Combat Electric vx Glow Combat - Page 2 - RC Groups
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Oct 05, 2004, 08:34 PM
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sheepy's Avatar
At the typical RCCA or AMA meet, you could probably get by with two packs, but three would be better. When I flew in Iowa for five rounds, I would have had no problems making heats if the Himaxx's would have held up. I had 3 power sources:
1 tanic 3100(3s2p 1550's)
2 tanic 1700 3s1p used in parallel
1 irate 2600 3s1p
The problem I ran into was that the himaxx's were destroyed or lost in the first two heats, and the only other motor left required a 6s pack to be competetive which meant I missed the last round because I couldn't turn around the 2 1700 packs in time.
Providing everything was compatible, three packs would work great. I had an Astro 109 and a Hobbico MKII for charging. That could have kept me going continuously if the motors would have held up.
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Oct 06, 2004, 05:31 AM
310mph Kolibri T25 Swist
henke's Avatar
lol yeah, problem is not flight time or charging but in flight damage...

after some 5min I really was gettign the speed up, the glowguys has little fuel left and was loosing power in the turns, and my TP pack was getting the heat up and delvierd much power... then I flew the tail of a Thunderbolt and crashed.

and a large pic of the P-47

Oct 06, 2004, 09:28 AM
Does anyone hear a cat?
headless's Avatar
I don't fly in competitions; it's an informal thing the guys at the club do. I would rather not have a plane capable at all than spend hundreds on a setup then have to sit there watching them fly for hours while i charge... would simply underscore the cost/inadequecy of the situation.
Oct 06, 2004, 03:17 PM
Registered User
I have made a wing for combat which I am at the moment making a mould so they can be made from fibre glass the prototype was made from epp and 50 mm drain pipe but epp is very hard to get in the UK.
I have flown it with a Axi 2820/10 and kokam 2000 15 3s1p pack and it gets quite a move on and it will not stall even with full up elevator it just makes a wave motion. I have flown it in wind which even the members of the club with zagi's could not fly.
It is very tough so far it has only broke engine mounts the wing and drain pipe have survived some pretty nasty bangs.
Last edited by paulkcrane; Oct 06, 2004 at 03:20 PM.
Oct 06, 2004, 08:25 PM
Registered User
sheepy's Avatar
Do you have more details on that ship? rpm, duration, speed, comparisons to slimers, auw, wingspan, wing area, prop, batts?
Oct 07, 2004, 12:39 AM
Registered User
This is a prototype and it has been changed quite alot so it is heavy due to the amount of glue used to keep altering it. Life started off with a swept back wing but now has a forward swept wing.
The motor mount can be swapped with removing 4 screws and another motor mount fitted.
I have tried a Axi 2212/20 and MPJ 25/30-20 with 3-1 gearbox both with 9*6 folder and with etec 1200 3s2p it will fly for over 10 mins at full throttle.
With the Axi 2820/10 it really starts to move using 11*7.5 folder and kokam 2000 15c 3s2p with about the same flight time but it does feel heavier to fly.
More details to follow
Oct 09, 2004, 11:23 AM
Registered User
I have put the wings details into Motocalc

MotOpinion - DrainPipe
250ft above Sea Level, 29.92inHg, 68F

Motor: Model Motors AXI AC2820/10; 1100rpm/V; 2.5A no-load; 0.042 Ohms.
Battery: Kokam 2000; 3 series x 2 parallel cells; 2000mAh @ 3.7V; 0.012 Ohms/cell.
Speed Control: Castle Creations Phoenix 60; 0.0012 Ohms; High rate.
Drive System: Graupner 11*7.5 Folding Prop; 11x7.5 (Pconst=1.18; Tconst=0.995) direct drive.
Airframe: Drain Pipe;; 39.7oz; 11.7oz/sq.ft; Cd=0.044; Cl=0.36; Clopt=0.49; Clmax=1.03.
Stats: 160 W/lb in; 107 W/lb out; 18mph stall; 25mph opt @ 41% (72:55, 95F); 30mph level @ 47% (56:40, 99F); 2136ft/min @ 73.4; -253ft/min @ -6.5.

Power System Notes:

The full-throttle motor current at the best lift-to-drag ratio airspeed (38.3A) falls between the motor's maximum efficiency current (18.3A) and its current at theoretical maximum output (68.4A), thus making effective use of the motor.

Possible Aerodynamic Problems:

The static pitch speed (58mph) is greater than 3 times the stall speed (18mph), which might make take-off or hand launching difficult, and is inefficient in flight unless very high speeds are intended.
Pitch speed can be decreased by using a lower pitched and/or larger diameter propeller, a higher gear ratio, a lower cell count, or some combination of these methods.

Aerodynamic Notes:

With a wing loading of 11.7oz/sq.ft, a model of this size will have very sedate flying characteristics. It will be suitable for relaxed flying, in calm or very light wind conditions.
The static thrust (50.3oz) to weight (39.7oz) ratio is 1.27:1, which will result in extremely short take-off runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and vertical climb-outs. This model will probably be able to perform a hover or torque roll.
At the best lift-to-drag ratio airspeed, the excess-thrust (35.3oz) to weight (39.7oz) ratio is 0.89:1, which will give very steep climbs and incredible acceleration. This model can easily do consecutive loops, and has sufficient in-flight thrust for any aerobatic maneuver.

With the Axi 2820/10 I would think it would be a match for a glow plane but as I fly at a electric only site I have not been able to compare.
I will post some more photos soon
Last edited by paulkcrane; Oct 10, 2004 at 05:20 AM.
Oct 11, 2004, 12:46 AM
Registered User
Some more photos
In the photos it has a MPjet 25/30/20 with 3-1 gearbox I use this most of the time because it gives good duration but would not be suitable to use in combat as the gearbox would break easily and it wouldn't be fast enough.
The motor mount unscrews and it only takes about 2 mins to change motor the drain pipe is held on with 3 tie raps to the wing and it only takes about 2 mins to change that so it doesn't take long to repair although I haven't managed to break the pipe yet its is really tough.

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