Mudelismifoorum

Leidsin omaarust sobiva mootori Kyosho Pitts Specialile(el.versioon).
1300W ja ka muud näitajad ok.
Küsimus tekkis seoses reguga,on olemas regu koos BEC ja ilma.
Kuna vatuvõtja ja servode toide oleks soovitav panna eraldi ,siis BEC olemasolu vist pole oluline.
Link: http://www.modellhobby.de/Engines-and-e ... =109&c=109

Samas BEC varustatud reg. võimaldaks masina vatuvõtja aku võrra kergemaks muuta,kuigi teisalt jälle lennuohutus ehk kannataks !?

Kui eraldi toite paned siis võid jah vabalt võtta regu millel BEC ei ole.

Kui osta BECiga regu, siis lõpuks saab alati regulaatoril punase juhtme vastuvõtja pistikust lahti ühendada ja eraldi vastuvõtjaakut kasutada. BECi olemasolu ei tohiks regulaatori kaalu oluliselt tõsta, paar grammi vast.

Tavaline BEC on enamikel regudel küljes, mis mõeldud töötama väikese akupinge pealt (kuni 4 LiPo näiteks). Ilma BEC'ita/OPTO (odavam) või UBEC'iga (kallim) valik on nende regude puhul, mis toetavad kõrget akupinget (näiteks alates 4-5 ja rohkem LiPo-t).

Proovisin motocalciga,kõik parameetrid pole veel ideaalselt õiged aga abiks oli ikkagi

MotOpinion - Pitts 2
50m above Sea Level, 101,3kPa, 14,7°C

Motor: Dymond 5055 C; 580rpm/V; 2A no-load; 0,043 Ohms.
Battery: Kokam 3200SHD (20C); 5 cells; 4000mAh @ 3,7V; 0,008 Ohms/cell.
Speed Control: Generic Brushless ESC; 0,006 Ohms; High rate.
Drive System: 12x8; 12x8 (Pconst=1,31; Tconst=0,95) direct drive.
Airframe: Pitts 2; 43dm²; 2601g; 60,5g/dm²; Cd=0,039; Cl=0,16; Clopt=0,35; Clmax=0,89.
Stats: 238 W/kg in; 196 W/kg out; 10,8m/s stall; 17,2m/s opt @ 67% (27:46, 38°C); 25,4m/s level @ 94% (13:49, 51°C); 7,55m/s @ 26°; -2,72m/s @ -9,1°.

Possible Power System Problems:

The estimated steady-state still-air battery temperature at the hands-off cruise airspeed and throttle setting (greater than 95°C) is higher than the suggested maximum temperature for this cell type (50°C). This could result in battery pack damage unless adequate cooling airflow is provided and/or run times are kept short. A lower current would also decrease the battery temperature.
Current can be decreased by using fewer cells, a smaller diameter or lower pitched propeller, a higher gear ratio, or some combination of these methods.

Power System Notes:

The full-throttle motor current at the best lift-to-drag ratio airspeed (34,2A) falls approximately between the motor's maximum efficiency current (28,1A) and its current at theoretical maximum output (197,8A), thus making effective use of the motor.
The voltage (16,8V) exceeds 12V. Be sure the speed control is rated for at least the number of cells specified above.

Aerodynamic Notes:

The static pitch speed (28,8m/s) is within the range of approximately 2,5 to 3 times the model's stall speed (10,8m/s), which is considered ideal for good performance.
With a wing loading of 60,5g/dm², a model of this size will have trainer-like flying characteristics. It would make an ideal trainer, for use in calm to light wind conditions.
The static thrust (2307g) to weight (2601g) ratio is 0,887:1, which will result in very short take-off runs, no difficulty taking off from grass surfaces (assuming sufficiently large wheels), and steep climb-outs.
At the best lift-to-drag ratio airspeed, the excess-thrust (1203g) to weight (2601g) ratio is 0,462:1, which will give steep climbs and excellent acceleration. This model should be able to do consecutive loops, and has sufficient in-flight thrust for almost any aerobatic maneuver.

General Notes:

This analysis is based on calculations that take motor heating effects into account.
These calculations are based on mathematical models that may not account for all limitations of the components used. Always consult the power system component manufacturers to ensure that no limits (current, rpm, etc.) are being exceeded.

Seal tekstis väidetakse, et akule tehakse liiga. 5 järjestikuse aku ja 11x7 propiga mingeid hoiatusi ei tekkinud ja on äkki parem? See eeldab aga muidugi laadijat ja balanserit, mis 5 akuga hakkama saaks.

Ervin2 wrote:
Current can be decreased by using fewer cells...

Eee, kas nagu vastupidi ei ole?
Et kätte saada sama võimsust, siis suurem purkide arv vähendab ikka voolu.

Mis ESCi puututub siis mina võtaksin opto- häite kindlam, kuna juhtmed on optiliselt eraldatud.

tarts wrote:

Ervin2 wrote:
Current can be decreased by using fewer cells...

Eee, kas nagu vastupidi ei ole?
Et kätte saada sama võimsust, siis suurem purkide arv vähendab ikka voolu.

Mis ESCi puututub siis mina võtaksin opto- häite kindlam, kuna juhtmed on optiliselt eraldatud.

Vähendades purkide arvu väheneb sama propiga lastes vool. Muidugi võimsus ka.