Extreme Speed Prop Planes Discuss the need for speed with fast prop planes (Screamin Demon, Diamond Dust, Shrikes or any REAL sound breakin'''' plane)

Its Bobcat nice

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Old 07-16-2007, 04:56 PM
  #301
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Default RE: Its Bobcat nice

IMO a P80 will be way overkill in a plane this size. A Wren 54... ok, with the reduction in fuel capacity and engine weight, that will probably work.

Do the math with a RTF P80 and two litres of fuel... you'll end up with a brick.

I wasn't aware that Weston did custom work. That's a VERY neat pusher setup you've got there!
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Old 07-16-2007, 05:52 PM
  #302
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Default RE: Its Bobcat nice

[sm=cool.gif] Thanks for the reply Bud... I can't wait to hear of your flight experience with the Falcon, can't say enough how good that plane looks... I'll have to order soon... From what I can see it should be great with the Wren-54 on it, just right... OK I'll let ya get back to getting it all together, looking forward to any info at all about your progress...
ENJOY & HAPPY FLYING!!!
MOJO
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Old 07-28-2007, 12:07 PM
  #303
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Default RE: Its Bobcat nice

OK Plane is on the way Falcon-120 I am thinking of putting the SK-1.30 on the back before I go with my Wren MW54
Can anyone tell me from experience if it's good to go with a 3-bladed prop or what do you suggest....The motor calls for a 16 X 8 for normal operation but for the pusher application I am not sure, I have e-mailed them as well...I will post their suggestion...
Thanks Guys!!! Happy Flying!!!
MOJO
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Old 07-28-2007, 12:21 PM
  #304
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Default RE: Its Bobcat nice

....you need to set the plane up and see how big (diameter) prop you can use....

....they won't take big props.

FBD.
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Old 07-28-2007, 12:29 PM
  #305
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Default RE: Its Bobcat nice


Quote:
ORIGINAL: Flyboy Dave

....you need to set the plane up and see how big (diameter) prop you can use....

....they won't take big props.

FBD.
Thank You FBD, I will wait to get the legs on it and see what's available... I'm sure it will be a 3-Bladed Prop just curious about what size it might be to replace the required 16 X 8 required for the engine in regular tractor use...
OK Enjoy...
Mojo
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Old 07-28-2007, 12:49 PM
  #306
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Default RE: Its Bobcat nice

....you need some pitch for some speed as well....

....maybe something in a 14-8 three blade would work.
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Old 07-28-2007, 01:07 PM
  #307
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Default RE: Its Bobcat nice

I have a 14x7, Master Airscrew 3 bladed pusher on mine, but I am about to refit the legs and I will check the ground clearance over the next few days.
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Old 07-28-2007, 01:14 PM
  #308
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Default RE: Its Bobcat nice

Thanks for the help Winch & FBD and all the Guys....Looks like this is going to be a great forum... I will probably buy a few different props and give them all a run...
Happy Flying Boys!!!
Mojo
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Old 07-30-2007, 07:27 AM
  #309
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Default RE: Its Bobcat nice

Are 11x10 tractor pitch props made?
This is to go on ST 61.
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Old 07-30-2007, 07:40 AM
  #310
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Default RE: Its Bobcat nice

G'Day Mate!!! APC has them, Tower sells them, Just type in 11 X 10 propeller in your search bar and many options came in...
Happy Hunting & Flying...
Mojo
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Old 07-31-2007, 12:49 PM
  #311
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Default RE: Its Bobcat nice

Hey guys what do you think?

I have a new saito 100 laying around, and I like the richmodel KeeKat.

Could we make a speedster from that, what prop would you all recommend. 14x8? is that too big to hit the ground. Cut down 16.10? any opinion is a good one at this point.

I want a jet trainer. I will later put a 44 or something on it, or a detuned 54 turbine if this works out.
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Old 07-31-2007, 01:05 PM
  #312
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Default RE: Its Bobcat nice

Hi guys. I had my KalmKat back on it's wheels today to measure prop clearances etc. From the centre of my prop driver to the ground is 22cm. However, ensure that when you mount the engine you mount it far enough back so the prop you choose will clear the t/e of the wing, which is raked sharply back.

Retracts fully operational today. Semi scale cockpit underway and a vacform company is looking at making me a replacement clear canopy instead of the horrid orange jobbie!.

Pete Tindal control horns and links on their way, Graupner whip aerial ready to be installed.

I'll keep you upto date with progress.
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Old 07-31-2007, 02:17 PM
  #313
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Default RE: Its Bobcat nice

What is a "Kalmcat"?
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Old 07-31-2007, 03:57 PM
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Default RE: Its Bobcat nice

Its the big Bobcat, also known as the Falcon 120, as seen earlier in this forum. I've got one and Grumman has his on the way.


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Old 08-03-2007, 01:41 AM
  #315
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Default RE: Its Bobcat nice

guys where can i find an 12x8 pusher?
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Old 08-03-2007, 05:41 AM
  #316
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Default RE: Its Bobcat nice

Hello Type in your search box: APC 12x8 pusher and watch all the choices come up....
ENJOY!!!
Mojo
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Old 08-03-2007, 08:48 AM
  #317
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Default RE: Its Bobcat nice


Quote:
ORIGINAL: Grumman

Hello Type in your search box: APC 12x8 pusher and watch all the choices come up....
ENJOY!!!
Mojo
You got a link? the only APC 12x8 pusher I can find is electric.

Thanks, Terry
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Old 08-03-2007, 09:01 AM
  #318
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Default RE: Its Bobcat nice


Quote:
ORIGINAL: still4given


Quote:
ORIGINAL: Grumman

Hello Type in your search box: APC 12x8 pusher and watch all the choices come up....
ENJOY!!!
Mojo
You got a link? the only APC 12x8 pusher I can find is electric. www.ntchobbies.com They have a Master Airscrew.... MOJO


Thanks, Terry
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Old 08-03-2007, 12:48 PM
  #319
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Default RE: Its Bobcat nice

I checked out your link, I don't see any 12x8 pusher props, even by MS.

Thanks, Terry
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Old 08-03-2007, 01:12 PM
  #320
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Default RE: Its Bobcat nice

Try this Terry... GP312080 12x8, 3 Blade Prop xyr $ 14.80 IN STOCK www.hobby-lobby.com
Hope this helps...
Mojo[:-]
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Old 08-03-2007, 01:32 PM
  #321
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Default RE: Its Bobcat nice

Well, the numbers are the same but it's a three blade. That is not going to work in place of a two blade of the same diameter and pitch. At least I thought that Tony was looking for a two blade 12x8 pusher. Maybe I'm wrong. He will have to chime in and let us know.

Blessings, Terry
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Old 08-07-2007, 11:46 AM
  #322
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Default RE: Its Bobcat nice

Hello,

I have a Bobcat running with a OS61FX (with a graupner 12x8 pusher). The speed is ok, but the plane drops the nose (much!) when I back off on the throttle. I have tried lifting the two FRONT screws on the engine (2 mm at a time) so the front of the engine now is approx 8 mm higher than the end (to give more "down" thrust on the prop) but this does not cure it ! It helps a little, but the plane still drops the nose when removing throttle.
I have mounted the engine approx 10 mm above the woodblocks in order for it to clear the fuse, can this be the error (thrustline offset)

Also I think the plane has a tendency to "stick" to the runway during takeoff, it rolls forever, and needs a lot of up elevator to get it off the ground (and then one have to be quick to ease of on the elevatpr again !)

I have mounted a new landing gear at approx the place as the originals were (they were torn off in the first "landing" attempt [>:])

Regards,
Carsten
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Old 08-07-2007, 12:17 PM
  #323
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Default RE: Its Bobcat nice

Carsten,

I think you are going the wrong way with the thrust. Raise the rear of the engine to push the nose up (just like the turbines). The other thing may be that the larger props are mixing it up with the stab creating issues. You may want to try a smaller engine with a smaller prop to test this theory.

Mark
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Old 08-07-2007, 12:46 PM
  #324
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Default RE: Its Bobcat nice

I assume you have the non-retract model. There must be a difference in where the main gear are located between the retract version and the non. I have the retract version and if I don't hold down elevator on takeoff roll, the nose wheel bounces up and down all the way down the runway. I would say to bend the gear forward a bit to see if it will rotate better. I think I have read that some of the guys reversed the gear to get it more forward.

By the way, where did you find a Graupner 12x8 pusher? I can only find the 11x8.

Blessings, Terry
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Old 08-07-2007, 12:51 PM
  #325
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Default RE: Its Bobcat nice

Mark,

maybe you are right, at the same time I changed the thrustline (by recommandation of one of the "old" guys at the flying field) I also adjusted the CG as it was way off (tailheavy)

Regards,
Carsten
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