SMALL - espritmodel.com SMALL - Telemetry SMALL - Radio
Reply
Thread Tools
Old Jul 13, 2003, 02:26 PM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
props n power for GWS spit ?

hi all, been reading and reading and reading and learning and learning and learning, all at the EZONE.

i am eagerly awaiting the arrival of my gws spit and have a few
questions, if you don't mind.

the spitfire on the bus right now is the prepainted green model,
i'm not sure if this is the 350 or the 300 motor.

i plan to run this bird on two sony ( 2 cell per pack ) 1350 mah lithium batteries. will this be enough juice ? will i need to go
with 3 cells per pack ?
i also have some NiMh batteries that came out of an aerobird.
they are a funny size, fatter than aa's, but about 2/3rds the length. they are 7 cell, 900 mah, 3x3x1 configuration.

i have been flying a pico stick for fun with these 1350 sonys
with flight times of 45 minutes. i noticed that by changing from
the stock 10X47 gws prop to an APC 10X7 prop the performance
was oustanding, and the flight times were actually longer.
my friend and i have been combatting with the sticks and having
an absolute blast. lost mine yesterday after he cut my tail feathers off. pretty spectacular crash ! there is NOTHING left.
i would like to use an APC on the spit, now i'm wondering which one will be the best match. or is the GWS prop pretty good ?
i think the GWS prop that comes with the spit is a 10X7 ??
i am thinking that the same 10X7 apc will be a better performer
but wanted your experience to know before i crash due to under
powering, or cooking an esc, or motor.

i've been admiring the other spits on here, well done everybody !

sounds like this one may be a tuff one to balance ?

i'll be flying 3 channel, no rudder. any advice here ?

thanks in advance, i can't wait !
spithungry is offline Find More Posts by spithungry
Reply With Quote
Sign up now
to remove ads between posts
Old Jul 14, 2003, 09:44 AM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
i tried the sony 1350 lithium ions ( 2s1p ) today with a speed 380, or whatever it is in an aerobird. they shut down, got hot, well, warm anyways. i believe the built in curcuit protection within the batteries activated. if i glided for a minute the power came back. ( this was on a lite stick, with a motor strapped to the front, direct drive, with a 6.4 prop.
this could be the bec cutting in, or it could be the battery's self protection.
the spit has a 300 on the nose, so it looks like the current capability of these batteries will not be enough.
from what i have been reading, making a 3s1p pack is not the answer, this will give me plenty of voltage, but the current will still be limited to the C of the batteries. looks like my best bet would be to build 2s2p packs ? this also worries me because it keeps voltage at 7.2, but only doubles the current to 6 or 7 amps, probably still not enough. the other solution is to build 3s2p pack, but that is going to be ALOT of weight.
i weighed a two cell pack of these sony's, they weigh in at 80 grams. 6 of these in the front of the spit will be 240 grams.
is this too much ?
looks like i may be using NIMh after all.......
spithungry is offline Find More Posts by spithungry
Reply With Quote
Old Jul 14, 2003, 10:08 AM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
i tried the sony 1350 lithium ions ( 2s1p ) today with a speed 380, or whatever it is in an aerobird. they shut down, got hot, well, warm anyways. i believe the built in curcuit protection within the batteries activated. if i glided for a minute the power came back. ( this was on a lite stick, with a motor strapped to the front, direct drive, with a 6.4 prop.
this could be the bec cutting in, or it could be the battery's self protection.
the spit has a 300 on the nose, so it looks like the current capability of these batteries will not be enough.
from what i have been reading, making a 3s1p pack is not the answer, this will give me plenty of voltage, but the current will still be limited to the C of the batteries. looks like my best bet would be to build 2s2p packs ? this also worries me because it keeps voltage at 7.2, but only doubles the current to 6 or 7 amps, probably still not enough. the other solution is to build 3s2p pack, but that is going to be ALOT of weight.
i weighed a two cell pack of these sony's, they weigh in at 80 grams. 6 of these in the front of the spit will be 240 grams.
is this too much ?
looks like i may be using NIMh after all.......
spithungry is offline Find More Posts by spithungry
Reply With Quote
Old Jul 14, 2003, 10:09 AM
Lookin' Good. Real Good.
larsy87's Avatar
London, Canada
Joined Aug 2002
3,979 Posts
What kind of Nimhs do you have? I plan on using a 7 cell 350 MaH 2/3AA battery and a 7 cell 600 Mah AA battery. I know the 350 won't last long, but it'll give me 3-4 minutes of flight time. That's about the average flight times I fly anyways.

I am not an expert on Lithium Ions, but it sounds like your batteries can't take the AMP draw, so they may be shutting down. I don't know about adding batteries to it. SOmeone needs to help you there.

Good Luck

Cam
larsy87 is offline Find More Posts by larsy87
Reply With Quote
Old Jul 14, 2003, 10:19 AM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
yeah, i'm finding that the sony lithium ions have a discharge rate of about the 3 amp maximum. two of these fly my pico stick FOREVER !
i am strongly leaning towards making 3/ 2 cell packs of the lithiums in parallel. this " should " be good for aprox 9 amps, but i will still suffer from a gutless spit, being that the volatge is low, and i would like to see an 8 cell voltage for a bit of performance.
at least the flight times should be long.
( always a trade off isn't there ? )

after being in the air for sooooo many minutes on the pico 6 minute flight times are gonna seem extremely short to me now if i go with the NiMh's.

i haven't the cash for the really nice lithium polys right now
( big pouty face here.....), i think that they would relly be the way to go, but for now i hafta improvise.

thanks for the response ! i can't wait to pick this thing up, build it, make it pretty, and chuck it into the sky ! ( will be flying the pico while the glue dries though : )
spithungry is offline Find More Posts by spithungry
Reply With Quote
Old Jul 14, 2003, 10:22 AM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
oh, BTW, the NiMh's are a funny size, 7 cell packs, 900 Mah,
out of a firebird kinda airplane. they look like fat aa's, about two thirds the lenght of a aa. they are stacked 3x3x1.
good performance out of these, just heeeavey.
spithungry is offline Find More Posts by spithungry
Reply With Quote
Old Jul 14, 2003, 11:16 AM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
Mongoose,
will you be flying your spit with 3 or 4 channels ?
have you had other gws warbirds ?
i know i've seen you post here many times, but can't remember
what about now ( information overload from all the reading here at e-zone ).
spithungry is offline Find More Posts by spithungry
Reply With Quote
Old Jul 14, 2003, 11:29 AM
Registered User
Ralph A. D'Amelio's Avatar
United States, MA, Chelmsford
Joined Jul 2000
3,425 Posts
Get a MPI AC 25/35 Bl for $49 and 8 720 Sanyo nimh. I fly this in my 109 nd now my Spit solid 7 minutes of great all out flying. Using an APC 9x6 at about 7 amps. The GWS 9x7 prop makes some funny noises in a high speed dive
Ralph A. D'Amelio is offline Find More Posts by Ralph A. D'Amelio
Reply With Quote
Old Jul 14, 2003, 11:45 AM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
hmmmmmmmmm........
guess that means i will need a brushless esc too ?

those apc's are the greatest aren't they ! my pico wails with
an apc 10/7 on the front of it.

and yeah, i figured there'd be good performance with an 8 cell set up. only 7 amps eh ? maybe my sonys WILL handle this...
how many grams are the batteries that you are using now ?
spithungry is offline Find More Posts by spithungry
Reply With Quote
Old Jul 14, 2003, 12:13 PM
Lookin' Good. Real Good.
larsy87's Avatar
London, Canada
Joined Aug 2002
3,979 Posts
I have GWS Mustag, as well, which is on Aileron and Elevator only. I find I prefer bank and yank style better than those scale turns!!!

My Spitfire will be with 4 channels, cuz its just too nice of a plane to be racked around the skies fun fly like.

Yeah, I'm contradicting myself...but I don't care

Yes, if you buy a Brushless motor, you will need a Brushless ESC, or else it will go not working or something like that.

Ralph's batteries are similar to mine I think, and mine weigh about 4 ounces, so his would be similar or a little more due to the extra cell.

You'll get that Spit tricked out right!

Cam
larsy87 is offline Find More Posts by larsy87
Reply With Quote
Old Jul 14, 2003, 01:34 PM
Registered User
Ralph A. D'Amelio's Avatar
United States, MA, Chelmsford
Joined Jul 2000
3,425 Posts
Cam got it exactly right. They are some great videos on this site with lipos http://www.e-flightline.com/
Ralph A. D'Amelio is offline Find More Posts by Ralph A. D'Amelio
Reply With Quote
Old Jul 15, 2003, 12:13 AM
no strings attached
spithungry's Avatar
the great white north
Joined Jul 2003
239 Posts
yes, i've been to that site and watched ALL the videos. sure is nice of people to share all the great fun and knowledge.
i love they way the spit seems to be able to just " dog " around, and then look so authentic when doing a high speed low pass.
i'm gonna do LOTS of those !

just finished building my second pico stick this evening.
did some wing brace mods for those " high " g manouvers.
( or should i say " manures " )

i'm still thinking about what to do with these lithiums. guess i won't be happy till i see the right set up fly.

i can't beleve i used to fly 60 size pattern. this electric stuff has got me HOOKED but good. so easey, so clean, so " do anywhere ". the school is a block away from the house. a short drive gets me to a very nice school field with a track that i just love for calm days and practising my touch n goes, or just seeing how far i can drag the antenna along the ground behind me.
what a BLAST.
spithungry is offline Find More Posts by spithungry
Reply With Quote
Old Jul 15, 2003, 04:29 AM
Houng-wen Lin
GWS4CEO's Avatar
Shijr, Taiwan. DungGwan, China. City of Industry, California.
Joined Sep 2001
19,445 Posts
Welcome to the world of E-fly.

Wish GWS will let you enjoy a lot of fun with us.

The new mini F3A Formosa is comming! should be something for a pattern flyer's choice.

http://www.gws.com.tw/english/product/airfly/f3a.htm

GWS4CEO is offline Find More Posts by GWS4CEO
Reply With Quote
Old Jul 15, 2003, 06:22 AM
Registered User
kensp's Avatar
Darwin Australia
Joined May 2002
6,960 Posts
I am currently building my Spitfire. I am weighing it as I do each step. At the moment it is just to the stage where it is ready for painting and it weighs just less than 5.7 oz. This promises to give an AUW, ready for flight, of just 12-oz when using an E-Tech 1200mAh 1S1P lithium battery. (These batteries only weigh 1.85 oz). I can thoroughly recommend these batteries. I currently have 308 minutes of running on mine and have had no problems. In my GWS Zero, which weighs 13 oz, I get a run time of 14 minutes when using a GWS 9x7 and 10 minutes when using a GWS 10x8. The Spitfire being lighter promises to fly even longer. These times are WOT. The E-Tech will supply all the power that the GWS 300C-CS motor/gearbox can handle.

Photo progress so far.

Ken
kensp is offline Find More Posts by kensp
Reply With Quote
Old Jul 15, 2003, 07:52 AM
Lookin' Good. Real Good.
larsy87's Avatar
London, Canada
Joined Aug 2002
3,979 Posts
TWELVE OUNCES!!!! That's realllll Light!! Mine weighs about the same, 11 ounces painted, but with my Nicds, it weighs 15 ounces. Damn, I need Lipolys.

Its looking good!!!

Cam
larsy87 is offline Find More Posts by larsy87
Last edited by larsy87; Jul 15, 2003 at 07:55 AM.
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Brushlees power for gws beaver MAKO-6 Foamies (Kits) 4 Sep 17, 2005 07:56 PM
EPS 400 power for GWS Corsair? Brownwood Power Systems 2 Jul 28, 2005 05:40 PM
Batts for the GWS Spit Auger Din Parkflyers 0 Aug 19, 2003 08:23 AM
props n power for gws spit spithungry Power Systems 0 Jul 14, 2003 05:52 AM
Nicad power for GWS Zero Zeroaltitude Foamies (Kits) 8 Oct 06, 2002 04:33 AM