[quote]ORIGINAL: Wayne22

The only damage was a slightly bent main gear leg.... Easily bent back at the field (too easily, perhaps....) Noticed a heck of a nose down pitch when the engine quit, though....

Second flight went much better, but still getting a nose down pitch when coming off the power...and running out of up elevator.

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Hi Wayne!
So Now you know what I have been going on about and It like all aircraft need a few changes to get It the way you want it to fly
I replaced the Nose and main U/C legs before I even test flew mine as I have had experience with another of that manufactures models. Yes I still have the standard landing gear blocks on mine also after a heap of flights

What I do to get rid of the nose down thing is to have a flight condition set up for landing , As I slow it down and turn onto base leg I bring the ailerons UP about 3/16 -- 1/4 of an inch.. This has the effect of giving it Up elevator trim as It acts like a delta, and you can slow It down for the final approach with a nose High rear wheels first landing . Try It you will be pleased .

Noise has been a problem but after trying a few muffler set ups I ended up with the set up that you can see in the Pic of a previous post of mine . Prop noise Is now the main Issue but I do not think that there Is much I can do about that .


G .

What an excellent idea!!!!! Other than mounting the elevator servo in the stab, I didn't make any structural changes, so it is pretty much stock.... I didn't want too much time and effort invested in it, til I got a feel for how it flies........ Now, on to chapter two!!!!

well I think I'm done adjusting my bobcat. In the first photo you can see I added a 1/8" shim on the tail boom and wing and the second photo you can see the elevator is straight with the stab after a flight. my cg is at 9 7/8" and now this planes glides down real smooth and will fly inverted real nice. will have a vid when I can get someone to take it for me. I'm not saying this settup will work for all but it works for me and I'm a happy camper now

I own a tower 75 and use it on my Keecat 65. When I was breaking the engine in, it just did not want to run properly and no one could tune it. So, one day, I just decided to take a couple of turns out of the low speed needle and sure enough, that fixed the problem immediately. It runs absolutely perfectly now and I think its a great engine for the little money you have to dish out.

Wayne,
Congrats on the maiden. Where is your CG set at? AGR413 mentioned something earlier about the nose diving problem when power was cut with his CG more than 10.5" but went away when the CG was moved forward to around 10.25".

Thanks, it is right on 10.5 inches... one of the theories my son and I were bouncing around was to move it back even more because the elevator is not very responsive. I think it is that flat bottom stab causing the inconsistencies, but it seems to be doing the opposite of what aerodynamic theory tells us........

I have to move the engine back a bit...I never accounted for the swept back trailing edge, and the first prop (a bit flexible) smacked the trailing edge. I put the apc on which is a lot stiffer, and it cleared the trailing edge, but not by much.....

Quick question, if I use the stock servo locations, what length servo extentions does this kit need. I'm thinking like 18" or 24" maybe for Elevator, Rudder and maybe Aileron too. I'm traveling this week and would like to purchase what I need this week, so I can build this weekend.

Thanks,

Lee

Lee,

Don't cut yourself short...Extentions can't be lengthened if you know what I mean....get the 36'' for the tail section...I used 18'' in the wings and it worked out....good luck and don't forget to strengthen the the landing mains blocks.......Mark

I flew mine on the weekend (ASP (Magnum) 52 with 10x7 prop) and it flew about how I figured it would except...

On takeoff (after lifting off) it wants to climb very steeply, needing about 1/3 down elevator to stop it going vertical. This isn't the "leap off the deck syndrome).

The faster it flies (at full throttle) the more it wants to tuck it's nose down though. If I do a high-speed run I have to use increasing back-pressure on the stick to keep it level -- but once it slows down it starts to climb agressively again.

I'm wondering if it's that lifting tail section providing an increasing amount of lift (thus pitching the nose down) as the airspeed goes up.

Right now it's quite manageable but not a characteristic I enjoy. My CG is about 10.25 inches and it needs a good dose of down elevator to stay straight and level when inverted (indicating to me that the CG could/should go back further).

Did anyone else use the straight piece of wire when fitting the wing? The instructions on mine made no mention of this wire and although the position of the holes for it were marked on the fuselage they were not drilled. I drilled them and fitted the wire because I wanted to have the option of removing the wings rather than gluing them on -- although I'm reconsidering that.

I switched to a 10x8 prop today and noticed absolutely no difference in performance. The RPMs dropped slightly but the speed was identical.

The ASP is pulling (by ear) about 14,000-14,500RPMs with the 10x7 and I'm going to fit an OPS pipe. That ought to liven it up a bit :-)

What I am impressed with is the weight -- it's really light and you can slow it *right* up on the approach for very nose-high touchdowns. However, I've noticed that the elevator isn't too powerful in the turns -- another indicator that perhaps the CG is a little too far forward for my liking.

Just a few more data points.

I think your thrust line is off. The engine mounting block on this plane is soft and you can change the thrust angle by simply tightening the screws more in the front or the back.

Update, if you are flying the Tower .75 with a pitts muffler don't bother trying the 11x8 zinger pusher, it is terrible. The 12x6 zinger pusher performs much better.

If you secure the receiver just behind the nose gear block you'll need 36" extensions for the tail servos and 24" for the ailerons. I used bulk servo wire and cut and soldered my own.

Wayne,
That's the exact scenario that AGR413 described with the CG at 10.5" He said after he moved it to 10.25" the problem went away. I have to agree with you that the flat bottom stab is probably the culprit. Does seem odd that it would nose dive if it's tail heavy but this seems to be the case. Let us know what the outcome is if you decide to move the CG back even further.

ORIGINAL: XJet

I'm beginning to think there is a lot of inconsistancy in the production of the tail booms/stabilizer in regards to incidence. Someone else reported the same problems you are having while others are flying with a 10.25" CG and no problems at all. How does yours react in full power vertical? Staight down at idle?

Ok, I have decided to order one of the 50 size. It asked me if I wanted the retract ready version, I didn't think it was even an option on the 50 size. Does anyone have this version? Is it OK or should I stick with the fixed gear version??? ANY advice would be appreciated.

i just ordered the falcon 120 from nitro models. $249 plus shipping. it says that expect shipment on 5/28, any one else looking at this big bobcat?

Hey there Brother... slowly getting ready to fly again. Great to see you again CrashPro! I'll send you a E-mail soon.


Luftwaffe Oberst
AMA #856404
Radio Aero Modelers Club
Pulaski, NY

I have one of the retract ready versions. Ordered yesterday, received today. Not bad at all. Of course, I'm only ~60 miles away from Nitro Models, but I couldn't drive there and back for the $14 they charged to ship (gas is $3.50/gal. here).

In any event, I've only taken a quick look at the plane/instructions. The wings are covered over solid, so I'll have to cut into one to see what all is underneath. From a review of the instructions, the kit is set up for retracts (including plastic wheel wells), but can be converted to fixed gear by adding some supplied gear blocks. It looks like the retract version includes the fixed gear/wheels as well.

It'll be a few days before I can get started on it, then I'll post up some pictures.

Man that Super Bobcat Looks Sweet

I wish they wouldnt have done that !!


Jason


http://www.nitroplanes.com/fa120nigasje.html

Somebody very early on in this thread was going to put a symetrical stab in it, but I have seen any flight reports..... It would be almost worthwhile to recontour the bottom of the stab to match the top, and see what effects would be...

Thanks Robert92679, I appreciate the reply. I think I'll go ahead and order mine now "retracts ready".[8D]

Hi everybody, I'm finishing my new Bob Cat and I'm going to balance my plane, but I want to know Where is the CG? I put air rectratil landing gear, OS 55 AX and Rossi pipe in my plane.

Hmm... Am I seeing flaps under the wing??

The dimensions of the super falcon are now very close the BVM Bobcat. The Nitro models Bobcat is in my mind a different plane that BVM does not offer the modeler. IMHO the super falcon is really pushing the limits on duplication at least they gave it a different name. I may end up buying one of these at some point if I can wrap my conscience around it.

I wonder how fast the super bobcat [or falcon] will go the bobcat to me is pretty fast any faster and it seems to me it would get away from ya $300 for the plane $300 for motor plus 9 servos ?? 14 to 16 inch prop !! i dont know it seems like overkill to me but like everyone else I will most likely get one.

Cg seems 2 be 10.25 to 10.50 for the last guy

AGR you get one and do a review then ill see

Jason