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KMP F-7F Tigercat

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Old 02-18-2012, 12:40 AM
  #2001
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Default RE: KMP F-7F Tigercat

I'm running the std Gen 2's but with robart valves etc. I hear the new ESM electric ones are pretty good.
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Old 02-18-2012, 01:02 AM
  #2002
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Default RE: KMP F-7F Tigercat

I will have the electric retracts offered by ESM for mine. It will not be till next month or more though as TBM are still back ordered with them. They recieved 10 gear sets with the new shipment yet had 11 on back order. I will also use the Sierra Brakes with this gear set.
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Old 02-19-2012, 10:48 AM
  #2003
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Default RE: KMP F-7F Tigercat

Yer, I wish I had brakes on mine. These suckers roll for miles on landing, even on grass! Would make life easier....
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Old 02-23-2012, 08:32 PM
  #2004
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Default RE: KMP F-7F Tigercat

ysolomon
Well, I decided to go with the eflite 160s and ordered two of them. I also sold the 110s on ebay to help with the cost of the upgrade. Now for a new battery or two and new props.
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Old 02-24-2012, 04:22 AM
  #2005
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Default RE: KMP F-7F Tigercat

Eagle

E flite makes good motors. As far as batteries, I'm planning on using two 6S 8000mah 30C flightmax batteries in series, and connect to both motors in parallel. This way, you never have to worry that one side runs out of battery alone. They should be able to supply 240A total. I don't expect to consume more than 80A per side even at peak (3500W...)
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Old 02-24-2012, 08:08 AM
  #2006
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Default RE: KMP F-7F Tigercat

Hello !
Following the documentation from e-flite, the 160 is designed for 10s LiPo (not 12s), max power is 2700W (not 3500W).
Very similar is fact with the Scorpion S5525-225 I use on my Mossie with 3-blade Gsonic 18"*12" propeller.
ESC is CC ICE2 HV80 and batteries are two 12s2p a123, one per motor to avoid ripple interference.
I use two iCharger 3010B to charge in 15min max.
Both batteries are checked by telemetry, setting an alarm off when it's time to land.

The alternative was to use one bigger battery in the nose, raising several problems...
* structural problem with 3.4kg in the nose when hard landing... now its 1.7kg on each wheel...
* no charger big enough for fast charging...

I am looking for some automatism to maintain control in case of motor failure :
* gyro on aileron and/or rudder
* some electronics to synchronize both motors, automaticaly reducing power on the other motor in case of failure and giving control back later.

I lost my 2.7m PiperCub for a stupid reason : the ESC burned at takeoff and didn't ear the motor shutting down.
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Old 02-24-2012, 11:12 AM
  #2007
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Default RE: KMP F-7F Tigercat

ramboman i think you can use a twin sink for gas glow engines on your electric set up. you will just need to mount a magnet on each motor somewhere. also TP has a new charger out that can charge at 1,000 watts thats 20 amps at 50 volts...


I just got my tracking number yesterday from TBM for my shiny F-7F. I can wait to get started.......
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Old 02-24-2012, 05:12 PM
  #2008
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Default RE: KMP F-7F Tigercat

2 E-flite power 160's 2 castle creation HV 85’s (with extra capacitors) 2 10s 5000mah (2-5s 2-3s 1-4s packs for proper balance) Thunder power 45c packs(8C charge rate) 4 FMA Power lab 8's (1344 watts 26v input) all charged in under 10 minutes! PROBLEM SOLVED!

LINK TO BATTERY
http://thunderpowerrc.com/G6ProPerfo...oBatteries.htm

LINK TO CHARGER
http://www.revolectrix.com/pl

Where do you put the batteries in the nacelles and how is the CG. What if you lose one battery pack? (I have had 2 different problems that I believe would have caused a 1 engine out scenario if both packs would have been separate)
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Old 02-24-2012, 10:00 PM
  #2009
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Default RE: KMP F-7F Tigercat

The risk is one pack going empty before the other... I have to manage that !
I don't expect a pack to fail... but a controller may fail... I lived that twice !
For inline motors like the Mossie or the P51, the pack is in a ctp tube going thru the firewall and carrying the brushless at the front.
For radials like the P47, the Zero or the Swordfish, the pack is mounted in front of the firewall, around the brushless.
The pack is not designed to be easily removed; not needed !
For proper CoG on the Tigercat, I should build a false radial with a ring of cells like I did for my Swordfish.
The iCharger 3010B are also 1000W each... with one pack, I need to split the pack for charging... witth two packs, I don't need to.
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Old 02-25-2012, 12:14 AM
  #2010
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Default RE: KMP F-7F Tigercat

Twinsync seems to be the right answer, combined with a gyro on the rudder.
Thanks
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Old 02-25-2012, 10:25 PM
  #2011
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Default RE: KMP F-7F Tigercat

A gyro on the rudder does work well, BUT make sure its on rate mode not heading hold, and it helps to mix in a tiny amount of aileron to rudder mix. That way when you turn the gyro sees an input and doesnt keep trying to correct the turn with opposite rudder (fatal on the tigercat!). Or you can just use rudder in the turns.
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Old 02-25-2012, 10:40 PM
  #2012
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Default RE: KMP F-7F Tigercat


Quote:
ORIGINAL: stoat

A gyro on the rudder does work well, BUT make sure its on rate mode not heading hold, and it helps to mix in a tiny amount of aileron to rudder mix. That way when you turn the gyro sees an input and doesnt keep trying to correct the turn with opposite rudder (fatal on the tigercat!). Or you can just use rudder in the turns.
Excellent... I didn't know how to solve that issue... Thanks
I will forget about Twinsync... even Bill is not convinced...
May be an idea to solve the "one battery low" issue...
I have two batteries, one per motor in each nacelle...
A solution may be to connect both batteries in parallel with a cable between them so that they are kept at the same level.
Would that raise unexpected problems ?
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Old 02-26-2012, 10:44 AM
  #2013
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Default RE: KMP F-7F Tigercat

I have run several twin EDF aircraft over the years and usually had 2 seperate power systems. I have run a parallel setup like you mention with no problems at all. Just requires a bit more wiring and you have to be very careful if you are running two lots 2 x 6 cell packs when you are connecting them up. Make sure you colour code your plugs! Not just red/black but a different colour for each plug pair. At the size you are running I have seen a 6mm plug vaporise instantly without even touching the one it was about to be shorted against - just the arc was enouth (about 10mm apart!). Left a good size burn on my hand too!

Also make sure you run a spark arrester (resistive jumper) for when you first connect EACH esc. Again, the spark will weld plugs together...
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Old 02-26-2012, 02:35 PM
  #2014
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Default RE: KMP F-7F Tigercat

I have those spark resistors on anything I fly beyond 6S. Do you know that Castle Creations tell you that "the spark is your friend?" (see last question in http://www.castlecreations.com/suppo...hoenix_hv.html). I understand their logic, claiming that if you don't see a spark, you might have bad capacitors, but I agree with youtoo many of those sparks, especially in those high voltage, high current systems, will just destroy the connector.
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Old 02-26-2012, 02:56 PM
  #2015
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Default RE: KMP F-7F Tigercat

"the spark is your friend?"...really? I wonder about Castle some times.... Anything that produces a spike that big cannot last for too long! Its hard enought keeping the smoke inside CC products as it is....
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Old 02-26-2012, 10:30 PM
  #2016
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Default RE: KMP F-7F Tigercat

I use SPS from Emcotec to disconnect the batteries... it's an electronic switch... it suppress the spark too.
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Old 02-28-2012, 04:01 PM
  #2017
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Default RE: KMP F-7F Tigercat

Two more days till i get my shiny F-7F.......

Does fiberglass specialities make a more scale cowl for this plane?

i have been thinking of a four stroke instead of the DLE 30's has anyone flown the Roto motor 35FS? the Saito 200 might be good also if can lug in down some to get a better sound.
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Old 02-28-2012, 08:07 PM
  #2018
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Default RE: KMP F-7F Tigercat

I just bought my 2nd NIB OS 120 SP. It’s the best 4cycle I have ever owned . If I get tired of the electric set up on my t-cat I might do an electric to glow conversion!
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Old 03-20-2012, 12:58 PM
  #2019
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Default RE: KMP F-7F Tigercat

Who make a good scale dummy engine for this plane?
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Old 03-26-2012, 04:22 AM
  #2020
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Default RE: KMP F-7F Tigercat

Finally got mine in the air after being in a box for two long, flies like a dream, a bit of down elevator mixed in with full flap means she comes in so sweet.
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Old 03-26-2012, 09:17 AM
  #2021
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Default RE: KMP F-7F Tigercat

Very nice flying shots Kniver.. Your photographer did you well. My F7 won 2nd place in Scalemaster qualifier last year. It was kinda nice to see the lines and scale authenticity prove itself. The little light fixture behind the second cockpit, however, cost me.. The full size Big Bossman does not have that light on it. It is inaccurate to the plane it was modeled after.
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Old 04-02-2012, 03:03 PM
  #2022
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Default RE: KMP F-7F Tigercat

Greetings All...

Earlier posts on here say the engine cowl diamenter is 190mm. (7.48 in) However "Troy Built Models", who now sell parts for KMP/ESM says its 8 in.

Can anyone clarify the actual dimensions of the engine cowls?

Thank you, Dave
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Old 04-02-2012, 03:21 PM
  #2023
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Default RE: KMP F-7F Tigercat

See Page 75. I measured them from inlet to out.
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Old 04-02-2012, 06:43 PM
  #2024
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Great! Thank you.
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Old 04-18-2012, 06:11 PM
  #2025
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Default RE: KMP F-7F Tigercat


Here is mine taken at the Wings over Arizona fly-in last weekend.
Bob

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