[NSRCA-dist8] Contest Practice, Boise, ID

Mon Apr 19 09:28:09 AKDT 2010

Wow, talk about opening a can of worms, John!  lol     There's a lot of choice out there as far as 
motor/controller combinations.  First things first.... Most of the F3A motors swing a big prop, 20-21".
You need to know if you are going to have enough ground clearance for the prop, or if you will be able
to use landing gear tall enough to get the clearance.  The other route would be to use a motor that has
a higher KV and use a smaller diameter prop at a higher rpm.  Once you figure out which direction you need to
go, you can choose from a wide range of motors, then pick a controller that will handle the amps the motor is 
capable of drawing!  One thing that is somewhat puzzling is that controllers usually handle more amps than what it
listed by the model name....probably has something to do with the 'safe work load' rating the company decided to 
use.  There is no industry standard as far as any of this goes.  Sort of like glow plugs!  There has been a lot
of activity in the past year with new motors coming out.  With the fast pace of technology, it's hard to keep us
with what's available.  I can give you a range of motors and controllers that will give you some idea of what to 
look for.  As an example, with an AXI motor you have a choice of the 5330/F3A for swinging the big 21" prop, or 
the 5330/18 motor with a 19" prop.  Flying with the smaller prop at a higher rpm is more like flying glow in the respect
of flight speed.  The F3A type motor is more geared to slower flight.  AXI also has a new motor out listed as
5325/24... it's smaller and lighter, but I haven't heard enough about it yet to make any kind of decision. Also,

you have to be concerned with weight.  If your plane is light, say 1 1/2 pounds under the limit, obviously you could

use a a little smaller combination than a plane at the weight limit.  

As far as speed controllers, you can't go wrong with the Jeti 77 Advance Opto... it's a good controller that has been

used a lot over the last four years in pattern.  One concern is the heat sink which is pretty small, but that is solved by adding another heat sink to it...pretty simple!  One thing you will find is that there is a big difference in weight in

controllers.  You can get 3 ounce differences pretty quickly.  The other thing is the weight of wires.  You'd be amazed

at how many ounces you can save in being able to trim out a bunch of the controller/battery wire. 

As far as batteries goes, you will need to  pick something in the neighborhood of 5000 mAh for flying Masters. Flying in the wind can get you into the range of around 3500 mAh in a flight.  The other consideration is the C rating.  If you have a high amp motor, you might want to consider a battery in the 20C rating or a little higher.  Batteries have no industry standard either, and you will find that one company's 15C rating may be as good as another's 20C rating battery.  There has a been a push to go to a wattage rating for batteries to try to get everything on a more even playing field.

One thing about electric is that it's like everything else... You get what you pay for.  That's not to say that you can't get a good working combination at a reasonable price.  It's just that if you don't 'overbuild' with more than what you need, you have to be more on top of the situation as far as requirements to keep everything happy!  There's nothing worse than getting all this stuff, then finding out that you should have chosen something else.

The combination of motor/controller that I listed above is just an example.  It really depends on what you have as far as weight to start with.  If you want, you can tell me what you are starting out with as far as weight, and prop clearance, make a decision on the route you want to go, and I can give you a multitude of choices.  The sky being the limit!  Good luck!

Rex

> From: justjohnf at w-link.net
> To: nsrca-dist8 at lists.nsrca.org
> Date: Mon, 19 Apr 2010 08:39:34 -0700
> Subject: Re: [NSRCA-dist8] Contest Practice, Boise, ID
> 
> Hey Guys... What is the preferred combination of motor / speed control / 
> batteries for Pattern planes??.. I am putting a P&L Flash Dance together and 
> want to give the OS 140's a rest..??? Anybody have items for sale???
> John F
> ----- Original Message ----- 
> From: "Gordon Anderson" <gaa at owt.com>
> To: "AK, ID, MT, OR, WA, WY" <nsrca-dist8 at lists.nsrca.org>
> Sent: Sunday, April 18, 2010 8:43 PM
> Subject: Re: [NSRCA-dist8] Contest Practice, Boise, ID
> 
> 
> > Thanks! We hope to get there pretty early, we are going to hit the road 
> > Thursday night and get as far as we can so we can have lots of practice 
> > time. I will need it!
> > Thanks for the heads up on the road status, we made our reservations at 
> > the best western on airport way so we are all set, rates were pretty good.
> > Is there power at the field or should I bring my generator to charge my 
> > batteries?
> >
> > Looking forward to flying with you guys!
> >
> > --Gordon
> >
> > On Apr 18, 2010, at 8:35 PM, astropuppy wrote:
> >
> >> Yep Gordon,
> >> The field will be open all day Friday for practice. I will be leaving 
> >> work at noon to meet, greet and fly. If someone arrives earlier than noon 
> >> a quick call to my cell phone will get you the gate combo.
> >>
> >> As a warning, The freeway though Boise is a mess especially the area 
> >> around the airport. Specifically the Orchard and Vista interchanges are 
> >> being rebuilt. From I-84: Unless you are staying downtown or near the 
> >> mall; Do Not go to city center, follow signs to Mountain Home.
> >>
> >> Anybody camping at or going to the field will want to drive though Boise 
> >> eastbound on I84 and get off at the first exit past the rest area "Blacks 
> >> Creek". Turn right at the stop sign and meander though the desert until 
> >> you see a couple houses on the right. Turn left shortly after the blue 
> >> (highway) sign that say "BARKS" onto our dirt drive way. Ya'll be able to 
> >> see our sun shelter well before you turn.
> >> _______________________________________________
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> >> NSRCA-dist8 at lists.nsrca.org
> >> http://lists.nsrca.org/mailman/listinfo/nsrca-dist8
> >
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