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        Build Log Fightercat Cheetah - Red Bull Twin

#1 bill34207 Apr 26, 2012 07:43 PM

Fightercat Cheetah - Red Bull Twin
 
4 Attachment(s)
My Cheetah hull arrived today. I have to say the packaging on these is nice.

It's really light (almost scary light) The hull & hatch by themselves come in at 3 lbs and less than an oz. It's just a hair too long for classing as a P boat by NAMBA specs though. Mine measures at 34 and 1/16". Close enough in my book but a real stickler for rules could still bust you in a race determining situation. If you're going to run P, better take a sanding block to the tips of the sponsons or something. Since my plans are for Q it's not an issue for me.

I'm looking at making it a twin so will only be able to run 1p on the packs. (One downside) I won't be able to use a single 6s pack per motor either. The only place big enough to slip one of my 5000 ma 6s packs in is at the rear where the rise in the hull is (and where the motors will be). A couple of 3s packs in series can be slid in up front with no problems though.

#2 scorpion1 Apr 26, 2012 08:50 PM

What motors?

#3 bill34207 Apr 26, 2012 09:03 PM

Quote:

Originally Posted by scorpion1 (Post 21447008)
What motors?

I'm thinking the same thing as madphil has in his Falcon. The HET 700-68/1680's or possibly go to the 1500's for better run times. I have local supplier for them with William from turbofanelectrics.com He'll treat me right on them even though I haven't bought a lot from since getting more into boats than jets.. He has the 1500's in stock but would have to order in the 1680's if I want them.

#4 scorpion1 Apr 26, 2012 11:14 PM

You may consider saving some big bux and checking these out................they would really rock on 6s!!

http://www.hobbyking.com/hobbyking/s..._Inrunner.html

#5 madphil Apr 27, 2012 02:29 AM

looks good bill ,
you can use your 6s packs if cut off the heat shrink split the packs into 2 x 3s packs then re heat shrink the packs the balance wires and connecting leads are long enough to do this without re soldering we do this in racing because a single 6s pack is lighter than 2 x 3s packs and you can still charge as a single pack

#6 bill34207 Apr 27, 2012 05:35 AM

Quote:

Originally Posted by scorpion1 (Post 21448141)
You may consider saving some big bux and checking these out................they would really rock on 6s!!

http://www.hobbyking.com/hobbyking/s..._Inrunner.html

Definately cheaper. Could probably get 3 of those for the price of one HET or 6 for the price of one Neu 1515. Not impressed by the specs on them though. Rated for 4s max and only 815 watts.

Even though I haven't tried the 700 series, I've used many of the smaller HET's in 70 mm edf's and they hold up well spinning high rpm's. I had one of their 28mm motors (2W-20) that made more watts in a 70 mm fan than the Turnigy's are rated for. Still have the motor although the airframe suffered from "sudden deceleration trauma" a couple of years ago.

#7 scorpion1 Apr 27, 2012 07:15 AM

Quote:

Originally Posted by bill34207 (Post 21449473)
Definately cheaper. Could probably get 3 of those for the price of one HET or 6 for the price of one Neu 1515. Not impressed by the specs on them though. Rated for 4s max and only 815 watts.

Bill, those bogus HK specs cant be trusted............... you can set it up to pull around 60-70 amps(rated at 55), on 6s that's about 1500 watts which is more reasonable for that size motor.

Those HET's do look good though.................:)

#8 bill34207 Apr 27, 2012 07:51 AM

Here's the HET spec sheet for the 700-68 series. http://www.highendrc.com/member/3170...8motorspec.pdf
William tells me he's pulling close to 4000 peak watts on one of the 1500kv in a 90 mm fan.

#9 scorpion1 Apr 27, 2012 08:09 AM

Are they 36mm dia. or 39 +/- ?

#10 bill34207 Apr 27, 2012 08:48 AM

Quote:

Originally Posted by scorpion1 (Post 21450253)
Are they 36mm dia. or 39 +/- ?

The 700 series are 39 mm the 600 series are 36 mm. I have a couple of the 600's still in use in mild (1700 watt +/-) 90 mm edf setups.

Here's one
Sniper90-2.wmv (5 min 29 sec)

#11 Pseudonym Apr 27, 2012 10:55 AM

Any plans on what you are using for hardware yet?

#12 bill34207 Apr 27, 2012 12:00 PM

Quote:

Originally Posted by Pseudonym (Post 21451436)
Any plans on what you are using for hardware yet?

Just ordered a couple of these for stingers. http://fightercatracing.com/index.ph...emart&Itemid=1 (same as used on the DF Explorer when I built it) I had a couple of Speedmasters laying around but they are too tall for the sponsons with the overhang above them. Haven't decided on a rudder just yet. I need to see how far back the stingers will be in relation to the overhang before deciding on amount of setback needed for this hull.

#13 Pseudonym Apr 27, 2012 12:37 PM

Quote:

Originally Posted by bill34207 (Post 21451937)
Just ordered a couple of these for stingers. http://fightercatracing.com/index.ph...emart&Itemid=1 (same as used on the DF Explorer when I built it) I had a couple of Speedmasters laying around but they are too tall for the sponsons with the overhang above them. Haven't decided on a rudder just yet. I need to see how far back the stingers will be in relation to the overhang before deciding on amount of setback needed for this hull.

Those stingers will definitely put the props well behind the hull. Fighter cat has another stinger that is shorter than the 110mm, did you see those?

#14 bill34207 Apr 27, 2012 01:06 PM

The shorter 78 mm he has two different ones of. The mono stinger is about the same size as a speedmaster and too tall. The other one is for a 4 mm shaft. I like running the .187 (3/16") size for a better prop selection.

#15 madphil Apr 27, 2012 01:29 PM

Quote:

Originally Posted by scorpion1 (Post 21450253)
Are they 36mm dia. or 39 +/- ?

they are 39mm most of the guys in our racing club use HETs big power for the size not cheap but i think worth the extra money , they also do a longer 92mm x 39mm can,
a bit more power they can all stand high RPM without problems and good run time


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