Nitro models pusher Bobcat?
#953
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RE: Nitro models pusher Bobcat?
Here is mine all finished I have one of the new OS 55 AX two strokes in her and have a Graupner 11 x 8 prop..... Hope to maiden her when the weather improves here in the UK
Dennis
www.densplanes.co.uk
Dennis
www.densplanes.co.uk
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RE: Nitro models pusher Bobcat?
Looks good bigplumbs,....do you or any one else following this thread have any prior experience with the Graupner pusher props?....how do they compare with APC?
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RE: Nitro models pusher Bobcat?
Okay, I have to do some back peddling here regarding the fuel tank location. [sm=red_smile.gif] [sm=red_smile.gif]
I had posted this:
The stock fuel tank location (between the two bulkheads) is in front of the cg! I should have measured it before I shot my mouth off.....
Anyways the tank is now secure where it belongs. Only a couple more things to do until it is finished, then the long wait til springtime......
I had posted this:
Regardless of what the manual says, I am putting my fuel tank in the center section - close to the cg.
Anyways the tank is now secure where it belongs. Only a couple more things to do until it is finished, then the long wait til springtime......
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RE: Nitro models pusher Bobcat?
This plane flys perfect with the fuel tank in the location per the directions at 10.5" CG. Enjoy this plane, everyone at the field will.
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RE: Nitro models pusher Bobcat?
I got mine today. My buddy Scott and I started the build tonight. The only mod I wanted to do was adjust the main gear position. The gear are so far behind the cg, it makes rotation a little abrupt. All I did was to swap the mains side to side and flip them around. Drilled a hole in the rear of the gear block and presto, gear position moved forward about 3 inches. Could have moved it further forward by extending the groove in the block. We have a few ideas for the next one but I'm just going to fly this one as is. Going with the os50. Should be a hoot.
#958
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RE: Nitro models pusher Bobcat?
Randy,
Be advised that there is an extra block in the front of the landing gear block (on top inside the wing) that the original hole goes into. There may be a problem with the stability of the gear in the way you swapped it around. Also, I would add some additional glue to the stock blocks before I used them. When I took mine out to put in the retracts, there wasn't much in there...
Bob
Be advised that there is an extra block in the front of the landing gear block (on top inside the wing) that the original hole goes into. There may be a problem with the stability of the gear in the way you swapped it around. Also, I would add some additional glue to the stock blocks before I used them. When I took mine out to put in the retracts, there wasn't much in there...
Bob
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RE: Nitro models pusher Bobcat?
Looks good Bigplumbs. I'm working on one of these myself and have been following this thread as well as yours. There is one thing from your thread I'd like to point out though. While your rudder servo setup does indeed work with no mixing or reversing Y, the stock rudder servo locations will also work with no mixing or reversing Y. Hope the maiden goes well.
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RE: Nitro models pusher Bobcat?
this is my linx or a souped up bobcat. the other shot is the linx and my phoenix tigershark. the tigershark does 100+. haven't flown the bobcat yet.
#962
RE: Nitro models pusher Bobcat?
Mattgrant,
How did you get risd of the paint/dye in the canopy. Mine is coloured and I see yours is clear? I'm heavily modifying mine and red and green are not even on the spectrum of this. Redone in F4 pantome " JOLLY ROGERS" colors.
thank you
Dave
How did you get risd of the paint/dye in the canopy. Mine is coloured and I see yours is clear? I'm heavily modifying mine and red and green are not even on the spectrum of this. Redone in F4 pantome " JOLLY ROGERS" colors.
thank you
Dave
ORIGINAL: mattgrant
This plane flys perfect with the fuel tank in the location per the directions at 10.5" CG. Enjoy this plane, everyone at the field will.
This plane flys perfect with the fuel tank in the location per the directions at 10.5" CG. Enjoy this plane, everyone at the field will.
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RE: Nitro models pusher Bobcat?
FLYFRC:
I actually cut out the ugly smoke looking canopy and used it for a template. I then used clear plastic. I made the clear plastic about an 1/8" bigger so that I could glue it to the original canopy frame. Let me know if you would like more pictures.
I actually cut out the ugly smoke looking canopy and used it for a template. I then used clear plastic. I made the clear plastic about an 1/8" bigger so that I could glue it to the original canopy frame. Let me know if you would like more pictures.
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RE: Nitro models pusher Bobcat?
So for whatever reason, I decided to take off my engine and mount a dynamax fan on mine. I think I'll need to add a pound of lead in the nose since the engine/fan will sit at the rear and the pipe will extend and hang off the stab. I just finished the mount for it. I really don't know if this setup will be feasible with the addition of the counterweight and the thrust output gained. First test, I may not use any ducting. I'm still trying to work some issues out. We'll see.
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RE: Nitro models pusher Bobcat?
Well, I had some DF assemblies for sale so I decided to put one on.
Still thinking about thrust tube issues..
Anybody try this at home...
Test fit.
Still thinking about thrust tube issues..
Anybody try this at home...
Test fit.
#968
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RE: Nitro models pusher Bobcat?
DP
Have You thought about biting the bullet and moving the entire engine fan combination forward a foot or so. That would require major surgery but help with your CG issue and keep it from looking like the engine is falling off of the back.
I am curious to see how that will work with no intake ducting?
Anthony
Have You thought about biting the bullet and moving the entire engine fan combination forward a foot or so. That would require major surgery but help with your CG issue and keep it from looking like the engine is falling off of the back.
I am curious to see how that will work with no intake ducting?
Anthony
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RE: Nitro models pusher Bobcat?
Is that a Rossi engine? They were pretty heavy DF engines. If you have a 45 with a Turbax you may save some weight. A thrust tube is necessary as well as some rounding of the intakes if you want optimum performance. If you choose to stick with the setup pictured, you may want to rotate the head so the cooling fins point in the proper direction.
Mark M.
Mark M.
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RE: Nitro models pusher Bobcat?
Hey Guys,
No, I'm not too serious about doing a major conversion of this kit. Cutting up further up to mount the fan would definitely be a project and the installation of a thrust tube would be easier as well if you cut out half the fuse... and if this doesn't work out, I will convert it back to pusher prop.
I have the pipe isolated from the stab, there will be minimal vibration issues...
Actually the way I'm set up right now, a quick hand check and I'm only out to 11.5"ish balance point so a little lead up front and I should be good.
What I'll do is run some static ground tests to check the thrust output sans ducting and then I've got some FG ducting ready to install but yes, it won't look pretty hanging off the back...
Heck it just for fun anyway, flew the bageesus out of it with the pusher prop - my bobcat has more miles on it than a las vegas stripper....
No, I'm not too serious about doing a major conversion of this kit. Cutting up further up to mount the fan would definitely be a project and the installation of a thrust tube would be easier as well if you cut out half the fuse... and if this doesn't work out, I will convert it back to pusher prop.
I have the pipe isolated from the stab, there will be minimal vibration issues...
Actually the way I'm set up right now, a quick hand check and I'm only out to 11.5"ish balance point so a little lead up front and I should be good.
What I'll do is run some static ground tests to check the thrust output sans ducting and then I've got some FG ducting ready to install but yes, it won't look pretty hanging off the back...
Heck it just for fun anyway, flew the bageesus out of it with the pusher prop - my bobcat has more miles on it than a las vegas stripper....
#972
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RE: Nitro models pusher Bobcat?
Thanks Bob for the pictures and directions for installing the retracts as I finally got up the nerve to cut the wings and started working on mine . They were easy to follow and the pictures helped tremendously. They made the job a lot easier than I thought. At least so far anyway.
I now have both wing plates cut and the holes cut in both wings for those plates. The next step is cutting the the sub-ribs to reinforce the plates. Then onto the nose gear. Don't know if you did yours yet but if you did I would to know if it is possible to see how you did it.
Thanks again.
Bill
I now have both wing plates cut and the holes cut in both wings for those plates. The next step is cutting the the sub-ribs to reinforce the plates. Then onto the nose gear. Don't know if you did yours yet but if you did I would to know if it is possible to see how you did it.
Thanks again.
Bill
ORIGINAL: rhklenke
OK, so here we go with the installation of the SpringAir 305 retracts in the Bobcat...
First, we make a 1/4" ply mount to bolt the retracts to. It needs to be large enough to provide adequate area to spread the loads out and attach to the underlying structure (which we will reinforce).
Then we decide where to put the units in the wing. I decided to put them further outboard than the stock gear. I want to make the gear legs as close to as long as the stock units as possible. Even this far out, the wheels will be partially inside the fuselage when they are retracted...
Mark the location of the plates on the lower wing skin, and slice into your new airplane...
More to come...
Bob
OK, so here we go with the installation of the SpringAir 305 retracts in the Bobcat...
First, we make a 1/4" ply mount to bolt the retracts to. It needs to be large enough to provide adequate area to spread the loads out and attach to the underlying structure (which we will reinforce).
Then we decide where to put the units in the wing. I decided to put them further outboard than the stock gear. I want to make the gear legs as close to as long as the stock units as possible. Even this far out, the wheels will be partially inside the fuselage when they are retracted...
Mark the location of the plates on the lower wing skin, and slice into your new airplane...
More to come...
Bob
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RE: Nitro models pusher Bobcat?
hi guys
i have one of these bobcats as i got it for christmas, after seeing it at a model show last july, i think it came to the uk market sometime after the american market.
just adding my thoughts, comments on the plane so far, it is 75% built maybe of some use to some of you.
i have experienced many of the same problems as mentioned in this thread ie.
loose material of the blue coverings of the wings.
shortage of bolts form the hardware pack
also lack of length of some of them
i am building mine with the wings glued in to position and using the tail section as removable to help with transportation, leaving colour coded plugs
poking out the holes in the wings to conect the four servos in the tail section
i am also using the JEN57 engine, which i dont think anyone else has mentioned yet, it is supposed to be as powerful as most 61's but only weighs the same as an average 40. this is the engine recommended to me by the uk importers (planenutz) to spin an 11x7 prop
radio setup and kit is
futaba s148's in the ailerons and also for the throttle and nose wheel
and the same mini servos as planenutz use in the tail section
receiver setup is as follow futaba R138DP PCM1024
CH1 aileron 1 - flaperons mix
CH2 elevator 1 - prog mix 1 master
CH3 throttle
CH4 rudders on a Y lead (straight not reversed) - prog mix 2 master
CH5 battery input and monitor
CH6 aileron 2 - flaperons mix
CH7 elevator 2 - prog mix 1 slave
CH8 nosewheel - prog mix 2 slave
all programmed with a FF9 this allows me seperate trim and servo movement for the nosewheel, each aileron and helps with fine adjusting the elevator servos together
please feel free to comment on my setup as i always like advice from others, i bought this plane as a maybe into the world of turbines after i had flown with the glow engine and after following this thread and seeing that it is possible to have retracts and a turbine, then maybe one day !!
thanks
steve
i have one of these bobcats as i got it for christmas, after seeing it at a model show last july, i think it came to the uk market sometime after the american market.
just adding my thoughts, comments on the plane so far, it is 75% built maybe of some use to some of you.
i have experienced many of the same problems as mentioned in this thread ie.
loose material of the blue coverings of the wings.
shortage of bolts form the hardware pack
also lack of length of some of them
i am building mine with the wings glued in to position and using the tail section as removable to help with transportation, leaving colour coded plugs
poking out the holes in the wings to conect the four servos in the tail section
i am also using the JEN57 engine, which i dont think anyone else has mentioned yet, it is supposed to be as powerful as most 61's but only weighs the same as an average 40. this is the engine recommended to me by the uk importers (planenutz) to spin an 11x7 prop
radio setup and kit is
futaba s148's in the ailerons and also for the throttle and nose wheel
and the same mini servos as planenutz use in the tail section
receiver setup is as follow futaba R138DP PCM1024
CH1 aileron 1 - flaperons mix
CH2 elevator 1 - prog mix 1 master
CH3 throttle
CH4 rudders on a Y lead (straight not reversed) - prog mix 2 master
CH5 battery input and monitor
CH6 aileron 2 - flaperons mix
CH7 elevator 2 - prog mix 1 slave
CH8 nosewheel - prog mix 2 slave
all programmed with a FF9 this allows me seperate trim and servo movement for the nosewheel, each aileron and helps with fine adjusting the elevator servos together
please feel free to comment on my setup as i always like advice from others, i bought this plane as a maybe into the world of turbines after i had flown with the glow engine and after following this thread and seeing that it is possible to have retracts and a turbine, then maybe one day !!
thanks
steve
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RE: Nitro models pusher Bobcat?
In checking engine clearance, when I placed the two shaped yellow engine mount blocks on the airplane, I found out my engine (Rossi 60) won't clear. I'm going to have to put two 1/4" spacers under those block to get minimal clearance. Anybody else have this problem? Also, in adding the spacers, I'm hoping I don't have a fuel draw problem. Will have to see how high I can go with the tank. Any experiances anybody has had with this problem, I'd be interested in hearing how you rectified the situation. Thanks Joe
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RE: Nitro models pusher Bobcat?
I had a space problem below my 55ax. I just used a dremel drum sanding bit and ground out enough material to allow the engine to fit, then sealed the trimmed area with CA. Worked fine.
ORIGINAL: JL636
In checking engine clearance, when I placed the two shaped yellow engine mount blocks on the airplane, I found out my engine (Rossi 60) won't clear. I'm going to have to put two 1/4" spacers under those block to get minimal clearance. Anybody else have this problem? Also, in adding the spacers, I'm hoping I don't have a fuel draw problem. Will have to see how high I can go with the tank. Any experiances anybody has had with this problem, I'd be interested in hearing how you rectified the situation. Thanks Joe
In checking engine clearance, when I placed the two shaped yellow engine mount blocks on the airplane, I found out my engine (Rossi 60) won't clear. I'm going to have to put two 1/4" spacers under those block to get minimal clearance. Anybody else have this problem? Also, in adding the spacers, I'm hoping I don't have a fuel draw problem. Will have to see how high I can go with the tank. Any experiances anybody has had with this problem, I'd be interested in hearing how you rectified the situation. Thanks Joe