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-   -   Nitro models pusher Bobcat? (http://www.rcuniverse.com/forum/rc-jets-120/4588799-nitro-models-pusher-bobcat.html)

opjose 05-23-2012 04:25 PM

RE: Nitro models pusher Bobcat?
 

Quote:

ORIGINAL: comstech

Ok not sure if this will help the opening on mine is 13 in (333mm) long x 3 1/4 (80mm) in the centre wide and I do have an 8mm lip all the way round. So I will email BVM Jets to see if I can get the size from them

Else anyone else go any idea's as $30 + postage is going to hurt

Do have a Nitroplanes/Nitromodels Bobcat?

That is what this thread is about.

The ParkFlyer plastic canopies should fit. I've used them.


Turbulence 05-23-2012 08:40 PM

RE: Nitro models pusher Bobcat?
 
For the Bobcat 50? I ordered one from the gentlemen in the UK and it arrived last week. Nice straight replacement, just takes a bit longer to cross the pond into the USA. It was about the same though $32.48USD

His email is pisces.baits@googlemail.com his Name is Stephen Davis


Ralph

Quote:

ORIGINAL: comstech

Just a reminder to everyone that I am seeking a canopy for a bobcat - I don't care about condition

comstech 05-23-2012 08:54 PM

RE: Nitro models pusher Bobcat?
 
<font size="3">Hi <span class="subhead">opjose, I believe it is. I did not get it new but all the pics match. You tell me does the cockpit opening match yours?
</span></font>13 in (333mm) long x 3  1/4 (80mm) in the centre wide and I do have an 8mm lip all the way round
<font size="3"><span class="subhead"><br type="_moz"/></span></font>

bob092 05-24-2012 02:58 AM

RE: Nitro models pusher Bobcat?
 
I havent responded to this post in quite a while. A good source for Nitro planes bobcat 50 is directly through Nitro Planes. They have helped me get quite a few parts that I have needed . i always go to the vendor that sells the plane...they make a few bucks but will get you what is needed and it is the correct part...no second guessing or worrying will they take it back if wrong.
Bob

opjose 05-24-2012 09:51 AM

RE: Nitro models pusher Bobcat?
 
Quote:

ORIGINAL: comstech

<font size=''3''>Hi <span class=''subhead''>opjose, I believe it is. I did not get it new but all the pics match. You tell me does the cockpit opening match yours?
</span></font>13 in (333mm) long x 3 1/4 (80mm) in the centre wide and I do have an 8mm lip all the way round
<font size=''3''><span class=''subhead''><br type=''_moz''/></span></font>
How about some pictures if you could?

That may help identify the plane.

Papa51 05-24-2012 12:42 PM

RE: Nitro models pusher Bobcat?
 
Has anyone out there converted the Bobcat 50 horizontal stab into a fully symmetrical airfoil? It really wouldn't be that difficult. It might help with some of the dynamic trim/balance problems I've been reading about. I'm considering building one for my Bobcat. You could also just add some small curved half-ribs to the bottom of the stock stab and then monokote over them. It could be done at a very small weight penalty and as a bonus it would give some extra thickness to better hide a single, stab-mounted elevator servo. Any thoughts from you gurus out there?

SECRET AGENT 05-24-2012 04:59 PM

RE: Nitro models pusher Bobcat?
 
1 Attachment(s)
opjose,

Mine is the Bobcat-52 from Nitromodels/Nitroplanes.

I would definately buy one directly from them but they have been out of stock for at least 6 months. I contacted them directly and they told me to just keep watching the website. After 6 months of watching the website I am giving up on them.

My opening is the same: 13 in (333mm) long x 3 1/4 (80mm) in the centre wide and I do have an 8mm lip all the way round

opjose 05-24-2012 08:36 PM

RE: Nitro models pusher Bobcat?
 
The Park Flyer Plastics canopy should fit that.

They have more than one canopy.

Give them a call, they have modified canopies for other people to fit their planes.

SECRET AGENT 05-25-2012 12:17 PM

RE: Nitro models pusher Bobcat?
 
Thanks opjose, I'll give them a call.

Papa51 07-16-2012 11:05 AM

RE: Nitro models pusher Bobcat?
 
Opjose,

I just recently acquired a Bobcat 52 N.I.B. off the RCU classifieds. I'm planning on going with OS .75AX, 11 x 8P Graupner, retracts the whole 9 yards. i'm looking for some advice on engine location (forward/aft). I know that the farther forward the engine sits on the mount, the closer the propeller tips come to the wing trailing edge. Is there an optimum or minimum clearance I should maintain between the prop tips and the wing trailing edge? I could just mount the engine as far aft as possible but I know there is a CG issue to be addressed with larger engines on this airframe. This .75AX is pretty hefty (26 oz.). I want to leave enough clearance without having the engine unnecessarily too far to the rear. I've read through this entire thread twice and there is a wealth of knowledge and experience here that will enable me to be successful with this aircraft. I tried to get an idea by looking at all the photos in this thread but it is kind of hard to extrapolate a measurement from a picture. It will certainly eliminate what would normally be a lot of trial and error getting this aircraft set up correctly and flyable. Any input from any of you still following this thread will certainly be helpful and appreciated.

opjose 07-16-2012 12:34 PM

RE: Nitro models pusher Bobcat?
 

Quote:

ORIGINAL: Papa51

Opjose,

I just recently acquired a Bobcat 52 N.I.B. off the RCU classifieds. I'm planning on going with OS .75AX, 11 x 8P Graupner, retracts the whole 9 yards. i'm looking for some advice on engine location (forward/aft). I know that the farther forward the engine sits on the mount, the closer the propeller tips come to the wing trailing edge. Is there an optimum or minimum clearance I should maintain between the prop tips and the wing trailing edge? I could just mount the engine as far aft as possible but I know there is a CG issue to be addressed with larger engines on this airframe. This .75AX is pretty hefty (26 oz.). I want to leave enough clearance without having the engine unnecessarily too far to the rear. I've read through this entire thread twice and there is a wealth of knowledge and experience here that will enable me to be successful with this aircraft. I tried to get an idea by looking at all the photos in this thread but it is kind of hard to extrapolate a measurement from a picture. It will certainly eliminate what would normally be a lot of trial and error getting this aircraft set up correctly and flyable. Any input from any of you still following this thread will certainly be helpful and appreciated.
Since the engine is mounted backwards we'll talk about forward-backward relative to the whole plane.

As long as the prop clears the wing trailing edge by about 1/4" or more you should be fine. I would recommend 1/2" clearance just for safety purposes.

I find that with the 75 size engines, 1/2" forward or backward does NOT have a dramatic effect on the C.G.... and whatever there is can be fixed by moving the battery packs a bit.

I put my dual packs in the nose.

Remember that this plane will not fly like other prop planes you may own. Some points...


- It will seem to be "mushy" until it gets up to speed.

- If the wing incidence is not positive when the plane is sitting on the ground it will seem to stick to the ground until it has more than enough airspeed, then head straight up, loosing speed and control.

- Elevator "neutral" should exhibit a slight upward deflection.

- Slight aileron reflex helps your landings. Put this on a switch if you can and turn on the reflex when entering final. ( Practice high in the air IMMEDIATELY once the plane is trimmed... )

- Landings should occur slightly nose high, once the main gear touches down, try to keep the nose gear up to bleed off speed.

- You'll need lots of runway.




Papa51 07-17-2012 09:00 AM

RE: Nitro models pusher Bobcat?
 
1 Attachment(s)

Thanks opjose.

Once I recieve all the parts and pieces I need for construction I plan to do a mock-up so that I know what I'm up against CG wise. That way I can make adjustments during the building/assembly process to assure I don't run into any major CG problems. I plan on going with Springair 302 or 305 rectracts and the landing gear shown. Elevator (HS-125MG), Rudders (HS-82MG), Ailerons (Futaba 3152's),
16oz. tank stopper forward. Can I get away with a micro servo on the retract air valve? For whomever is still following this thread, I welcome any comments from the peanut gallery out there. Give me your experiences (good/bad/indifferent).

opjose 07-17-2012 09:05 AM

RE: Nitro models pusher Bobcat?
 

Quote:

ORIGINAL: Papa51


Thanks opjose.

Once I recieve all the parts and pieces I need for construction I plan to do a mock-up so that I know what I'm up against CG wise. That way I can make adjustments during the building/assembly process to assure I don't run into any major CG problems. I plan on going with Springair 302 or 305 rectracts and the landing gear shown. Elevator (HS-125MG), Rudders (HS-82MG), Ailerons (Futaba 3152's),
16oz. tank stopper forward. Can I get away with a micro servo on the retract air valve? For whomever is still following this thread, I welcome any comments from the peanut gallery out there. Give me your experiences (good/bad/indifferent).
The problem with most Micro servos is that they strip too easily.

Consider something a bit larger but not as large as a Mini.

I've used some very strong 15g ( weight ) servos from HK that serve me well for this purpose. They are only slightly larger than the Micros.


comstech 07-17-2012 03:35 PM

RE: Nitro models pusher Bobcat?
 
Can you post a picture when you have the tank mounted as there is not much room with the small metal wing alignment bar in place

Timthetoolman1 12-09-2012 06:49 PM

RE: Nitro models pusher Bobcat?
 
Did anyone find a canopy that fits right? I'm making one now but it would be easier if someone else already makes one.

Dauntae 12-10-2012 12:21 AM

RE: Nitro models pusher Bobcat?
 
I got lucky a ways back and managed to get one from nitro models on one of the RARE ocations they had them but kind of got out of flying for a while and have yet to trim and install it, Thinking of making a plaster mold to make a few more to keep in reserve but that will be a ways off. In the middle of trying to buy a house and have a lot of stuff packed away but if I ever get to it I'll try and make a bunch and maybe put a few here for those in need.

Timthetoolman1 12-10-2012 12:32 AM

RE: Nitro models pusher Bobcat?
 
That's what I'll be doing with them if there is not a replacement. I've got the plaster replacement made and have access to a production size vacuum table. I just wanted to see if there is one that fits already.

Dauntae 12-10-2012 01:09 AM

RE: Nitro models pusher Bobcat?
 
When I was trying to find one when I got lucky at Nitro models I searched and none where to be had, Hopefully someone found a sorce since then. It seems like the canopy is the first thing to get damaged on these, Mine broke in transport to from the field.

Dauntae

BaldEagel 12-10-2012 02:23 AM

RE: Nitro models pusher Bobcat?
 
noray makes a very good replacement for the Falcon 120 may possibly fit, look him up under members.

Mike

BillS 05-04-2013 09:46 AM

RE: Nitro models pusher Bobcat?
 
Quote:

ORIGINAL: Papa51

Opjose,

I just recently acquired a Bobcat 52 N.I.B. off the RCU classifieds. I'm planning on going with OS .75AX, 11 x 8P Graupner, retracts the whole 9 yards. i'm looking for some advice on engine location (forward/aft). I know that the farther forward the engine sits on the mount, the closer the propeller tips come to the wing trailing edge. Is there an optimum or minimum clearance I should maintain between the prop tips and the wing trailing edge? I could just mount the engine as far aft as possible but I know there is a CG issue to be addressed with larger engines on this airframe. This .75AX is pretty hefty (26 oz.). I want to leave enough clearance without having the engine unnecessarily too far to the rear. I've read through this entire thread twice and there is a wealth of knowledge and experience here that will enable me to be successful with this aircraft. I tried to get an idea by looking at all the photos in this thread but it is kind of hard to extrapolate a measurement from a picture. It will certainly eliminate what would normally be a lot of trial and error getting this aircraft set up correctly and flyable. Any input from any of you still following this thread will certainly be helpful and appreciated.
In 2009 after having 3 other engines on a Bobcat I put a Tower .75 on the airplane. I put 10 flights on the Bobcat with the Tower .75. There were several mid range dead sticks and engine idle was 3500 rpm and much too fast for landing. I simply was unable to achieve top speed and idle speed with props that could be used.

I stopped and bench tested for 4 days (about 2 hours per day with various pusher and tractor props) with engine in the airplane. The engine could be adjusted and would run perfect with tractor props. All pusher props did not appear to cool properly and either did not transition properly or would not idle below 3500.

I stopped and removed the engine. Your success will be better.

Bill

SU-31 flyer 05-04-2013 01:42 PM

RE: Nitro models pusher Bobcat?
 
I have a OS 60FX in mine and think it is about right. Fly well and lands great. I did put my tank in with the front ot the front of plane to help fuel draw.

Dauntae 05-04-2013 03:01 PM

RE: Nitro models pusher Bobcat?
 
I have a Webra Speed .60 on mine, Only had one flight with that engine and life started getting in the way so stopped flying for a while but getting back into it now. If I remember right that Webra was getting in the 13 or 14K mark for rpm with a 11x7 but those Webra's were made for rpm. Went like a bat out of hell with that engine and now I got to get my thumbs back before I attempt to try flying the Bobcat again but I'll get there.

Dauntae

DP 11-09-2014 05:20 AM

I don't know if anyone is still watching this thread but I I have a question. I have a Bobcat 50 and I want to put an electric motor with prop on it. Would like to see at least 125 to 130 out of it. Anyone done this or have an idea of what setup to use.

Papa51 11-09-2014 06:59 AM

DP,

You're probably not going to get that kind of performance out of an electric pusher setup with just a propeller. Electric Ducted Fan (EDF) would be the way to go for those speeds.
Check out the electric threads. Good luck with it.

DP 11-09-2014 12:53 PM

Thanks for the reply papa51. I will check that out.


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