Author Topic: Svecice  (Read 7904 times)

Offline Goran

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Svecice
« on: July 30, 2008, 09:15:03 PM »
Evo pitanja za iskusne modelare.

Kako odabrati svecicu za motor.
U pitanju je Kometa od 4.7 kubika.
Na stanju smo imali neke "cne" i neke "bele" :-) i skoro sve su izgorele za krace ili duze vreme.
Desilo se cak da za jedan let crknu 3 svecice (nove ne koriscene).

Da li neko zna zasto se to desilo i kako preduprediti crkavanje svecica.
Da li motor rastrese svecicu ili je neodgovarajuce gorivo ili njena toplotna vrednost je kljuc?

Molim za savet.

Pozdrav Goran

Offline Goran

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Re: Svecice
« Reply #1 on: August 06, 2008, 11:26:10 PM »
Priznajem da je pitanje izgleda bilo tesko.

Mogu li na popravni?

Kako odrediti kakav tip svecice je potreban za koji motor.
Pominju se neke hladne, srednje tople, tople itd.

U pitanju su Vebra male kubikaze, Kometa 4.8 kubika, Raduga 7.5 kubika i OS max FX46 za koji doduse pise da mu treba neka A3 ili A5 svecica. Ali sta sa ostalima?

Da li postoji neko pravilo u izboru svecica?

Pozdrav Goran

Offline SABURO

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Re: Svecice
« Reply #2 on: August 07, 2008, 01:04:54 AM »
ovako...

na mom motoru mvvs 6.5 ccm, koristim os A3 svecicu, ona pasuje i za 7.5 ccm, dok za motore od 8.5-10 ccm treba stavljati A5 itd...
veci motor, veca kolicina goriva koja hladi, veca toplotna vrednost svecica...

Evo pitanja za iskusne modelare.


Desilo se cak da za jedan let crknu 3 svecice (nove ne koriscene).

Da li neko zna zasto se to desilo i kako preduprediti crkavanje svecica.
Da li motor rastrese svecicu ili je neodgovarajuce gorivo ili njena toplotna vrednost je kljuc?

Molim za savet.

Pozdrav Goran

Inace u poslednje vreme mi se desavala slicna stvar, u roku od mesec dana promenio sam 3-4 svecice, na kraju se ispostavilo da je motor rastresao ( vibracije ) svecice i samo je bilo pitanje vremena kad ce vlakno da pukne, tj. crkne svecica!
Razlog zbog cega mi se sve to izdesavalo je u lezao u lezajevima kroz koje prolazi osovinica ( radilica ), jednostavno dotrajali su i stvorio se debalans koji je prouzrokovao vibracije...

e sad moze biti i do samog stelovanja motora, tj. to dosta zavisi od vremena ( spoljasnja temperatura ) i kako model aviona forsiras tokom leta...

u sustini predlozio bih ti da stavis A3 svecicu, inace ima i neka f serija OS-ovih svecica koje pasuju i na cetvorotaktne i dvotaktne motore ( cena je oko 12-13 e komad ), mislim da bi ti one najbolje pasovale, btw koje gorivo koristis?

Nikola | rcfly.in.rs


Offline Goran

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Re: Svecice
« Reply #3 on: August 07, 2008, 09:41:07 AM »
"veci motor, veca kolicina goriva koja hladi, veca toplotna vrednost svecica..."

Hvala to sam hteo da saznam. Dakle u tome je caka.

Juce smo bili na aerodromu sa Taxi-jem i zamenjenim motorom.
Do sada je bila Kometa (nova) ali sa njom nije moglo nikako da se usaglasi mali i veliki gas.
Najgore je bilo to da motor lepo radi, ali kada ga bacis on izgubi gorivo i motor se ugasi na poletanju. Tj nekad se ugasi a nekad ne.

Sada smo stavili neki stari pocrneli OS-max isto od 4.7 kubika.
E to je ve? pesma. Motor radi kao sat.

Inace za gorivo sam pronasao jeftini izvor metil alkohola, tako da to nije vise uopste problem, a ricinus jos uvek imamo stare zalihe od pre 20 godina. Nitro metan nemamo niti stavljamo.

Pozdrav Goran
P.S. Ovih dana treba da stigne jedrilica Ventus.... :-)


Offline Dejan Dobricki

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Re: Svecice
« Reply #4 on: August 07, 2008, 10:17:29 AM »
pa ovako da se i ja malo ubacim u temu svecice se dele na tople, srednje tople i hladne  sa brojevima 1-3 tople 4 i 5 srednje 6-8 hladne, neki proizvodjaci imaju skalu samo do 6 , sto je veci motor tj zapremina ide se ka hladnim svecicama koje imaju deblju nit i komore u kojoj se nalazi ta nit u svecici je manja pa usled vece kolicine goriva teze gube toplotu isto tako sto vise nitroa to idemo ka hladnijim svecicama jer je ta komora manja i nit deblja pa se usled detonacija nece ostetiti pa onda sto je toplije vreme idemo ka hladnijim svecicama koje usled vece temperature lakse izdrzavaju tu toplotu jer je nit deblja ,isto tako ako letis zimi sa jako hladnom svecicom ona teze ostaje uzarena to se primecuje kada palis motor i kada upali u trenutku kada skines sa nje stipaljku osetno opadne obrtaj lera to ti je znak da imas hladniju svecicu i kada skines napon sa nje ona se za nijansu ohladi i samim tim motor malo spusti obtaje, na sve ovo utice i koja se elisa koristi jer ne vrti isti motor isto sa razlicitim elisama, moja preporuka je da se drzis srednjih i toplih svecica jer ne koristis nitro ali veruj mi da je samo na tebi jer to sve treba da probas i testiras sam ,naj bolje je drzati se proizvodjacevih specifikacija gde on preporucuje tu svecicu , gorivo sa toliko nitroa i ta i ta elisa za koji stil letenja .

ps-ako sam negde pogresio neka me slobodno ispravi

Offline Goran

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Re: Svecice
« Reply #5 on: August 09, 2008, 07:28:02 PM »
Hvala za prave informacije...

Pozdrav Goran

Offline saborp

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Re: Svecice
« Reply #6 on: July 17, 2009, 11:24:43 AM »

Offline Goran

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Re: Svecice
« Reply #7 on: August 01, 2009, 11:07:26 PM »
Odličan link.
Evo šta piše na njemu:

OS Glow Plug Information

# 8 Hot Recommended for most current O.S. (and other) 2-stroke engines
Type F Mildly Hot Special long-reach plug recommended exclusively for O.S (and other) 4-stroke engines
Type RE Hot Special long-reach plug designed exclusively for O.S. Wankel rotary engine
A5 Cold Recommended for most current O.S. (and many other) 2-stroke engines particularly for 1/10th & 1/8th scale off-road car engines
A3 Hot Dependable O.S. quality makes A3 the most durable and longest-lasting glow plug available at an economical price
R5 Very Cold Recommended for high-nitro fuel and high r.p.m. engines, particularly 1/8th track racing car engines
ENYA Glow Plug Information

# 3 Hot All Enya engines such as TV & four cycle engines
# 4 Mildly hot All Enya engines, especially those used with 10%or greater nitromethane fuel
# 5 Medium All Enya engines, especially the .40CX, .45CX and high nitro methane fuel
# 6 Cold High compression engines and high niro methane fuel used in racing.
Fox Glow Plug Information

All 1. 5 Volt Plugs are Dry Cell or Ni-Cad All 2 Volt Plugs are Lead Acid Battery

Standard Short Hot 1.5 Volt, Standard Short Hot 2 Volt
Standard Long Hot 1.5 Volt, Standard Long Hot 2 Volt
Gold STD Long Plug Hot 1.5 Volt, RC Short Mildly Hot 2 Volt
Gold RC Long Hot 1.5 Volt, RC Long Mildly Hot 2 Volt
RC Short Mildly Hot 1.5 Volt
RC Long Mildly Hot 1.5 Volt
Miracle Plug Hot 1.5 Volt
Pro 8 Short Cold 1.5 Volt
Pro 8 Long Cold 1.5 Volt
McCoy Glow Plugs with OS Equivalent

MC-8 Medium Hot #8 (thanks for correction, mvbashers.org)
MC-9 Cold A5, R5 (thanks for correction, mvbashers.org)
MC-50 Hot IDLE BAR - LONG
MC-55 Medium Hot A3, #8
MC-59 Hot
STD ROSSI GLOW PLUGS BI-TURBO GLOW PLUGS (without idle bar) (conical w/o washer)

Rossi Glow Plugs (cold for pattern type work / high nitro fuels, hot for sport / low nitro flying)

R1 Extra hot 0.8 to 2cc RB4 Hot
R2 Hot from 2 to 3.5cc RB5 Medium
R3 Medium from 3.5 to 6cc RB6 Cold
R4 Cold from 6 to 10cc RB7 Extra cold
R5 X-cold for nitro fuel & R/C RB8 Super cold
R6 Cold nitro 10 to 13cc
R7 Cold for nitro 13 to 15cc
R8 Cold for nitro 15 to 30cc GLOW HEAD FOR R15
G1 Hot
R/C GLOW PLUGS

G2 Medium (with idle bar)
G3 Cold nitro 15 to 30%
RC Hot for 2.5 to 6cc
G4 X-cold nitro 30 to 50%
RC Cold for 6 to 15cc
G5 Cold nitro 50% or more
Glow Plug Usage Tips
Your glow plug temperature range is too cold when:

    * The engine power is weak or has weakened from previous levels.
    * The engine slows down considerably or stops after removing the glow plug battery, despite correct adjustment of the needle valve. For example (Enya), if a # 4 plug gives you these problems in your engine, switch to a # 3 plug instead.

Your glow plug temperature range is too hot when:

    * The engine suffers from pre ignition and loss of power.
    * The overall engine running is rough
    * The glow plug filament is broken or collapses frequently.

These are several cures to these problems. We suggest using a fuel with less nitro methane content, using a larger size propeller or using a colder plug than the one currently in use. For example if an Enya # 3 plug gives you these problems in your engines, switch to a # 4 plug.

Model glow plug engines are extremely dependent upon the type and quality of the glow plug used. Enya glow plugs use a platinum alloy coil, which uses a thick diameter wire for long life. The thicker wire coil also eliminates the need for an "idle bar" as found on other brands of glow plugs; idle bars tend to reduce top speed slightly, to achieve a more stable idle speed. Enya's glow plug design insures both good top end speed and stable idle speed.

Enya glow plugs also have a thicker battery contact at the tip of the plug for greater heat dissipation and better electrical contact. Altech Marketing presently stocks glow plug battery cords specifically for Enya glow plugs, which are standard equipment with Enya four-cycle engines. Other glow plug cords usable with Enya glow plugs are available from several other manufacturers.
HOT GLOW PLUGS (for low nitro and FAI fuels)

Enya: # 3
Fox: Miracle, Standard, and R/C Long (2V)
Fireball: Hot (1.2-3.0V), and S-20 R/C Long
Fire Power: F 6 (warm), and F 7 (hot)
K&B: 1 L
McCoy: MC 55 R/C Long, MC 59, and MC 14 (very hot)
O.S. Engines: # 0, # 1, # 5
Rossi: R 1 (extra hot), and R 2
Sonic Tronics: Glowdevil # 300
Thunderbolt: R/C Long
MEDIUM GLOW PLUGS (for 10%-15% nitro fuels)

Enya: # 4 (medium hot), and # 5 (medium cold)
Fireball: Standard (1.2-2.0V)
Fire Power: F 5 (medium), and F 6 (warm)
Fox: R/C Long (1.2-1.5V), and Gold
Hanger 9: Sport Long
McCoy: MC 50, and MC 8
O.S. Engines: # A 3, # 8, # 9, # 7 (with idle bar)
Rossi: Medium, and R-3
Sonic Tronics: Glowdevil Standard
Tower Hobbies: Tower Power Performance plug, and Reg. (w/bar)
COLD GLOW PLUGS (for high nitro; 25% +)

Enya: #6 (cold)
Fireball: Cool (1.2-1.5V)
Fire Power: F 2 (extra cold), F 3 (cold), and F 4 (cool)
Fox: R/C (1.2V), and # 8
K&B: Long & Short high performance nitro plug
O.S. Engines: R-5
Rossi: R 4 (cold), and R 5 (extra cold)
FOUR-STROKE GLOW PLUGS (hot)

Fox: Miracle plug (often used in 2C's W/low nitro)
McCoy: MC 14 (very hot, often used in inverted 4C's)
O.S. Engines: Type F
Sonic Tronics: Glowdevil ST 301/302
IDLE BARS

Idle bar glow plugs came about because some engines were having trouble transitioning from idle to high speed. When the throttle was opened from idle, the incoming air and raw fuel would strike the glow plug's heated coil, cooling it to the point where it would no longer support the combustion process, so the engine would die. To help prevent this, the idle bar was added to the glow plug to serve as a physical shield, helping to keep the coil from cooling off too quickly.

A glow plug with an idle bar will not increase peak RPM (it may even reduce it in some cases), but it may improve the idle with some engines, since it simply helps to keep the plug hot enough to light the fuel. If your having transition problems, you might want to try using a glow plug with an idle bar. Some modelers use idle bar plugs in the winter only, since the glow plug tends to loose heat faster in the colder environment.

Naturally, all of this assumes that you have the low speed mixture adjusted correctly to begin with.
HOT PLUGS

So what is a 'hot' plug, and how does it differ from a 'cold' plug?

Naturally, a hot plug will heat up faster and stay hotter, but that's not the whole story. When discussing this aspect of glow plugs, another very important aspect must be considered, the amount methanol in the fuel. The more methanol we're using (i.e., less oil and less nitro), the hotter the plug we should use. Conversely, the more nitro and/or oil we use, the less methanol we're using, so we use a cool(er) plug. An extreme example would be when using a very high nitro content fuel in a very high RPM engine (a typical ducted fan engine, for example). Here we'd use a very cold plug. For most sport pilots using fuel with just 5-15% nitro, however, a hotter plug would probably do well.

Probably? Yes, trial and error is often the best (and sometimes 'only') way to determine the right glow plug for your application. Most 4C engines need either high nitro or hot plugs to run at their best, since they have combustion strokes only half as often as 2C engines.
RULES OF THUMB TO LIVE BY

    * Use a hot plug with low nitro (less than 24%), and a cold plug with high nitro (more than 25%).
    * If you remove the glow starter from you idling engine, and notice an immediate drop in RPM, you may need a hotter plug or more nitro.
    * If your engine has a tendency to backfire a lot, you may be using a glow plug that's too hot, or you may need fuel with less nitro.
    * Most hot plugs can take up to 2.0 volts starting power without burning up, while most cold plugs prefer 1.2 to 1.5 volts starting power.

Offline sasa

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Re: Svecice
« Reply #8 on: August 23, 2009, 04:15:26 PM »
Imam jedno pitanje.
Naime...imam motor na jedrilici ASP OD 2,5ccm i stoji mi naopako na drzacu to jest svecica mu je dole pa posle pet sest potrosenog rezervoara
toliko nahvata chadju da se motor gasi.
jednu sam vec upropastio cackajuci sa iglom pa otud i moje pitanje...
dakle ...u sta bi mogla da se potopi svecica da se rastvori chadja ili mozda neko ima bolju ideju

POZ...SASA
BOLJE JE DA PLACES STO NISI NA NEBU NEGO DA PLACES STO NISI NA ZEMLJI

PRE NEGO STO PUSTIS JEZIK , PROVERI DA LI SI UKLJUCIO MOZAK

Offline Yu-men

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Re: Svecice
« Reply #9 on: August 23, 2009, 08:21:26 PM »
 ;namig

dakle ...u sta bi mogla da se potopi svecica da se rastvori chadja ili mozda neko ima bolju ideju

POZ...SASA

@ sasa

Probaj sa sprejom za ciscenje oruzja. :mhm

Skoro sam imao problem na autu sa AGR-ventilom (sluzi da deo izduvnih gasova vrati nazad na ponovno sagorevanje) zato sto je od garezi zapusio.
Skinuli smo ventil dobro ga naprskali i ostavili da prenoci, sledece jutro sve izduvali kompresorom i sad radi kao nov.


P.S. ako bude radilo dodjes mi jedno pivo na tri Vasara  :_D

(<--)   pozdrav svima
« Last Edit: August 23, 2009, 08:25:32 PM by Yu-men »
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Offline Dejan Dobricki

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Re: Svecice
« Reply #10 on: August 23, 2009, 09:46:40 PM »
probaj nitro razredjivac a sigurno ce ti pomoci sprej za ciscenje karburatora

http://www.wurth.co.yu/PDF_Auto/A%2005%200005.pdf

ovo skida burazeru sve zivo ne zivo provereno jer sam skidao karbonizaciju sa ventila stim i na kraju ispolirao sa vodeno smirglom ali tebi smirgla nece trebati :_D
« Last Edit: August 23, 2009, 09:48:46 PM by Dejan Dobricki »

Offline GILE

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Re: Svecice
« Reply #11 on: August 24, 2009, 09:59:04 AM »
Koje gorivo koristis kad se stvara karbonizacija na 2,5 ccm
Covek prolazi kroz tri stadijuma znanja u svom zivotu:
1- Misli da sve zna
2- Zna koliko zna
3- Zna koliko nezna (tu sam sad)

Offline sasa

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Re: Svecice
« Reply #12 on: August 24, 2009, 10:22:39 AM »
Koristim metanol sa 20 posto ricinusa ali ninajednom drugom motoru pa ni na ovom se ne stvara chadja kada je svecica okrenuta na gore samo u ovom
slucaju kada motor stoji naopacke a postavio sam ga tako zbog manjeg otpora vazduha na krilu jedrilice
POZ...
BOLJE JE DA PLACES STO NISI NA NEBU NEGO DA PLACES STO NISI NA ZEMLJI

PRE NEGO STO PUSTIS JEZIK , PROVERI DA LI SI UKLJUCIO MOZAK