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Nitro models pusher Bobcat?

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Old 08-28-2006, 07:36 PM
  #251
MarkF
 
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Default RE: Nitro models pusher Bobcat?

I flew mine this weekend . I converted it to electric and got one flight in. First off I used what I had laying around for power. Neu 1521 2y with 12s 1p 3700 evo batteries. This set up is a little to hot because I could only swing a 9 X 6 prop. It tacked out at 26000 on the ground and it felt and sounded really good but it just wouldn't get up and go once it was up in the air. I think you need at least a 10 inch prop at minimum but an 11 would be better. My cg was at 9 1/2 but I think 10 would be better. My batteries need to be all the way back as far as I could get them. I had to dremmel out all the bulkheads so they could slide all the way back to the wing spar rod. I got rid of the front wing rod and drilled it out to 1/4 20 to hold the wings on. I think this was the easiest way to secure the wings. She wieghed in at 9 lbs ready to fly and I felt she handled this weight with ease. Now I just need to get a different motor or less batteries before I can fly again.

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Old 08-28-2006, 07:59 PM
  #252
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Default RE: Nitro models pusher Bobcat?

Mark it sounds like your prop maybe flattening out at high rpm at 26000rpm on a 9x6 prop you should be able to make even a 12lb plane haul ass. Mathmatically speaking a 6 in pitch prop should be pushing air out at about 147 mph. What type of prop are you using?
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Old 08-28-2006, 09:35 PM
  #253
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Default RE: Nitro models pusher Bobcat?

I was using a regular apc pusher gas prop. I see SJN didnt like his 9 inch prop either. This air frame is going to need a bigger disc to get the performance we want. I also posted in this forum because some of the people wanted to put bigger motors and they wanted to know if it could handle the weight. I found this plane easy to land at 9 lbs. I will be changing my set up to handle an 11 inch prop.

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Old 08-29-2006, 11:45 AM
  #254
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Default RE: Nitro models pusher Bobcat?

For the question on the .75 engine. If it is a Tower .75 it will have a little less power than an OS .61, at least that is what I experienced on an Enforcer. I then went to an os .91, and it had about twice the performance. I will have the .91 powered Bobkitty flying in a week or so. Bob
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Old 08-29-2006, 03:06 PM
  #255
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Default RE: Nitro models pusher Bobcat?

I decided to go with a Saito 72 instead. It just fit better back there and sould swing a three balded prop easily. If that dosen't give me what I want I can alway do a little surgery and put in the 75 2S. I also have a 91 2S In another plane that could move over is necessary.

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Old 08-29-2006, 03:34 PM
  #256
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Default RE: Nitro models pusher Bobcat?

Quote:
ORIGINAL: bassman
I decided to go with a Saito 72 instead.
A 4-stroke in a jet-ish plane?

Dude, that's wrong, just plain wrong :-)
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Old 08-29-2006, 05:20 PM
  #257
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Default RE: Nitro models pusher Bobcat?

Well I'll tell ya, anything other than a turbine on a jet is kinda back woods isn't it. I think the real dirver on this one was the big 2 stroke muffler sticking the wrong way. I just like look of the four stroke on the plane better and the 72 should swing the 3 blade 11-7 without any problems.

Bassman
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Old 08-29-2006, 10:04 PM
  #258
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Default RE: Nitro models pusher Bobcat?

now i have never flown a jet with a 4s, but to each there own, and as we are all in this for fun! that's what it's all about!, right????
i think as long as it gets off the ground and fly's he's cool,
(good to go), it will sound funny, kinda like a small flying tug, but it will look like the rest, very cool.
just sound funny!

the plane looks great best of luck BASSMAN.

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Old 08-30-2006, 01:02 AM
  #259
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Default RE: Nitro models pusher Bobcat?

Bassman, I like it. I think four strokes sound killer and I do like the idea of the muffler. I have a saito 100 that would fit nicely on the back of one of these. I just wish I could find like a 10X10 pusher or 11X9 pusher. I had a saito 91 with a high pitch prop and that mustang was just as fast as my Shrike with my rossi on it. The only problem is the limited selection of pusher props. I emailed APC about it and have yet to hear from them. I would be cool if they would make some high pitched ones.


I do have a few of these kits, one has a Rossi 45 on it, the others are back up. However, i think one with the saito 100 would be cool.
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Old 08-30-2006, 01:13 AM
  #260
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Default RE: Nitro models pusher Bobcat?

it looks like Zinger has an 11x10 pusher that would be a good match for the Saito 100. Might have to try that.
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Old 08-30-2006, 04:10 PM
  #261
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Default RE: Nitro models pusher Bobcat?

I like the 4 stroke idea.

so I instaleld a Magnum/ASP 65 in mine.
I hope it performs better.
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Old 08-30-2006, 05:00 PM
  #262
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Default RE: Nitro models pusher Bobcat?

that looks cool. Let us know how it comes out.
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Old 08-30-2006, 05:29 PM
  #263
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Default RE: Nitro models pusher Bobcat?

How have you guys been handling the take down of the Bobcats for transport? Are you removing the booms only? Are you leaving the booms on the wings and taking the wings off? It makes a difference in how I set up the servo extensions coming off the boom servos. I really like to keep the connections to a minimum when I can.

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Old 08-30-2006, 05:32 PM
  #264
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Default RE: Nitro models pusher Bobcat?

hehe, mine just fits in my car in one piece.


a pic of my chipmunk in the trunk
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Old 08-30-2006, 10:19 PM
  #265
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Default RE: Nitro models pusher Bobcat?

I would really like to pick one of these Cats up. But Nitromodels can not give any ETA's as to the next shipment. Are there any fellow modelers out there with an extra BOBCAT 50 "YELLOW" kit that they would like to part with. Please let me know : jwmclean@dslextreme.com
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Old 08-31-2006, 04:07 AM
  #266
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Default RE: Nitro models pusher Bobcat?

Why not go the whole hog and put a steam engine in it ? (smirk). Paul.
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Old 08-31-2006, 04:29 AM
  #267
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Default RE: Nitro models pusher Bobcat?

You underestimate the power of the dark 4 stroke force
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Old 08-31-2006, 05:22 AM
  #268
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Default RE: Nitro models pusher Bobcat?

Oh come on now we all know that rubber bands are the untimate power souce.

As far as take down. I have a small puickup and I like to take three planes when I go to the field. Therefore I need to take the wings off so that I can fit them in my rack. I am going to keep the booms mounted to the wings and upgrade the canopee attachment little so that I can get at the wing bolts inside.

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Old 08-31-2006, 09:47 AM
  #269
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Default RE: Nitro models pusher Bobcat?

grrrr..... got disapointed again with its performance. Just not enough speed for satisfactory flying.

I only had a 12/6 pusher prop for the 65 4 stroke, and it flys as bad as the 46 with a 9/7.
I just bought a 11/8, and will try it soon.
Which prop would you use on this plane with a 4 stroke 65 ?




Its much easier with a jet engine......
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Old 08-31-2006, 10:36 AM
  #270
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Default RE: Nitro models pusher Bobcat?

I have an 11-7 three blade on mine. I haven't flown it yet so I can't tell you what it's gong to do. The chart says that @ 10,000 rpm a 7 pitch should be capable of 80 mph. You need a 9 pitch prop turning at 10,000 rpm to break 100 mph. With the Zinger props you have to get into a 12" prop before you can get into an 8 or a 10 pitch. Then you start to run into ground clearance issues.

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Old 08-31-2006, 11:06 AM
  #271
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Default RE: Nitro models pusher Bobcat?

well, i changed my mind.....I isnatalled a Magnum 65 GP 2 stroke.
This engine will hover my falcon trading cessna which weighs a ton, so it should move the bobcat.


Ill toss over the 4 stroke into the cessna instead.
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Old 08-31-2006, 05:09 PM
  #272
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Default RE: Nitro models pusher Bobcat?

Haha I had told you sonnich Move on to the .90 class !!
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Old 08-31-2006, 05:40 PM
  #273
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Default RE: Nitro models pusher Bobcat?

Zinger makes a 11X10 two blade. I would stay away from three blades unless you have to use them. They are not as good as a two blade. I have a rossi in mine. It will turn a 9x8 apc at 16000, but they don't have that in a pusher.
So i am going to run either a 9x7 zinger or a 10x6.

Now I have my saito 100 which should be a great match for the 11x10 zinger.

I would like to get a Dub Jett motor, but they are very expensive. the good thing is you can get them rev. rotation for $25 more and then you can choose any prop you want.


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Old 08-31-2006, 05:43 PM
  #274
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Default RE: Nitro models pusher Bobcat?

are zinger props of wood ?

I cant use wooden props on our grass field, as they get damaged too easy in this plane.
I only had wooden props, but they only last one flight.
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Old 08-31-2006, 06:15 PM
  #275
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Default RE: Nitro models pusher Bobcat?

I think you guy's should try the os 91fx, That should make you very happy.
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