+c0re-

I'm looking for a nice electric P-51 mustang, preferably ARTF, however
everything I've seen is either smaller than I'd like or a lot of the
original lines have been lost converting it to a model.

One option I'm trying to research is buying an IC plane, of which I've found
several I like. They all use around a .60 2 stroke IC engine, I'm wondering
if there is a straightforward way of comparing this to it's equivalent
electric power, or whether it's a lost cause.

I'm thinking that probably attempting to convert something that needs a .60
IC to electric is going to result in a ridiculously heavy model but perhaps
I'm wrong?

any advice or info would be much appreciated, thanks in advance

paul mcintosh

Ridiculously heavy, or EXPENSIVE. See if you can find an old Dynaflight kit
on Ebay. They were very light and fairly scale. A plain bearing .40 flew
mine just fine. With that you would be in a reasonable cost ball park.

--
Paul McIntosh
http://www.rc-bearings.com

chris

700 Watts is about a horse power. So If you know the bhp of your 60
you'll know how many watts to get ot of your propellor. then you work
out how to get say about 1000 watts into your prop and get your prop
working with the right thrust and airflow to fly the plane you want to.

At the moment nicds are about £20 for a 7.2 volt pack and can give 30 to
40 amps for a short while. So 10 cells gives 12 volts and 40amps X 12
volts gives about 500watts. So you need about 20 cells, a brushless
motor to handle that current and a big prop perhaps with a gearbox.

If the nicds are too heavy or you want more duration go for LiPolymer
which has a better energy density.
So if we say £60 for the batteries, £100 for the motor and another £100
for the speed controller and charger, you won't get much change out of £300.
If you're still serious get in touch with someone like puffin models
who'll sell you a working system.

Chris John

+c0re-

Thanks for the replies, I think this is probably a bit beyond me and sounds
like it'll be a bit of trial and error getting the right prop etc.

the natural philosopher

Not ridiculously heavy, but ridiculously expensive.

The cheapest way would be to use an Astro Conbalt 60 brushed motor and
as many cells as it needs. If the budget stretches to it use lithium
cells, but expect to spend almost $1000 on the power train.

If that doesn't frighten you off, have a look at http://www.astroflight.com,
and ask again on the ezone in the power forum for even more esoteric
options in the occult art of Big Electric Warbirds.

http://www.rcgroups.com/forums/forumdisplay.php?f=13

the natural philosopher

No, its not HARD to get that right. Its just that it takes a little
research, and a lot of cash.


Battery prices go up linearly with power. 0.60 power is twice as
expesnive as .30 power, which is twice as expensive as .15 power etc etc.

Whereas linear dimensions come down as the cube root of power. So a .15
sized model is half the size of a .60 sized model roughly.

Hvae a look at RBC kits (http://www.rbckits.com) and the UK dealer
http://www.puffinmodels.com - if you can bear to com down to that sort of size
and drop retracts etc, you can have a very exciting model for under 500 quid.

+c0re-

Thanks again for the info, I had no idea that the cost rose so sharply for
higher powered stuff, I don't think I want to spend a lot more on an
electric model than on a comparable IC one. I am pretty interested by that
RBC mustang though, I'll have to look into building one as opposed to
getting an ARTF one.

paul mcintosh

Ridiculously heavy, or EXPENSIVE. See if you can find an old Dynaflight kit
on Ebay. They were very light and fairly scale. A plain bearing .40 flew
mine just fine. With that you would be in a reasonable cost ball park.

--
Paul McIntosh
http://www.rc-bearings.com

chris

700 Watts is about a horse power. So If you know the bhp of your 60
you'll know how many watts to get ot of your propellor. then you work
out how to get say about 1000 watts into your prop and get your prop
working with the right thrust and airflow to fly the plane you want to.

At the moment nicds are about £20 for a 7.2 volt pack and can give 30 to
40 amps for a short while. So 10 cells gives 12 volts and 40amps X 12
volts gives about 500watts. So you need about 20 cells, a brushless
motor to handle that current and a big prop perhaps with a gearbox.

If the nicds are too heavy or you want more duration go for LiPolymer
which has a better energy density.
So if we say £60 for the batteries, £100 for the motor and another £100
for the speed controller and charger, you won't get much change out of £300.
If you're still serious get in touch with someone like puffin models
who'll sell you a working system.

Chris John

+c0re-

Thanks for the replies, I think this is probably a bit beyond me and sounds
like it'll be a bit of trial and error getting the right prop etc.