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KMP F-7F Tigercat

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Old 01-11-2013, 09:34 AM
  #2076  
carlosmalone
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Default RE: KMP F-7F Tigercat

The issue with the Dle rear carb engines is that the carb will need to be recessed into the firewall about 1" to get the required 135mm to the backplate. Also the rear mufflers on the DLE 35 may not clear the nacelle. It may work with some major surgery.

Look at the twin sync unit at troybuilt.

Carl
Old 01-11-2013, 09:41 AM
  #2077  
flytaildragger
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Default RE: KMP F-7F Tigercat

My thoughts are to install a Twin Sync... The unit syncs the engines electronicly and You have a failsafe built in that so if you lose an engine, it pulls the throttle back on the other engine giving you time to prepare for single engine flight and not have to recover from a spin. You pull the throttle back then advance it again to throttle up the live engine. I found this to be an asset on my F7. You can get it at Magnum RC.
Old 01-11-2013, 11:23 AM
  #2078  
airraptor
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Default RE: KMP F-7F Tigercat

I plan to go with the RotoMoto 35cc four strokes but if budget doesnt allow the the DLE 35 will go in there. I have been in the hobby for a little bit and I am not scared to modifiy things to fit. Plus who says I will use the stock muffler...... maybe a header with a canister with front exit connected exhaust tubes to "exhaust" in the stock location..

I will design the plane so that all control horn will be internal. I am thinking of selling the ESM electric gear and getting the Sierra gear with brakes and working gear doors.
Old 01-11-2013, 04:22 PM
  #2079  
Ron McGrath
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Default RE: KMP F-7F Tigercat

Here is an article on the build of my tigercat that talks about how the ESC's were set up. 2012 was year #4 with the Tigercat. And other than some batteries connector issues the power system has worked flawlessly!

http://www.rcuniverse.com/magazine/a...rticle_id=1140
Old 01-12-2013, 06:35 AM
  #2080  
ysolomon
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Default RE: KMP F-7F Tigercat

Ron,

I understand from this that the ESCs were in the nacelles. Is that correct? I assume that the two blocks on top of the wing center with the cooling fans are the BECs? You also mention 10AH battery, but if I understand correctly, those were actually two 6S 5AH batteries in series?

You have a beautiful model! Is it still flying?

Yoram.
Old 01-12-2013, 07:10 AM
  #2081  
Ron McGrath
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Default RE: KMP F-7F Tigercat

The battery is a 10s 2p 10 amp hr one of the packs is 2- 3s and 1 4s the other is 2- 5s one 3s pack slides under the wing in the bottom of the fuselage the rest of the packs go under the front of the canopy in the fuselage. My Tiger cat is still in service and I hope to get it out to fly in 2013.
Old 01-12-2013, 11:11 AM
  #2082  
Dangaras
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Default RE: KMP F-7F Tigercat

Yoram,

looks like Ron use two 10 cell, 5000 mAh (where smaller x-cell, 5000 packs were combined to give 10 cells) packs in parallell. The blocks on the wing are the power distribution devices (a fancy BEC). I don't know where the ESCs are, I cant see them in the build.
Old 01-12-2013, 03:28 PM
  #2083  
Ron McGrath
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Default RE: KMP F-7F Tigercat

The esc's are in the cowls.
Old 01-27-2013, 08:04 AM
  #2084  
Eddie P
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Default RE: KMP F-7F Tigercat

This is a really big thread! I love this plane, and the ESM one looks to be a really perfect size for it while getting most of it right.

Does anyone have experience flying this model using two Eflite 110's or Tacon Bigfoot 110's on 8s? It would seem by my calculations a weight savings of at least 4 pounds could be had with the lower power, but you could still be at 3600 amps total without asking nearly too much from those motors. You'd have to fly more at higher power for aerobatics and such but it might be a little more civilized on a short field or paved runways at that lower weight. Now I have zero experience in this model I'm just asking, sine this one has been on and off on my short list to build in the last few years and I'm looking a little more seriously at it now.
Old 01-27-2013, 08:19 AM
  #2085  
Dangaras
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Default RE: KMP F-7F Tigercat

Not happening. On 8 cells both motors will only give you 2280W max and at 26lb (with you planned weight savings) that gives you less than 100w/lb..
Old 01-27-2013, 10:03 AM
  #2086  
Eddie P
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Default RE: KMP F-7F Tigercat

Thanks for the insight. What you say would only be true of one was locked into one - and only one - prop choice. But we can easily alter the prop size and blade count to up the amps all day long - up to the limit of the motor. The major caveat with be motor efficiency within a few percentage points and of course prop pitch speed depending on prop chosen.

Just looking at P-Calc on line and an Eflite110 motor, with a 16X10 two bladed props you'd get nearly 3400 watts total, 31.25 pounds of thrust, a prop pitch speed of 75mph and a miserly (well within range) amp draw of just 57 amps per motor using 8s. (130 watts per pound) A little playing around here and there and it would be simple to get more out of the system with a prop choice.

I've got a power 110 in a single engine warbird and it will put out a whole lot more power than 1100 watts (or 2200 watts with a twin)!! More like 1800 watts without sweating so much in a single. I have motors a half the size of this motor putting out more than 1000 watts. I'm not saying this is a good setup for the F-7F, but I know the 110's can put out a lot of power - just not sure if it's the kind of power the F-7F needs. I think I've always over powered everything I've built in true American fashion but I was a little interested if anyone out there had done a lighter weight ESM F-7F.

With the wing being stubby and the profile of the nacelles being stubby and fat, maybe over powering this bad boy is the way to go. Thanks though, it helps to know what you guys are thinking. Seems like the power 160 would be the basic choice most are using? Anyone using the 110 size motors?
Old 01-27-2013, 01:13 PM
  #2087  
Dangaras
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Default RE: KMP F-7F Tigercat

I used e-calc , 16*10*3, 10 cells, 5000mAh, tacon 160s & that combination delivers 3900W.

On 8 cells there just wasn't enough power for this model. It needs a higher power level to fly well.

I already fly a large invader and initially it was underpowered and it was very taxing to fly. I went from 12*6*3 to 13*8*3 and upgraded motor power by 10%. What a difference it made!

If you want to fly with that 110 & 6 cell setup you might want to buy spare parts now.
Old 01-27-2013, 02:22 PM
  #2088  
Eddie P
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Default RE: KMP F-7F Tigercat

I see, this is the problem, you think I'm talking 6 cells. No, that's not the case, the Power 160 won't really even taxi fast on 6 cells, and the power 110 would fly at about stall speed. I'm currently flying a single engine warbird on the Eflite Power110, it's a good 1600 watt motor without even propping up to the point of getting warm and an 80mph prop pitch speed setup giving about 14 pounds of thrust on 8 or 10 cells, 10 cells being a little more efficient and a tad better overall.

The Power 160 is not designed for 8 cells, the Kv is too low so the numbers you ran on p calc don't apply to a 110 at 8s, they just apply to the 160 in a low voltage setup (low voltage for the 160's kv). The power 110's kv is higher so it opens up 8 cell and higher performance on 10 cell options for lighter setups. It can't take as much ultimate amp load due to the lighter weight but then again 3600 watts is plenty capable with two power 110's.

The above is just basic electric talk though. I'm not challenging you to what the F7F needs as far as power (watts), thrust, and prop pitch speed. I really haven't a clue as to how piggy this model is, that's why I'm asking. Maybe it's a better question to leave the motor "make and model" out and just talk wattage, efficiency, pitch speed and thrust for performance seen at the field. That would be more objective as far as pure F-7F questions.

Have fun flying these, they look great guys.
Old 01-27-2013, 03:24 PM
  #2089  
Streetfuz
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Default RE: KMP F-7F Tigercat

Doesn't anyone build with nitro or gas anymore? I have a 3rd Gen F7F Tigercat Kondor plane, everything is sheeted or cast (One of the last ones shipped before EMS took over) all I see are EP's?


TOM
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Old 01-27-2013, 03:53 PM
  #2090  
Dangaras
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Default RE: KMP F-7F Tigercat

Right, I did not run the calc with a power 10. But be careful, a 110 might get you to the limit on 8 cells and that could make flying hairy!
Old 01-27-2013, 03:58 PM
  #2091  
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Default RE: KMP F-7F Tigercat

KMP was always EMS, just did not want to use the EMS brand.

E-power is it. Wet fuel just does nit fly with me. Too nasty, noxious and noisy.
Old 01-27-2013, 05:19 PM
  #2092  
airraptor
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Default RE: KMP F-7F Tigercat

I ordered DLE 35RA's for mine and will run scale 18x10 3 blade props...
Old 01-27-2013, 05:45 PM
  #2093  
Dangaras
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Default RE: KMP F-7F Tigercat

Which 18*10*3?
Old 01-27-2013, 10:22 PM
  #2094  
ramboman
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Default RE: KMP F-7F Tigercat

Another "110" equivalent...
Due to weight constraints I had to lower the a123 cell count on my Taylorcraft 1/4.
I selected a Hacker A60-6xs designed for 6s LiPo, but running under 7s2s a113.
Mith a CC ICE 100 running at 98A under 20V under max load, you compute...
Flying 8 to 12 min cool. Reloaded in place in 15 min.
Old 01-29-2013, 06:00 PM
  #2095  
ascforithobbies
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Default RE: KMP F-7F Tigercat

Im building a ESM all composite Tigercat with a pair of 23cc gas engines,hyd brakes,E-retracts first thing I did was to remove the bigboss man graphics mine gonna be (Here Kity Kity) 
Old 01-29-2013, 06:16 PM
  #2096  
flytaildragger
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Default RE: KMP F-7F Tigercat

My understanding was that the graphics were painted over... How did you remove the graphics without damaging the paint if you would be kind to share.. and a pic would be nice... Here Kitty is also my fav.
Old 01-29-2013, 07:03 PM
  #2097  
ascforithobbies
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Default RE: KMP F-7F Tigercat

The chineses clear coat is very thin, so 600 grit wet/dry a little rubbing compound and a air buffer and the decals came off without damaging the paint. After removing the graphic, then off to have new vinyl graphic cut to what i wanted and i just bought a automotive clear was very simple to do.
Old 01-29-2013, 10:19 PM
  #2098  
airraptor
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Default RE: KMP F-7F Tigercat

http://www.troybuiltmodels.com/items...-3BYSCALE.html

This prop with around 1/4" of the tip to square it up.
Old 01-30-2013, 01:17 AM
  #2099  
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Default RE: KMP F-7F Tigercat


ORIGINAL: Streetfuz

Doesn't anyone build with nitro or gas anymore? I have a 3rd Gen F7F Tigercat Kondor plane, everything is sheeted or cast (One of the last ones shipped before EMS took over) all I see are EP's?


TOM
Streetfuz

Hi Tom,

Of cource there are nitro/gas flyers :-)......No electro for me...to quiet....I like the sound of 2 fuel engines.
I am stil building on my piper twin comanche who is powered with 2 saito twins......oh man....what a sound. :-)

Kor
Old 01-30-2013, 05:18 AM
  #2100  
Dangaras
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Default RE: KMP F-7F Tigercat

Very nice! Too bad my wallet is empty right now. Maybe after tax season.... I will have to drool over them for now,,,,

Thanx..
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