and sure I have some work to do but I am hooked
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Old 11-30-2009, 11:14 AM
  #3888
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Default RE: Nitro models pusher Bobcat?

Sounds like your low end may have been a little lean. I have a motor on a Kadet senior that was doing the same thing recently. After adjusting the high needle thinking that was the problem and getting no good results. Someone suggested trying to richen the low instead. I usually tune my low needle so that it is 1/4 turn rich from where it lean boggs..

Don't give up though, these are fairly easy fixes. Like working on a jigsaw puzzle.



Shane
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Old 11-30-2009, 03:22 PM
  #3889
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Default RE: Nitro models pusher Bobcat?

Sounds about right Viper.....

Btw Fastback... hate to do it to you but pics are mandatory....[>:] Tore out retracts or fixed gear? Every time I've tried a short turn to final on a ds it's gone less than perfect. Some worse than others but with this plane especially, I'd say you did right to keep it level and slide it in... imho. Well, what are you doing here? Go fix it.
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Old 11-30-2009, 09:08 PM
  #3890
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Default RE: Nitro models pusher Bobcat?

Alright heres some pics, I am stopping by the LHS after work tomorrow to get some balsa, it does not have retracts and in fact I plan on removing the wheel tubs as they are all broken up an just making the bottom smooth and recovering it.

My spotter said he though it was rich as he saw smoke coming out of the exhaust but I don't remember. The motor is on the back burner till the plane is fixed.

Its really not that much damage and of that I am glad. The front doenst look bad undereath so I didnt take a pic of it.
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Old 12-06-2009, 12:44 PM
  #3891
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Default RE: Nitro models pusher Bobcat?

Here's the parts and the pre-fitting. I plan to use some landing struts from a 3D plane instead of the stock wire, that is what the blocks are for.
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Old 12-30-2009, 12:10 PM
  #3892
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Default RE: Nitro models pusher Bobcat?

Quote:
ORIGINAL: tbrewsterrc

Has anyone used a Super Tigre 90 on the Bobcat 51. I am preparing to get mine built and have some concern about the engine being too large. The G90 really doesnt weigh much more than the OS Fx .61. Opinions,???? Thanks, Tom
I used the st90 on the kee cat, a larger plane. it will work with a graupner 11x8, but run it rich a bit as it will be revving 14500 rpm but it motored pretty good. you should get 110mph on the bobycat

Dub jett sells a pusher pipe/ ultrathrust muffler.. gave it 1000rpm
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Old 12-30-2009, 03:20 PM
  #3893
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Default RE: Nitro models pusher Bobcat?

Hey all... First of all thanks to everyone's help. My first and subsequent flights have been great. I am running an OS .61 on my Bobcat. I might try the .90 I have sitting around, and see how it does.

I have purchsed Eagle tree's "how fast" system. I tried it out on another planes and it worked very well. Soon as the weather gets a bit warmer around here I will let you know how fast the Bobcat flies with prop changes. Any suggestions on props let me know and I will try them and let you know. FYI mine does not have retracts.
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Old 01-04-2010, 11:27 AM
  #3894
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Default RE: Nitro models pusher Bobcat?

I can't find the screws in my hardware package that fit the blind nuts in the stabilizer. And I'm also missing the blind nuts for the engine mounts. Other than that I'm good to go.
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Old 02-07-2010, 04:47 PM
  #3895
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Default RE: Nitro models pusher Bobcat?

Here's another variation designed for a 44 size turbine.
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Old 02-13-2010, 08:47 PM
  #3896
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Default RE: Nitro models pusher Bobcat?

Hi guys, i have finnished and flown my bobcat now and i am very impressed with the flight envelope, i am running an asp52 with a weston pusher pipe turning an apc 10x7 i havnt tached it yet but it howl's and also spring air retracts. landing was the one thing i was worried about after reading all the stories of bouncing etc but i found the landing to be a breeze with a nose high attitude ( it realy looks cool) the only issue i have is take off, it gets plenty of speed and really leaps off the ground at 45+deg and it is quite scary even pushing down elevator dosent help during the initial lift off, after a few seconds elevator response becomes good and you can level off ok, what have people done to minimise this tendency? i do have a positive angle of attack when sitting on the ground. i have used about 1/4" reflex on ailerons for landing should i try this for take off.
Thanks Greg
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Old 04-03-2010, 09:52 PM
  #3897
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Default RE: Nitro models pusher Bobcat?

Hello all, I know that somewhere in the 156 pages of this area there is a post wher someone said to balance the plane but unless I have to I would like to avoid reading all the pages again and have someone tell me where to balance the plane please.

Brad
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Old 04-03-2010, 10:33 PM
  #3898
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Default RE: Nitro models pusher Bobcat?

Heyhas anyone used EDF for these yet?? If so how does it fly
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Old 04-04-2010, 01:27 AM
  #3899
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Default RE: Nitro models pusher Bobcat?

CG is 10.3" from the leading edge where it meet the fuselage

No one has done a EDF to my recollection.
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Old 04-04-2010, 04:38 AM
  #3900
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Default RE: Nitro models pusher Bobcat?

EDF has been done, with a great deal of modification by taking off the tail booms etc, have a look through the early part of the thread.

Mike
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