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OCB
03-26-2006, 04:26 PM
I just ordered the trainer from AK Models. The flying weight is 5 lbs. I would like to set this plane up with a brushess. Performance? Well, I'm not thinking of blistering speed but maybe some very light aerobatics. What do you folks think of the BP 3520-7 motor or is that too big? I want to go cheap on this one. Thanks Folks!

Twmaster
03-26-2006, 06:02 PM
With a plane that big there is no such thing as 'cheap' when it comes to brushless power. Not only will you need a motor but a suitably matched ESC. Then there is the question of feeding it. How many and how big of a Lipo pack will you need?

On 5 pounds to get any aerobatic performance you'll need between 85 and 100W per pound of the plane RTF.

Some of the AXi motors will do the job, E-Flite has some new 25 and 32 sized motors out that will do >500W.

Just some food for thought.

OCB
03-26-2006, 07:26 PM
Maybe I should have rephrased the setup diferently; I meant I want to save money by staying away from the expensive components; ie: Axi, Castle Creations, Thunder-Power, etc.

agshane
03-26-2006, 08:21 PM
OCB:
We are using the BP 2915 with the 40A ESC and 11.1 4000 mah lipo in a 72" Telemaster. The plane weighs in at 5.75lb and does great.
BP 2915-5 Outrunner Brushless Motor (http://www.balsapr.com/view.asp?id=V814870&pid=V284038) provides 400w which will put in the power range needed. The motor and ESC can be had for less than $100 including shipping.
Hope that helps.

OCB
03-26-2006, 09:34 PM
Thanks agshane, that is the kind of info I'm looking for! And I'll take more to get this bird up in the air.

OCB
03-30-2006, 12:17 AM
agshane,
What size prop and batteries are you using? How about flight time? Thanks a bunch!

agshane
03-30-2006, 12:39 AM
OCB:

Prop 12X6 Electric

11.1 4000mah 3 cell Lipo discharge rate 15 - 20C (poly-quest)

Flight Times generally between 24 and 30 minutes depending on speed
(You probably could get by with a 2500 for one flight of 15 minutes)

Have a separate receiver battery on board due to the number of servos.

OCB
04-01-2006, 07:24 PM
agshane,
Thanks again! I'm going with your setup. Just a few questions more. Will this setup allow me enough power to do a few light aerobatics (slow rolls, loops)? And the receiver battery; do I just get a receiver battery and plug it into an unused receiver "slot", no cutting wires or anything like that? I will only be using 3 servos. The way I understand this is: the receiver battery will power the servos and receiver. I'm I right on this? These big planes are a little different from my little park flyers. But with some help from you folks, I can do this.

agshane
04-01-2006, 07:41 PM
OCB

If you are only using three servos and your at 11.1 volts for power, then you shouldn't have to have a separate receiver battery.

If you do however use a separate battery, you will separate and cut the RED wire coming from your speed control and then the battery pack would plug into the socket marked "B".

By the way that speed control plugs into the #3 channel on the receiver (futaba).

The setup we have talked about should provide 400 Watts, as long as the plane weight is not more that 5lbs then REAL mild aerobatics should be a snap. (That's 80 watts per pound)

clenaghen
04-03-2006, 06:04 PM
[quote=agshane;57987]OCB

If you are only using three servos and your at 11.1 volts for power, then you shouldn't have to have a separate receiver battery.

If you do however use a separate battery, you will separate and cut the RED wire coming from your speed control and then the battery pack would plug into the socket marked "B".

By the way that speed control plugs into the #3 channel on the receiver (futaba).
quote]

agshane - I have been pondering the Telemaster Electro myself for awhile now, and being new to this hobby, am a bit confused as to the separate battery issue to power the servos. I think I understand what you are saying, but want to verify. On my receiver (Spektrum) I usually plug the ESC into the #3 channel, as you mention. In order to have enough battery on this plane to power the engine and 4 servos, I would need to cut the positive (red) lead from the esc to the receiver then have another battery connected directly to the receiver? So, I would have a battery connected directly to the esc and plugged into channel #3, like usual, and another battery connected directly to the receiver. My Spektrum receiver is labeled on channel #1 as Batt, so that must be what that channel is for (separate battery)?

Did I get this right?

agshane
04-03-2006, 06:45 PM
You got it right!

I would have a battery connected directly to the esc and plugged into channel #3 This battery powers your motor. The red, white and yellow wires from the esc go to the motor. The other end of the ESC have red and black wires. They go the motor battery.
There is what looks like a servo wire and plug that also is attached to the speed control and that's the red wire that you snip and plug into the throttle on the reciever. (Separate the 3 wires, cut the red wire and insulate the ESC end)

My Spektrum receiver is labeled on channel #1 as Batt, so that must be what that channel is for (separate battery)? Yes, the BATT is where the battery plug goes in this case.

But before you do all this, check your speed control specs and make sure that you can not run four servos!

We use the Telemaster's in the school because they fly slow, are easy to take off and, if trimed right, will virtually land itself. It is absolutely the best trainer available, gas or electric!!

clenaghen
04-03-2006, 07:48 PM
Cool! Thanks for the clarification! I have also been looking at the BP motor that you mentioned as well. They are currently out of the 60A speed controllers and wont have any in for a few weeks. I'll give the BP products a try, and in the mean time, get my Telemaster Electric on order and built. I am very interested in the wind handling of the Telemaster since all my current planes are foam and dont tend to handle moderate wind at all. This time of year the weather here is always windy.

Doc Pete
04-03-2006, 08:31 PM
. I am very interested in the wind handling of the Telemaster since all my current planes are foam and dont tend to handle moderate wind at all. This time of year the weather here is always windy.

What foamies do you have????

agshane
04-03-2006, 08:51 PM
Cool! Thanks for the clarification! I have also been looking at the BP motor that you mentioned as well. They are currently out of the 60A speed controllers and wont have any in for a few weeks. I'll give the BP products a try, and in the mean time, get my Telemaster Electric on order and built. I am very interested in the wind handling of the Telemaster since all my current planes are foam and dont tend to handle moderate wind at all. This time of year the weather here is always windy.

You only need a 40A speed control for the BP2915-5. Here's a link for these motors and speed controls http://www.xushobby.com/servlet/Detail?no=108 (http://www.xushobby.com/servlet/Detail?no=108). I think he has stock on everything.
Flew this morning, the winds in Little Rock were at 15 mph. The Telemaster did fine after I put in two clicks of down trim for landing. Flew for about a total of 15 minutes and still had over 1/2 charge left.
The last flight was tough, with winds gusting to 23mph. Was lucky, found a real soft patch of ground outside the runway and got it down. :D

In 10 - 12 mph wind the Telemaster does just fine. :)

clenaghen
04-03-2006, 08:57 PM
(Hmmmm duplicate post... thought it didnt post)

Anyways, I have a foamie STC I built and the Parkflyers Cessna 182. Also have a Tigermoth 400 thats pretty much done, just waiting for electronics

Oh, and have a Cox micro warbird F4U and a Parkzone P-51 that I wont fly until my flying skills get better. Oh, and of course the Slo-V.

darkside212
04-04-2006, 02:16 AM
Hey Agshane,
what kind of amps are you pulling with that motor/prop?

agshane
04-04-2006, 02:20 AM
Full throttle = 33 amps
1/4 throttle = 5 - 8 amps

Flies mostly at 1/4 throttle, unless its windy :eek:

darkside212
04-04-2006, 02:26 AM
Great I have a superstar 40 I'd like to convert to e power

darkside212
04-04-2006, 02:27 AM
do you think a 10*6 or 11*7 would suffice?

agshane
04-04-2006, 03:27 AM
Darkside:

Your Super Sport 40 weighs in at 5.5lbs which means to be aerobatic your are going need a power setup that provides 450-500 watts.
Here's a link that will allow to make some choices. I think you should step up your motor and go to a 4 cell lipo and choose a prop off this table.
http://www.balsapr.com/view.asp?id=V814870&pid=V736362
You can fly that Super Sport 40 with our Telemaster setup, but you would probably be very disappointed.

clenaghen
04-05-2006, 06:44 PM
OCB:

Prop 12X6 Electric

11.1 4000mah 3 cell Lipo discharge rate 15 - 20C (poly-quest)

Flight Times generally between 24 and 30 minutes depending on speed
(You probably could get by with a 2500 for one flight of 15 minutes)

Have a separate receiver battery on board due to the number of servos.

What kind of battery you using for the servos? I assume you dont need much?

agshane
04-05-2006, 09:16 PM
A normal reciever pak, 4.8 and 650 mah or above.

OCB
04-28-2006, 12:29 AM
Where can I get a motor mount for the 2915-5 motor?
Thanks!

agshane
04-28-2006, 02:13 AM
OCB:

The motor mount should be included with the motor. See the following link: http://www.eflightstuff.com/motorstop3.htm.

If you already have the motor, take some heavy paper and mark the mounting holes. Then overlay on a piece of 3/16" of aluminum and drill the mount holes. Then match that to your firewall, and secure.

clenaghen
04-28-2006, 04:28 PM
Just to give an update here....

My Telemaster has been finished. On recommendation, I purchased the 2915-5 motor, a 11v 3850mah LiPo and things work great! I have been pretty conservative with my flying (only 2 flights with this combo.. dont want to get to crazy after putting $400 into this thing). I ended up with a APC 12x6 slo flyer prop because the APC 12x6E thin electric I had was causing quite a bit of vibration throughout the plane (unbalanced I assume). So, with the Slo Flyer prop I was only pulling 25 amps at full throttle. I picked up another APC 12x6E and will try it again. I assume I will pull a few more amps with that prop than the Slo Flyer prop. Both flights I have flown in about 10mph winds, and I ended up flying around at about 2/3 throttle.

2nd flight I was short on time and didnt have a chance to fully charge my battery. Battey was at about 4v per cell and I flew for about 10-15 minutes and still didnt drain the battery (meter showed 3.7v per cell).

I didnt install flaps on this and not sure they are needed. This thing still floats to the ground. In fact, I have overshot my landings both times. Once you drop the plane down then flare out to land, the thing just keeps floating. You need to make sure you have plenty of space to land the first few times you try to land. Of course, most of the problem is my inexperience.....

Flying a plane this big as a newbie is pretty deceiving. It flys faster than it seems. I am used to smaller planes that once they get out there a ways they are hard to see. This plane is big enough that you can fly it out quite a ways without losing plane orientation.

Agshane - how is the acrobatics with this setup? I know this plane wont do much regardless, but as far as loops, rolls, etc, how does it handle with this motor setup?

redgiki
04-29-2006, 03:54 PM
I ended up with a APC 12x6 slo flyer prop because the APC 12x6E thin electric I had was causing quite a bit of vibration throughout the plane (unbalanced I assume). So, with the Slo Flyer prop I was only pulling 25 amps at full throttle. I picked up another APC 12x6E and will try it again.

Don't just buy new props in hopes they'll be balanced. Purchase a balancer, or make one up yourself using a long needle and a hunk of balsa, and shave or sand the heavy side. The difference in noise and power between an unbalanced vs. a balance prop is substantial, and I have NEVER purchased a prop which was perfectly balanced at the time of purchase.

Doc Pete
04-29-2006, 06:27 PM
. The difference power between an unbalanced vs. a balance prop is substantial,.

Yup, something that is a freebie, besides the reduced airframe vibration.......Good thought.......