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41 Falcon cat build

Old 11-11-2008, 08:43 PM
  #276  
rcboateric
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Default RE: 41 Falcon cat build

I got the prop from Chris, the mod is rounded ear and cupped, if you are running a 32% CG for it, that sounds a bit too low for the prop.


http://www.dasboata.com/

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Old 11-11-2008, 08:51 PM
  #277  
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Default RE: 41 Falcon cat build

My 41" Falcon CG 14" forward from transom CG is at 34%. If yours is 14.5" forward from transom then the CG is at 35.3% I'll check out the prop.
Old 11-11-2008, 09:03 PM
  #278  
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Default RE: 41 Falcon cat build

The CG is changable if you notice that 20* prop being flighty on your current setup, I dropped about 17 ounces epoxy to the nose to settle it down.
Old 11-11-2008, 09:11 PM
  #279  
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Default RE: 41 Falcon cat build

Ordered the 15* and the 20* I'm also building a AC Razer 45 v hull and want to try some diff props. If I get the props and have them by the weekend to try them out. Will keep posted.
Old 11-11-2008, 09:17 PM
  #280  
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Default RE: 41 Falcon cat build


ORIGINAL: Performance Unlimited

Ordered the 15* and the 20* I'm also building a AC Razer 45 v hull and want to try some diff props. If I get the props and have them by the weekend to try them out. Will keep posted.
You will love those props that you ordered, please make sure they're rounded ear and cupped...LOL
Old 11-12-2008, 02:22 PM
  #281  
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Default RE: 41 Falcon cat build


ORIGINAL: rcboateric


ORIGINAL: Performance Unlimited

Ordered the 15* and the 20* I'm also building a AC Razer 45 v hull and want to try some diff props. If I get the props and have them by the weekend to try them out. Will keep posted.
You will love those props that you ordered, please make sure they're rounded ear and cupped...LOL
Better off with pointed tips.....the round ear removes lift , Cats running 70+ need a bit of lift to get the boat riding almost level at speed.
Old 11-12-2008, 04:23 PM
  #282  
DaveMarles
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Default RE: 41 Falcon cat build


ORIGINAL: Performance Unlimited

The 1475 I run only has 2% slip. I guess I'll have to try the ABC prop. Where did you get the prop?
Only 2 % slip?. You are daydreaming !!!!!
Old 11-12-2008, 04:51 PM
  #283  
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Default RE: 41 Falcon cat build

Sorry ...typo it s/b 20% ( 5"pitch... 19,000 RPMS Theoretical Speed..90mph Actual 72mph ... 20% slip)

http://www.go-fast.com/Prop_Slip_Calculator.htm
Old 11-12-2008, 05:40 PM
  #284  
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Default RE: 41 Falcon cat build


ORIGINAL: Tahoe1970


ORIGINAL: rcboateric


ORIGINAL: Performance Unlimited

Ordered the 15* and the 20* I'm also building a AC Razer 45 v hull and want to try some diff props. If I get the props and have them by the weekend to try them out. Will keep posted.
You will love those props that you ordered, please make sure they're rounded ear and cupped...LOL
Better off with pointed tips.....the round ear removes lift , Cats running 70+ need a bit of lift to get the boat riding almost level at speed.
LOL...I'm not familiar with the pointed tip props anymore since I could use other method to balance its back, for the top speed, I prefer a round ear one.
Old 11-12-2008, 06:43 PM
  #285  
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Default RE: 41 Falcon cat build




The prop slippage for a Mono is 25%, Cat/Hydro is 20% and Rigger is 15%.

http://www.props4u.com/prop_chart.htm
Old 05-28-2009, 07:23 AM
  #286  
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Default RE: 41 Falcon cat build

Currently building the Falcon and thinking about using the 32% CG, like the way the boat in the video ran. If I need to put a small foil on the nose wan't be a big deal.
Using a skeged strut from accu-tech,and rudder from accu-tech.
Should I use only the 5/16 tude or both 11/32 and 5/16, just the 11/32 where it exits the hull?

Thanks Randy
Old 05-28-2009, 03:07 PM
  #287  
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Default RE: 41 Falcon cat build

I srt the CG at 34% due to the fact the falcon likes to fly at speeds over 65mph. I also added nylon tail skids for a tail dragger airplane that are at a 45 degree angle inside the pickle fork on each side at the front of the hull about 2 inches from the tip. An Octura 1475 Pitched to 5.3 inches with the drive tube 1/2-5/8 of an inch from the bottom of the hull center. The larger tube thru the hull and the smaller one slip inside. I drill the smaller tube and braze / solder a small verticle tube so I can oil the shaft without taking everything apart each time. Here ids the falcon running at 70 mph on a small lake.
Old 05-28-2009, 03:09 PM
  #288  
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Default RE: 41 Falcon cat build



youtube  linkhttp://www.youtube.com/PerformanceUnlmtd

Old 05-28-2009, 03:16 PM
  #289  
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Default RE: 41 Falcon cat build

Impressive speeds,was the second cat a Falcon?
Brod..
Old 05-28-2009, 03:27 PM
  #290  
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Default RE: 41 Falcon cat build

The wild black cat is a 30 inch nitro cat with a QD25 HT engine in it.....running it is like tilting a chair backwards....riding on the outer limits of reality
Old 05-28-2009, 03:42 PM
  #291  
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Default RE: 41 Falcon cat build

Your not kidding!! fabulous power!
Any chance of some pics of the mechanics??
great video....the best i've seen..
Brod..
Old 05-28-2009, 03:46 PM
  #292  
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Default RE: 41 Falcon cat build

Hey Les, what lake do you run in? I'm in St.pete and getting skiddish at woodlawn park...........................Bill Thanks
Old 05-28-2009, 04:15 PM
  #293  
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Default RE: 41 Falcon cat build



Bill- for Lake Info.... email me  for more details at [email protected] 

Old 05-28-2009, 09:22 PM
  #294  
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Default RE: 41 Falcon cat build

if you go with a 32% CG, you will never keep the boat on the water. stick with the 34with a dry tank.
Old 06-16-2009, 06:17 AM
  #295  
painman
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Default RE: 41 Falcon cat build

Strut height, Where are you that are running the 41 falcons setting the strut. I have been testing and the last time out the boat wanted to bounce, what would cause this? I might of had to much positive angle in the strut. I have reset and now have the strut 1/2 " above the sponsons w/o any angle. Any help would be appreciated. When I said 1/2 " I mean the whole strut not center, is this to high?

Thanks Randy
Old 06-16-2009, 08:40 AM
  #296  
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Default RE: 41 Falcon cat build

Mine is flat on the bench with a little neg. No bouncing.
Old 06-16-2009, 10:16 AM
  #297  
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Default RE: 41 Falcon cat build

I run my strut 1/2 from the bottom of the hull not the bottom of the sponsons with a 1475 pitched to 5.2" with 2-3 degrees of positive trim
Old 06-16-2009, 03:56 PM
  #298  
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Default RE: 41 Falcon cat build

thanks Paul and Les for the information, I will be making some adjustment and keeping notes where it seems to be best. Paul are you running the 2716 from Chris? and Les is the 1475 a 2 or 3 blade?

Thanks Randy
Old 06-16-2009, 04:58 PM
  #299  
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Default RE: 41 Falcon cat build


ORIGINAL: Performance Unlimited

I run my strut 1/2 from the bottom of the hull not the bottom of the sponsons with a 1475 pitched to 5.2" with 2-3 degrees of positive trim

Wow. That's totally different than mine. I know both boats are running in the 70's. That goes to show different set ups can be.

I'm running a R2716/2 15* with a QDHT. Mine actually gets slower when I raise the strut. I don't see how your getting away with positive trim. Mine will blow over if there is any positive in it.
Old 06-16-2009, 05:04 PM
  #300  
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Default RE: 41 Falcon cat build

The Octura 1475 is a 2 blade if there is a good chop or wind I usually trim in a bit. You can also put a strip of balsa that is 1/4" wide 1/8" thick and the lenght is 75% of the distantace between the sponsons up front. Position the wood in the center and 1.5-2" from the front on the bottom of the hull....this will still let the hull pack air and helps prevent blow over. Once you have the lenght soak the balsa in water so it will flex....then tape it to the hul so it will have the curve from left to right....paint it your color so it will be sealed and bond it as described above.

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