RE: Nitro models pusher Bobcat?
 

Wow, and I thought my .76 equipped Bobcat .52 landed "hot"...

I can imagine that yours screams in for a landing! Very NICE!

Did you try adding up 1/4" up aileron as "flaps" to slow it down?

When combined with a bit of down elevator, this works fairly well for me. It took 3 flights for me to get the settings right though.

I'm going to try "dirtying" up the surfaces via mixing, to brake it once on the ground....

RE: Nitro models pusher Bobcat?
 

my wheel brakes will be here in a day or two. that sould stop it

RE: Nitro models pusher Bobcat?
 

Just wondered if anyone has tried using a Super Tiger G90. I have one lying around that was converted to gas by BME. I'm thinking of converting it back to glow for this airplane. I don't want the extra weight of ignition and second battery. I also have an OS 50-SX lying around. Which one should I use?
Thanks

RE: Nitro models pusher Bobcat?
 

Just wondered if anyone has tried using a Super Tiger G90. I have one lying around that was converted to gas by BME. I'm thinking of converting it back to glow for this airplane. I don't want the extra weight of ignition and second battery. I also have an OS 50-SX lying around. Which one should I use?
Thanks

RE: Nitro models pusher Bobcat?
 

My GMS .76 has a higher stated ( if you can believe the vendors! ) bHP rating than the ST G.90.

I'm running it with the rather small 11x7P prop, so you should be fine.

You will need to redo the engine mount blocks, but this is not a big problem.

Also note that deep under the fiberglass, is a VERY hard wooden mounting base ( NP did this right ), so as long as you use washers or larger blind nuts you should not have a problem.

You may need to add a larger battery pack to the plane at the nose to offset the weight of the motor.

I'd imagine that a 1800 to 2400mAh 6v pack will more than do the job.

The SuperTigre muffler is fairly blunt on the tail end ( which will end up facing forward ) so this will add a good bit of drag.

RE: Nitro models pusher Bobcat?
 

This worked so well for me that it's amazing.

The plane ( and ME! ) now stay clean.

I didn't need any special silicon tubing, A muffler extension as you pictured, worked perfectly.

I cut the holes and CA'd the entire area in the wing from the opposite holes, to add strength.

I epoxied a metal grommet ring ( used to grommet sail cloth ) with a bit of coaming on the top and bottom.

After installing the muffler and extension I used canopy glue on the extension to seal the wing opening and prevent any accidental leakage of fuel into the wing.

If anything my engine seems to be running a bit faster now and my plane is carving BIG arcs in the sky.

At the field I've had several people marvel at how ingenious this is.

RE: Nitro models pusher Bobcat?
 

Thanks, after finally finishing the whole thread, I think I might just put the 50-SX in it and get the Robart retracts. It seems like the bigger engines don't work too well with the available pusher props. I think eliminating the drag will give me more speed than the bigger heavier ST G90 with fixed gear. Hopefully Tower with have the 520W1's back in stock soon.

RE: Nitro models pusher Bobcat?
 

Hi guys - quick update - I ordered the Weston pipe for my OS 55 AX, and I spoke with Dub at Jett Engineering....he actually modified a pipe for me, but putting the stinger so the exhaust exits out the back, so I paid for that too. He tested with my motor and several different props, and saw 1500-1800 increase in RPMs. This is with his Red tuned muffler. There's some guys at my field with the Cermark F16, and have Jett motors and pipes on them, and they scream.

So the goods should be here this week, and I'll let you know about my tests flights.

I also finally bought Real Flight G3.5, and it came with the #5 addons, which includes the BVM King Cat. GOOD simulation, as I think mine flies the same way - except that the jet power moves the plane faster, and because of the extra weight makes it a challenge to land. Now I need to figure out how to hook up my Spektrum, and make it work the way my real one does (I have the heli version of the radio because I fly both, and hate the ratchet on the throttle - but the retract switch is in a totally different place than the airplane version). Any help on this would be appreciated... ;) I will also comment about Turbine power....if this simulation is as real as everyone says it is, I think I'll stick to EDF and IC power for now. The turbine sounds KILLER, and has great power, but I'm not sure if I can yet justify the money and wing loading trade off for it. Also, I think that if I'm going to use the sim a lot, that I need to take it seriously, and not like a game. It's very easy to hit the little red button, and I'd hate for that to transfer to a real model... All in all, it's COOL though, as I'm able to practice the crazy stuff without spending money for repairs!

* * *
HAL - Did you fly it yet?
* * *
Al - Did you pick up a new one yet?
* * *
Jack - what about the Bobcat Turbine?

See you guys soon!
Mark

RE: Nitro models pusher Bobcat?
 

GMAIR - I agree with you. This is what I'm doing. Keep the weight down - you should be able to locate everything in the fuse that you don't have to add any weight. I'm using the stock Robart air can that comes in the air kit, and that's up front. The battery (Venom 6v 1800, I think) is also as far forward as it can go.

The OS 55AX on it's first gallon (15%) flew fine. I then switched to 30% heli fuel, and NICE improvement in performance...now I've ordered 2 different pipes to play around with - but I agree with you - the extra weight of the .75 and extra horsies is a waste if you can't prop it right. Let me know how it goes.

Thanks,
Mark

RE: Nitro models pusher Bobcat?
 

PM me with your e-mail address and I'll send you a Bobcat variant for the Kingcat.

What is fairly neat is that you can also experiment with using the control surfaces for increased braking, etc. w/o every doing this on your actual plane.

I verified the suggested 1/4" up flap settings in G3 before ever trying them out on the Bobcat.

RE: Nitro models pusher Bobcat?
 

Nice opjose - thanks. Here's my email: [email protected] - I can't possibly receive any more spam than I already do! :)

I found it really tough to land any of the stock jets, and keep them on the runway...I'm (hoping) that this me needing practice getting used to the sim...but I can do touch and go's all day long with any of the prop planes, and never run out of runway. I was very amazed when I checked out the slope soaring with the Minstral glider - fast as the jets! I have always wanted to try that for real, but in Florida, the tallest mountains we have are the landfills! :)

Are you using your Spektrum with RF? I haven't plugged mine in yet, but tonight.

Thanks,
Mark

RE: Nitro models pusher Bobcat?
 

Hi guys,
DUB from JETT ENGINEERING IS COOL!
Look what he made for me! He took the normal rear-exhaust pipe, filled the hole, then put the stinger facing the rear. I will give you test results (RPM's) as soon as I run it.

With the stock muffler, using 30% Heli fuel, APC 11x7 prop, I'm turning around 13,200 on the ground....I will run the same setup, but just change the pipe to the new pipe, and fly it, and let you know what happens. They guys at Jett think I should be using a smaller prop to get around 15K...so I'll see if I can find any smaller pusher props (10x6, 10x7, or 11x6) I just don't know if I can find any.

So I'm anxious to get back out to the field! It may have to wait until Thursday unfortunately, but I'll run the motor tomorrow after work just to see what it does.

OPJOSE - send me the Bobcat file for Real Flight! [email protected] Thanks, man.


CYA!
Mark

RE: Nitro models pusher Bobcat?
 

Check your mail.

RE: Nitro models pusher Bobcat?
 

Was on Nitroplanes website today and the show the Bobcat 50 with an option of retract ready for $5.00 more. Anyone have one of these yet? Some pictures would be nice of it.

RE: Nitro models pusher Bobcat?
 

Hmmm...

http://image2.rcuniverse.com/gallery...5/lg-99541.jpg
http://image2.rcuniverse.com/gallery...5/lg-99537.jpg
http://image2.rcuniverse.com/gallery...5/lg-99534.jpg
http://image2.rcuniverse.com/gallery...5/lg-99535.jpg
http://image2.rcuniverse.com/gallery...5/lg-99536.jpg

RE: Nitro models pusher Bobcat?
 

OPJose - thanks - got it installed after a couple of minutes on Google... :)

The plane flies pretty realistic, although I think you have things a bit more sensitive than mine (ailerons).

So how do we program in a bit of spoilerons? I want to try Terry's suggestion and see how that affects the plane.

The 75 seems more powerful on takeoff, but not really faster than my .55 setup (only a little). Interesting. I have the new pipe on (see the picture?) and I'm going to try and scoot out of work early today to fly it.

TTYL
Mark

RE: Nitro models pusher Bobcat?
 

Re: Sensitive

The roll rates mimic what I have on my plane. It's quite quick on the rolls, and it tends to surprise everyone at our field when I hit full deflection... I get a lot of "WOW!"'s.

Re: Spoileron.

That's aready there.

Turn the knob to the right and the "spoilerons" ( actually it's an "inverted flap" ) come up.

I have the knob set to raise them the same amount I have on my plane.

Re: Takeoff

Yup...

For some reason G3 seems to accelerate the planes far too quickly on runup. I typically lower throttle response time to make takeoffs a bit slower.

Speedwise the model is close to what I've been observing at the field.


Remember that the .55 does pretty well on this plane.

The .75's and .76's are effectively UNDER PROPPED with the 11x7's and 11x8's so maximum HP is not being attained, whereas with the .55 you are in the ball part. The .55 ends up in it's optimal rpm range.

RE: Nitro models pusher Bobcat?
 

[img]jettpipe.jpg[/img]

Here's the pipe.

RE: Nitro models pusher Bobcat?
 

Cool - I'll try it when I get home...

Hopefully I'll get out of here early enough to go fly...if not, well, I'm Jewish, so I'm off tomorrow...but I'm not very religous, and definitely not going to temple. :)

RE: Nitro models pusher Bobcat?
 

MARKTUR
I am fying the same setup you have but with an ultrathrust muffler .You will find that the best prop for the
os 55 on this plane is the 11x7apc .I have tried all of them . The hot pipe will bring you about another 1500 rpm, better vertical performance, and almost double your fuel consumption .I am out of fuel in 5 minutes.

RE: Nitro models pusher Bobcat?
 

Nice mod to the jetstream. What did that cost?
thanks

RE: Nitro models pusher Bobcat?
 

Is that with the default tank?

Wow...

RE: Nitro models pusher Bobcat?
 

Timevac - I paid $75 for the pipe...this doesn't mean it's his final price - he built it for me after a couple of emails back and forth. But definitely call him or email him and let him know he should produce them.

I have the Weston pipe on it's way, too.

I can't believe what you're saying about the fuel consumption....wow....I land after 5 minutes or so with a bunch of fuel left now...I guess I'll set the timer for 5 minutes and then check it. I don't fly with the throttle wide open continuously, though. I'm sure flying styly also affects things. What fuel are you using?

I'll probably take it out around lunchtime today...

Cya
Mark

RE: Nitro models pusher Bobcat?
 

Yeah... I got about 6 minutes at WOT initially but I had my engine seriously out of tune at the time.

It was spitting out much more fuel than it was consuming...

Once the engine was broken in I've been getting about 15-17 minutes to tank empty at WOT ( I upgraded it slightly to a full dubro 12oz tank I really need a 14oz tank in it though.. ).

I have my timer now set to 14 minutes for safety as you DO tend to fly this plane as fast as you can...

5 minutes is far too much consumption for the O.S. .55.

It should eat up no more than .7oz/minute at Wide Open Throttle.

RE: Nitro models pusher Bobcat?
 

The first flight on my Bobcat, the carb got a little burr in it and the throttle was stuck at WOT and I think I flew about 10 minutes before it finally ran out of fuel. That is with the stock tank and the Tower 75.