JOHN! JOHN! JOHN!  An electric Ringmaster? Oh the sacrilege!!!!!

John,
   If the Ringmaster is scratch built with electric in mind one of the power systems mentioned in this post should work great. http://stunthanger.com/smf/index.php?topic=3342.0 Both power systems have flown airplanes in the 28-34oz AUW range with very good results. I don't know what the upper limit is, but I would imagine 38oz would not be a problem.

   If it is a direct glow to electric conversion it may take a little more power to get the desired performance. I would guess it would come to more than 40oz if it was a kit built glow airframe. The AXI 2820/10 would be a better choice.

   The AXI 2814/12 weighs 3.75oz and the AXI 2820/10 weighs 5.25oz. A Thunder Power 3S 4000mah weighs 9.25oz and you can add 1.25oz for the ESC/timer. From these weights you can estimate you AUW and pick a motor. 

   Good luck........

   I would be careful trying to use the same power system on two different sized airplanes. It's a great money saving suggestion, but it might turn out you saved nothing in the end. Imagine trying to needle back (detune) your .46 on a ringmaster.

   If you want to run the AXI 2826/10 on a 3S battery you will have to turn a large diameter prop with very high pitch at a slow rpm. For a more successful setup what should be done is use a motor with less winds (higher Kv) like the 2826/08. Changing motors (winds) defeats the purpose and your back where you started. At that point you might as well go down a motor size or two and save money and weight. Trying to use the same motor on 3S and 4S batteries is a tough job (at least in C/L). 

   If you are going to build two airplanes using the same power system, (say a Ringmaster and P-40 for arguments sake) the only savings would be on the purchase of one motor ($81.50 for the 2814/12 and $85.60 for the 2820/10). I don't think the money saved is worth the risk of having a poorly flying Ringmaster and good flying P-40 or vise versa. Why not spend the extra $80 and have two well setup power systems. You already bought the 3S and 4S battery packs, ESC and timer.

   Of course if you plan on buying both power systems, or would like to experiment, try the larger motor on the Ringmaster with the smaller battery and let us know how it works. It may be an unusual setup, but it may work OK. 

   Rudy, are you are talking about Will Moore being the first to use the AXI 2826/10? I may be wrong (correct me if I am), but I believe Walt Brownell was the first to use it. He flew this setup at the 2005 NATS.

Again good luck and let us know what you decide on and how it works.

OK. Here are suggested combinations which I have gleaned from this and other forums and which reputedly will electrofly my Ringmasters:

AXI 2820/10 and 3S 4200, Phx 45 ESC and APCE 10X6 or 115.5 - the jmp timer

AXI 2820/10 on 3S with an 11X5.5 or 10X6 - the jmp timer

AXI 2820/10  on  Thunder Power 3S 4000mah - the jmp timer

AXI 2820/10 3S 4000mah - the jmp timer

AXI 2814/12  If the weight comes in at 38 oz or less- the jmp timer

AXI 2826/10 maybe with a TP3S2P 11.1V 3,800 or 4,000 mAh- the jmp timer

HXT 42-40 1050kv 35A Brushless Outrunner Motor, Hextronic 30 Amp esc and a 10x5.5 APC-E prop at 24 Amps, 264 Watts and 9420 rpm. (for a weight of  around 34-36 oz) - the jmp timer

Though not always mentioned a suitable ESC is assumed and a props from the 9 x 5 up to 11 x 5.5 have been mentioned several times.

My Ringmasters are both scratch built from old Sterling plans and no attempt to save weight was made since they were intended to be flown for sport and as trainers for my son (long since grown and out of the nest). They have been “re-kitted” several times (learning to fly inverted tends to cause that) so they may not be the lightest. Both have been monocoated and may carry some extra oil under the covering. Still balancing inverted on one wing tip and 1 lb postal scale under the other (weight box end) gives 15+ oz so I would guess that they are in the 32 to 38 oz range.

I have ordered a HXT 42-40 1050kv 35A (cheap) and intend to give it a try. I’ll post how it works out.

Meanwhile, I would STILL like to hear from anyone as to their actual successful setup in a Ringmaster or those other Sterling Ringmaster clones.

Thanks for the information so far and happy landings.

John