Size of Motor for a Gillows Balsa model
 

I recently bought the giant scale Gillows Dauntlass model built by a guy who really knew what he was doing. The model is set up for 4 channel, it has all servos in ect, but it does not have the motor or speed controller.

What would you recommend as a motor / speed controller for this type of little plane? It is built very well and is very light. Not much power would be needed I would think.

I have no idea on smaller electrics, so what set up should I use, what kind of battery ect, all would be helpful.

Please put it on a scale and let us know EXACTLY how much it does weigh. There are useful rules of thumb to estimate power requirements based on AUW... we can work out something for you.

http://www.hobbyking.com/hobbyking/s...er_1700kv.html
Around this size of motor works great in balsa tissue models. I like the rule of thumb of a 100 watts per lb. An average out runner can consume about 3 watts input power per gram of motor weight. A 10g motor is good for about 30watts, a 40g motor would be good for 120W in (constant not burst). Just good rules of thumb, your results may vary. So a 16g motor providing 48 Watts input power in a 1/2 pound (8oz) model works out well. Get the weight of the model and do the simple math to chose the right weight motor. Than you'll have to figure on a Kv. With this type of airplane I tend to go with the lower Kv motor so to be able to swing a larger diameter, lower pitch prop. Hope this helps

[QUOTE=zeroback;11739979]http://www.hobbyking.com/hobbyking/s...er_1700kv.html
Around this size of motor works great in balsa tissue models. I like the rule of thumb of a 100 watts per lb. An average out runner can consume about 3 watts input power per gram of motor weight. A 10g motor is good for about 30watts, a 40g motor would be good for 120W in (constant not burst). Just good rules of thumb, your results may vary. So a 16g motor providing 48 Watts input power in a 1/2 pound (8oz) model works out well. Get the weight of the model and do the simple math to chose the right weight motor. Than you'll have to figure on a Kv. With this type of airplane I tend to go with the lower Kv motor so to be able to swing a larger diameter, lower pitch prop. Hope this helps[/QUOTE

Do I consider the total weight of the plane including Battery and motor? I don't think it will even be a pound, very light plane. The guy who built it really knew what he was doing.

http://www.rcuniverse.com/forum/atta...mentid=1969875

I use the all up weight. In general the electric power system ( servos, pushrods, control horns, hardware. Motor and mount ESC, connectors and battery pack ) will weigh about what the empty airframe does (+/- 10%). These are ball park rules of thumb I have found to work well for pure bread electric airframes not conversions or one size fits none type of planes (but still good guidelines) So If your empty frame weighs 6oz plan on choosing gear that weighs a total of around 6oz. Note most good gear will have the weight listed in the add. Choosing a lighter weight higher cost ESC so to carry a bigger battery is an example of trade offs. Contrary to popular belief I use an ESC that is rated as close to the max amps the rig will pull. Modern ESC's do fine running at max current all day, just stay within spec. Most now have overload protection so a quick prop strike or even a locked shaft results in the ESC shutting down. So if I have an estimated AUW of 12oz I would be looking for roughly a 25 to 35 g out runner motor. Also note that how an OEM's spec their gear can vary quite a bit between manufactures. Great thing about this level of the hobby most parts are relatively low cost.
By the way that is a great looking plane.

That scale design has relatively small wing area compared with most parkflyers so be aware that it will have relatively high wing loading (probably at least 12oz-16oz/sq.ft). It may prove to be tricky to fly and may need to be flown fairly fast to keep it aloft. I hope this is not your first RC plane... if you don't have a lot of stick time I'd suggest learning to fly with a floaty type trainer (5oz/sq.ft) before risking such a beautiful model.

http://www.flybrushless.com/
I almost forgot.. here is a good site for motor info

Thanks for the tips, this would be the 9th plane I would have in the air: (2 Trainers, SIG 4* 60, GP Coursair 40, Parkzone F4F, Flyzone Beaver, Twinstar 40). I will be a bit nervous with wind because it is so light and such a great little model, but beyond that, I should be OK with the speed and wing loads....That said, I really do appreciate the help.

You are way ahead of me in flying experience! You'll be fine.