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KMP F-7F Tigercat

Old 07-30-2008, 10:21 PM
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Default RE: KMP F-7F Tigercat


ORIGINAL: VKerster

CHSARB, T-CAT #2 WIEGHS IN AT 30 LBS. EVEN, WITH THE G- 26'S AND 6 OZ OF LEAD IN THE NOSE. AND 28 OZ. FOR FUEL, AND IT'S AT 31 LBS. 12 OZ TAKE OFF WEIGHT. T-CAT #1 WAS ABOUT 28 LBS. WITH THE FUEL. THE NEW SKIN KMP IS USING MUST BE HEAVIER, BUT 2 LBS. WORTH??? HOPE IS FLIES
Hi there Vkerster and co.... although it may be a little late but why don't you go with the MVVS 26cc motors there petrol but in the casing ofa nitro motor, I would think you could at least halve your engine weight...
Old 07-31-2008, 12:57 AM
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Default RE: KMP F-7F Tigercat

Hi Jack, I covered the touch-up paint situation back on Pg. 15 #375. Klass Kote paint is EXCELLENT.

Col. Chuck Winter
Old 07-31-2008, 02:37 AM
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Default RE: KMP F-7F Tigercat

Hi VKerster,

dont worry. My TC weights exactly the same witht 14 kg = 31 lbs and flies excellent !!!

@bignuts181: I prefer the Zenoahs because of the magneto-ignition system. I do not need any additional batteries for the ignition and I do not have any components which could fail. Other advantage of Zenoah is the matter of fact, that we can use very short mufflers because of the soft inlet/outlet timing of the Zenoahs.

MVVS and other engines like 3W, DA and others are using very sharp inlet-/outlet timing and due to this matter of fact they are requesting long mufflers to get performance and to avoid overheating the engines.

Long mufflers could be a problem with the design of the nacelles of our TC´s and also could move the CG far back.


best regards

Detlef
Old 07-31-2008, 10:38 AM
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Default RE: KMP F-7F Tigercat

BIGNUTS181, EVEN WITH THE G-26'S , MY T-CAT NEEDED 6 TO 12 OZ. OF LEAD IN THE NOSE TO BALANCE, SO THE WEIGHT OF THE ENGINES MAKING IT HEAVIER ISN'T REALLY THE ISSUE. THIS BIRD HAS A VERY HEAVY TAIL BOOM. THE PLANE IS WHAT IT IS ,AND REQUIRES LOTS OF WEIGHT FORWARD OF THE DESIGNED C.G. POINT TO BALANCE....
Old 07-31-2008, 07:49 PM
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Default RE: KMP F-7F Tigercat


ORIGINAL: VKerster

BIGNUTS181, EVEN WITH THE G-26'S , MY T-CAT NEEDED 6 TO 12 OZ. OF LEAD IN THE NOSE TO BALANCE, SO THE WEIGHT OF THE ENGINES MAKING IT HEAVIER ISN'T REALLY THE ISSUE. THIS BIRD HAS A VERY HEAVY TAIL BOOM. THE PLANE IS WHAT IT IS ,AND REQUIRES LOTS OF WEIGHT FORWARD OF THE DESIGNED C.G. POINT TO BALANCE....
Hi there VKerster I understand that this is a heavy plane but what I am getting at is that instead of carrying ballast over the G of G you could have a model with the same or close to the same nose weight but with a less overall mass. In theory you could save a couple of pounds off the bottom line so instead of having a 30lb model you could have a 28 lb model and hence a lighter wing loading!....do you see my point?
Old 07-31-2008, 10:02 PM
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Default RE: KMP F-7F Tigercat

I'm a little surprised that all these Tigercats are coming out that heavy. The one I built comes in about 22 pounds less fuel and flies beautifully. There is no added ballast; we got over the tail heavy condition by using one carbon fiber pushrod for the elevator, pull-pull on the rudder and putting all the batteries in the extreme nose. CG is right on the money. I think gassers might be little heavy for this model. The YS-120 four strokes we used have plenty of power are are lighter than the equivalent gas engines.

Has anyone else flown yet?
Old 08-01-2008, 02:28 AM
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Default RE: KMP F-7F Tigercat

My Tcat weighs 25lb with 2x Zenoah 20 and the performance is superb. I must admit 30lb plus is getting rather heavy giving a very high wing loading. Having said that everybody has there own opinion on there prefered powerplants.
Cheers richard.
Old 08-05-2008, 09:36 AM
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Default RE: KMP F-7F Tigercat

PYLON2, 99% DONE WITH T-CAT #2, HAVING ISSUES WITH THE KMP RETRACTS. THESE UNITS DON'T WANT TO SPRING DOWN AND LOCK CORRECTLY. AM USING 95 PSI IN THE LARGE ROBART AIR TANK. THEY ACT LIKE THE RETURN SPRINGS AREN'T STRONG ENOUGH TO DEPLOY AND LOCK THEM. ANYONE ELSE HAD THIS ISSUE. THIS IS HOLDING UP MAIDEN FLIGHTS.[:@]
Old 08-05-2008, 11:40 AM
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Default RE: KMP F-7F Tigercat

kverster,
sounds like your valve isn't adjusted correctly but I'm sure you've checked that???
unhook the servo and manually trip the valve to see if it still does it. I changed mine to a SPRING AIR valve and that cured that. Unfortunately, the mains on mine leak so bad that they won't even go up in the wells! In fact, I've not flown one flight yet with the gear up......
good luck and let us know how the maiden goes.
Regards,
F82FAN
Old 08-05-2008, 12:51 PM
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Default RE: KMP F-7F Tigercat

F8, I 'M USING A ROBART AIR VALVE, AIR TANK, AIR FILLER CHUCK, AND PRESSURE GAGE,AND AIR LINES AND CONNECTORS. ALL ROBART EXECPT FOR THE RETRACT UNITS (GEN. 5), STRUTS, AND WHEELS. I MISPOKE ON MY LAST POST. THE MAIN LEFT SIDE WORKS, IT'S THE RIGHT MAIN AND SOMETIMES THE NOSE GEAR THAT DOESN'T WORK RIGHT....
Old 08-05-2008, 02:22 PM
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Default RE: KMP F-7F Tigercat

Hey V,
No offense misspelling your name - I had my iphone and was reading the micro-writing!
So, you did like any person with common sense would do and just changed EVERYTHING except the units!!!!
We did that too, but the units themselves just ain't gonna cut it.
I hate to suggest taking them apart, but a quick shot of teflon (or similar) lube into the air inlets of each unit with the hose disconnected might cure your ailment. You could "break them out of lock" and cycle them with one hand and spray lube into the inlet tube with the other....
You might ask KMP what type of O-rings are in the units to make sure that any lube you use is compatible and won't mess up the O-ring.
Good luck!
F82FAN
Old 08-05-2008, 03:09 PM
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Default RE: KMP F-7F Tigercat

Hi VK From Col. Chuck Winter, I have probably spent more time SCREWING around with my Tiger Cat than any of my Ducted Fans, Turbines, Giant Scale Racers etc.etc. I went along with KMP recommendations with engine size (RCV 91) their retract system etc. etc. I have now seen THE LIGHT. I have mounted 2 Fuji 24cc engines with magnetos and in the process of installing Sierra Retracts. I could have saved a lot of money and time if the importer would have done their HOMEWORK... I suggest you ROB the cookie jar and get some Sierra retracts, they are IMPRESSIVE.

Col. Chuck Winter
Old 08-05-2008, 03:11 PM
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Default RE: KMP F-7F Tigercat

I must admit I had trouble with the nose retract struggling to lock in both positions. I eventually fitted the retracts Century Jet make for the Tcat. These are superb although quite a bit heavier. They also have the air control valve to limit/adjust speed. To be fair to kmp though, there retracts are alot cheaper and made to a budget to keep the cost of the kit down.

Good luck with the maidens !!!! Richard.
Old 08-05-2008, 05:17 PM
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Default RE: KMP F-7F Tigercat

It seems that to keep the cost down even more would be to take out the retracts all together as it appears that different units are replacing the stock ones anyway. Then adjust the price accordingly. Then take the savings and put retracts in of your choice.
Old 08-05-2008, 06:21 PM
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Default RE: KMP F-7F Tigercat

makes good sence to me.
Old 08-06-2008, 07:53 AM
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Default RE: KMP F-7F Tigercat

Hi VKerster,, Please excuse my ignorance if this is the case but my understanding was that the Gen 5 retracts are air up and air down,,where as the gen 4 are air up and spring down. Cheers..
Old 08-06-2008, 09:47 AM
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Default RE: KMP F-7F Tigercat

COL. WINTER, I HAD LENGTHY DISCUSSIONS WITH KMP ABOUT ENGINE CHOICES AT THE BEGINNING OF MY T-CAT "JURONEY", AND DECIDED 2 .91'S (30 CC'S) TO PULL UPWARDS OF 30 LBS. WAS WAY UNDERPOWERED TO SAY THE LEAST. MY FIRST T-CAT WAS AN AWESOME PERFORMER WITH THE G-26'S. USING THE SAME G-26'S ON T-CAT #2 WITH APC 16X10'S. ALSO USING A FUTABA SERVO SINCRONIZER FOR SINKING THE THROTTLES. THIS COMBO PULLS LIKE A 747, IN MY BOOK TOO MUCH IS JUST ENOUGH. I THINK YOUR CHOICE TO GO WITH TWO 24 CC GASSERS IS A GOOD ONE. I CHECKED KMP'S WEBSITE, AND THEY ARE CHARGING $300.00 FOR THEIR WEAKLING RETRACTS.[:@] I NEED TO SAVE UP FOR THE SERRIA UNITS. FRUSTRATING, THIS IS HOLDING UP THE MAIDEN.....
Old 08-06-2008, 02:37 PM
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Default RE: KMP F-7F Tigercat

CORD, THESE UNITS ARE AIR UP, SPRING DOWN, SO I GUESS THE'RE GEN 4S....
Old 08-09-2008, 03:01 PM
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Default RE: KMP F-7F Tigercat

[link]http://www.youtube.com/watch?v=GLXjU8wJqYA[/link]

This may have been posted before, but its still a great vid..
Old 08-11-2008, 10:21 PM
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Default RE: KMP F-7F Tigercat

Help! With gear down I am nose heavy, with gear up I am tail heavy. Which way is correct. Plane is dry, with all batteries, props, hubs and cowls. Need suggestions. Will gat a scale tomorrow to weight the plane. No ballast added at this point. Evoultion 26's, sierra gear.
Thanks
Jack
Old 08-12-2008, 02:00 AM
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Default RE: KMP F-7F Tigercat

Morning Jack,

Which variation of CG you have betwween gear up and down (in mm or inch) ?

I balanced my TC with gear up and move CG about 10 mm to the nose with gear down.

In flight I did not need to modify the trim with +/- 10 mm CG variation.

Cheers, Detlef
Old 08-12-2008, 06:50 AM
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Default RE: KMP F-7F Tigercat

Hi!!
I used this technic for balancing my tigercat "Vanessa CG Machine"
Is anybody as used this ??, anyway I used this for balancing my topflite GS corsair, and it's very accurate
I put 12oz of lead in the nose and the plane seam to be balance perfectly, but...
with all gear down and the plane on the ground the nose seam to be very light
if I put the tail on the ground, the nose stay in the air, but if I raise the tail just a littlie bit, the nose came
down, I did some taxi on the grass and the nose stay on the ground, I'm not sure if the plane
is balance well, is it normal that when I put the tail on ground the the nose stay in the air??

thank!
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Old 08-13-2008, 02:45 AM
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Default RE: KMP F-7F Tigercat

As long as you have balanced it where stated(117mm) with wheels up and the aicraft slightly nose down, the C.G will be fine. My problem was that the main wheels were angled slightly forward towards the noseleg which was making the aircraft sit on its tail easily. All i did was put some angled shims(3mm to nothing) under retract units to slightly angle back the mains. This also helps the wheels retract completely into the nacelle. This totally cured mine. Hope this helps. Richard.
Old 08-14-2008, 05:01 PM
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Default RE: KMP F-7F Tigercat

JBW, USING THE C.G. POINT IN THE DIRECTIONS, T-CAT #1 TOOK 12 OZ. OF LEAD IN THE NOSE MOUNTED BY THE NOSE GEAR DOORS AND THE GEAR UP, TO BALANCE SLIGHTLY NOSE HEAVY. THE PLANE FLEW AND LANDED VERY WELL WITH THIS AMOUNT OF LEAD. T-CAT #2 USING THE SAME RADIO, ENGINES, ETC., LOCATED IN THE SAME AREAS OF THE PLANE TOOK ONLY 6 OZ. TO GET THE SAME RESULTS. I MARKED THE C.G. POINT IN TWO PLACES ON THE TOP OF THE WING, TOOK A STRAIGHT EDGE AND MARKED TWO DOTS AT THE WING TIPS, THEN HAD A HELPER AND MYSELF USE ONE FINGER AT EACH POINT AT THE WING TIPS AND CHECKED THE C.G. DON'T FORGET TO BALANCE THE PLANE AXIALLY AS WELL. (LEFT TO RIGHT. THIS IS VERY IMPORTANT, SHOLUD BE NETURAL.)
Old 08-19-2008, 05:23 PM
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Default RE: KMP F-7F Tigercat

YO, ANYONE OUT THERE?

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