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Bobcat Finished

Old 04-25-2002, 12:35 AM
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rcpete347
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Default Bobcat Finished

Hi all just got my bobcat finished tonight and thanks to David Reed for solving my retract problem.
With 2 1400 mah. batteries for the receiver and 1 1200 C cells for the ECU the cat came out at 19.5 Ibs.
Sounds a little heavy ?
Has anyone flown a 19 to 20 Ibs. Bobcat .
Thanks Rcpete
Old 04-25-2002, 02:03 AM
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RC50
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Default Bobcat Finished

Congradulations! Let us know how she flies.
Old 04-25-2002, 02:53 AM
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Default Bobcat Finished

The one that I flew weighed the same. It flew great in 90 degree weather at an altitude of 3300 feet.

Mike Danchak
Old 04-25-2002, 03:09 AM
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Harley Condra
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Default BobCat weight

Pete,
My BobCat XL with a RAM 1000R X series and a clear coated six colored paint job weighs in at a whopping 19 lbs. 6 oz.(dry) with only one battery. Thats only 2 oz. lighter than yours that has two batteries! That is a very small percentage of the total weight. When I had the airstart 750 PLUS installed, it was 19 lbs 10 oz. by the time I put 6 oz. of lead in the nose to get the CG correct. I reduced the weight by a doing a small amount of equipment relocation when I installed the 1000R.
At the heavier weight, it was still a real floater in the pattern, and when wide open was extremely fast. (you should see it now). A normal takeoff roll at sea level was around 100 feet, and with the 1000 it will get off in about 75 feet or less.(hard surfaced runways). I wouldn't worry about the weight of your BobCat. It's right in the ballpark.
Your'e Going to love it!

I'm flying mine with the Tony F. JR 10X program that can be found in his trimming article on the BVM website. It uses all 10 channels, but gives you the maximum in surface adjustability and expands your ability to trim the airplane. Tony really knows what he is doing, and I will recommend his program to one and all.

Good luck with it, and I hope you like it as much as I like mine.
Let us know how it flies!
Harley Condra
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Buy American!!!!!!
Old 04-25-2002, 03:53 AM
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Silver182
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Default Bob Cat XL @ 19.5 lbs / Monocoted flying surfaces!!

Rcpete,
Just flew the maiden flight on my Bob Cat yesterday evening, OAT was 75 degrees, wind about 12 mph gusting to 15 out of the Southwest. Our field here in Denver is at 5600 MSL, I would guess a density altitude of about 7000 feet MSL,. Runway heading for this flight was West. (Quartering cross wind)

The "weight" of my Bob Cat XL would be slightly less than 19lbs, but I have incorporated the "Rat Trap" for near perfect on board generated RF suppression. The clean baseline range of the 10X modules that I am using is 2800 feet (full antenna check). Turbine operating at full power the range is reduced to 2650 feet, ruffly 1/2 mile! I am using the newest Jet Cat software and ECU, version 4.0/d. The only RF noise I am noticing now is from the fuel pump itself, and that is easily controllable by receiver antenna placement. The new Jet Cat ECU & software is a great improvement, generating less RFI over what some of the earlier ECU's were producing. The Traps box only weighs a couple of oz, but the fully double shielded set of cables add another 6 to 7 oz. The Rat Trap was designed for the earlier ECU's, but helps with the last remaining RFI generator the fuel pump.

The Bob Cat handles nicely, I didn't notice any weight factors at all. "Do not over control the ailerons, they are very effective." Make sure you allow yourself some exponential to desensitize the centering!

I had the airspeed pitot control set but never let it unwind to engage it. The setting was 250 kilometers or about 155mph. I did one vertical climb in which I opened up the P-120 but I quit long before I any vertical speed was lost!

The flight lasted until my countdown timer on my radio went off at 8 minutes. I was trimming out the three Mode settings which include (flaperons) with small flap movements 8% and 12% respectively, not needed with the Bob Cat, but I am using the modes so I will be able to trim out my testing of Crow or Butter flying of the Rudders. The use of mode will allow re-triming automatically!! I didn't get that far during the first flight but will in the next couple of flights.

The fact is I was having so much fun I wasn't ready for the timer. so I dumped the Bob Cat toward the runway threshold just like a potential dead stick landing, came across the numbers a little hot. I wasn't sure how much fuel was remaining in the tanks! (Upon inspection I had 1/2 of the 24oz aux tank Plus the UAT remaining or about 16oz not all burnable of course!)

The touch down was at about the 1/4 runway point and I was turning around for taxi back, at about 3/4 runway point. Our east / west runway at Chatfield Aerodrome, South of Denver is 700 feet in length. I was delighted to see the airspeed bleed off nicely even though I didn't raise the nose on approach, like I expect to normally. I didn't raise the nose until flair out. The wing on the Bob Cat has enough drag to be controllable similar to some our bigger sport prop jobs. The gear doors also do a job, I'm sure!

This bird will move make no mistake about that, I think the 175mph speed limit BV has required is conservative easily obtainable with the higher thrust turbines. I actually am going to back the pitot speed limiter down to close to what BV wants for the next few flights. He recommends 120mph for the first 10 flights or so, a good safe idea!! Checking the hinging and control surfaces carefully ----------
Lee H. DeMary
AMA 36099
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Old 04-25-2002, 11:15 AM
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KXH121
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Default Bobcat progress

Good to hear all of the good information you guys are putting out about your finished BC's. I am starting on the Fuselage portion and that should go rather quickly. The only hold-up will be trying to decide what paint scheme to use on the XL. BTW, anyone using the AMT AT-180 in their BC? Ideally the jet should weigh between 18-19lbs dry but I am going to use 1.5 oz cloth on the wings instead of what I normally use (.66 cloth). Hopefullt fully loaded it should stay under 20lbs. Any other flight information?
Old 04-26-2002, 06:46 PM
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SA Jet Jock
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Default JR10X Program

I cannot seem to find the TonyF article on JR10X programming on the BVM site. Where exactly is it located?

SA Jet Jock
Old 04-26-2002, 06:50 PM
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Default JR10X Program

OK found it under BobCat XL page
Old 04-29-2002, 03:37 PM
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DavidR
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Default Bobcat Finished

Pete,

Glad to hear your getting ready to fly it. Mine weighs right at 20 pounds with a P-120 on it and the UAT full of fuel.

Just got back from the Central Texas Jet Rally in Ausitn this weekend. I put a bunch of flights on the Bobcat. I just added the speedlimiter and played with it and the cruise control for the weekend. I have mine set at 175 mph and checked max speed after every flight. I have around 50 flights on the plane now and am very confident in the structural integrity of the airframe, and my building job. This thing is awesome, the more I fly it the more I enjoy it. I was consitently off the ground in 50' and pulling straight up and rolling until I got tired of going up. Max speed I hit was around 200 mph but average speed was usually around 120-140. The wind was blowing pretty hard (15-25 mph) and gusty and the BC handled it well. Landings were short with about a 75-100' roll out. It lands longer when the wind is not blowing. I have also found that if you throw the gear out while making a turn you will not notice any ballooning at all. The Jetcat was flawless.

David Reid

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