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Old Jul 05, 2005, 03:30 PM
United Kingdom, Leighton Buzzard
Joined Sep 2004
548 Posts
Can I Run An IPS Motor On 800Mah cells

hi guys

this may sound like a stupid question, but is it ok to run a gws IPS motor on 5 800MAh Ni-Mh cells in serise to give 6volts and will this pack last longer than 5 300MAh Ni-Cd cells in serise?

Thanks MAtt
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Old Jul 05, 2005, 03:45 PM
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vintage1's Avatar
East Anglia, UK
Joined Sep 2002
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Youy can run teh motor, but I seriously doubt the plane will fly...too much weight.

best efficiency would be 10 cells anyway, unless you use the RLC motor..
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Old Jul 05, 2005, 03:48 PM
United Kingdom, Leighton Buzzard
Joined Sep 2004
548 Posts
vintage1 flew her the other day with the nicads it only weighs 5oz but the nicads only last 4mins
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Old Jul 05, 2005, 04:02 PM
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East Anglia, UK
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Go for LIPOS then. And get 45 minutes

I got a very decent 3s pack of 450mA/h cells that should fly easily that long..from weston UK.

You are on a losing wicket with the low voltage heavy metal stuiff. The motors are far more efficient at higher voltages, and you only need about 2A max to fly...if you are flattening 300mAh in 4 minutes you must be pulling over 3A..that will kill an IPS in short order - unless its the RLC motor.

Have a look at www.shaman.co.uk/models/cans/RXC.html

Thats the assembled wisdom of the ezone on IPS running EFFICIENTLY..
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Old Jul 05, 2005, 04:25 PM
United Kingdom, Leighton Buzzard
Joined Sep 2004
548 Posts
I would go for lipos but i realy don't have the money im 15 trying to keep one rc plane flying and paying for microlight lessons at 85 pounds an hour. and lipos need expensive chargers aswell right?

p.s prolly a stupid question, but what the RLc motor?

What would be the cheapest way to get this plane flying for more than 5mins?

please help guys i miss flying my planes

MAtt
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Last edited by littleport2003; Jul 05, 2005 at 04:37 PM.
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Old Jul 05, 2005, 05:57 PM
ooops
StCalvin's Avatar
Dekalb,Illinois
Joined Oct 2003
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All you really need is 6 to 7 cells ( nihms) at around 300 Mah. Depending on the plane you'll get 10 to 15 mins. I fly a 280 motor with 7 cell 300 mah and reguarly get close to 15 mins.
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Old Jul 05, 2005, 06:44 PM
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RLC is a hotter wound IPS motor. Works better on lower voltages.

I only paid 19 quid for my 3s LIPO pack. So its not that bad to go LIPOS on IPS.

Your flight times suggest a non-optimum setup - best double check what gearbox and prop you have..?
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Old Jul 06, 2005, 03:37 AM
United Kingdom, Leighton Buzzard
Joined Sep 2004
548 Posts
vintage1 im 15 where the heck am I gunna get 19quid and then i need to get an expensive charger!
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Old Jul 06, 2005, 04:16 AM
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dunno. Buy some oil futures?
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Old Jul 06, 2005, 04:26 AM
All under control, Grommit!
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United Kingdom, Aberdeen
Joined Sep 2000
12,588 Posts
Matt

Drop me a PM with your snail mail address and I'll stick a couple of 7 cell 250mah NiCds in the post for you if you like. I'm not using them any more and so you're welcome to them. They will fly a GWS Pico Stick for about 7 minutes or so and a 5oz model should be no problem. At the very least you'd get two more flights per session

If you want really long flights in that sort of model then LiPo is the way to go, the old Perkins-distributed 700mah Lions were about the first readily available cheap upgrade over here but there are better alternatives now. Even the old Lion packs would give 45 minute flights with a 10oz IPS-powered model. The JP LiPo charger sells at 16 and is good for up to 3 cells.

Leccy
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Old Jul 06, 2005, 08:46 AM
United Kingdom, Leighton Buzzard
Joined Sep 2004
548 Posts
will they be ok

hi

the model with bateries weighs 5oz so will those batteries still be ok?

Thanks MAtt
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Old Jul 06, 2005, 08:58 AM
HELL no you cant fly it!
lift off's Avatar
Joined May 2004
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If you are going to run an IPS motor on three cell you DANG well better have it in a
"C" gear ratio. Otherwise the motor will last 1/2 a flight.
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Old Jul 07, 2005, 07:37 AM
Random Flier
Oxford (UK) and Mtn View CA (USA)
Joined Nov 2002
1,404 Posts
Bah! When I was young... (etc etc)

Quote:
Originally Posted by lift off
If you are going to run an IPS motor on three cell you DANG well better have it in a
"C" gear ratio. Otherwise the motor will last 1/2 a flight.
Errr... doesn't that rather depend on the prop? I think your statement would better read "...you DANG well better know the relationship between volts in, prop, and gearing".

Quote:
vintage1 im 15 where the heck am I gunna get 19quid and then i need to get an expensive charger!
Well, you could always build the charger yourself. And you could always try your local electronics store for discarded batteries: for example, ex-cell phone batteries. Also ex-cell phone Li-Ion chargers. Or a used laptop battery pack. etc etc.

Reminds me of a good idea: a "Cheap" forum for doing R/C on a budget!
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Old Jul 07, 2005, 08:07 AM
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Allan Wright's Avatar
Lee, NH, USA
Joined Jun 2001
5,185 Posts
Find someone who bought these a while back and has upgraded to lipos, you can most likely pick up their charger and several packs (perfect for IPS planes) for a few pounds plus shipping.

http://www.rcgroups.com/links/index.php?id=3929
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Old Jul 07, 2005, 10:26 AM
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Newton, NJ
Joined May 2003
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Not to be the voice of dissent here, but I just wanted to offer an anecdote related to the original question. Up until this year, my father was flying a GWS Tiger Moth on the stock IPS motor/GB with an 8 cell 720maH AAA nimh pack. Believe it or not, it flew stronger(better climb) and for longer(20 minutes!) on that heavy brick of a battery than it did on the stock 6 cell 1/3AA nicad pack. That said, I do believe that 7 or 8 cell nimh packs in either 1/3AA (300maH) or 2/3AAA (400maH) are the best CHEAP solution to flying an IPS. The 6 volt pack you mention is not enough, as the others said, but it you had a few more cells, you could probably make something work. If you've any chance to save up a few more pounds, lithium polymer is definitely the choice to make.
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