What is the proper size engine for my electric glider?

[hiTmanhiT]

Hello!
I just got a old glider from a guy cleaning up his garage.
I have no idea what brand it is.
It is probably somewhat old.

It used to have a old brushed motor in it, but I threw it out, and now want to get a brushless system in it instead.
I am all new to gliders, so I have no idea what kind of engine is required for these.

It's a fiber-glass fuselage and a balsa wing.
The wing span is at about 2.7 meters (106 inches)
And the whole thing with servos weighs about 1250 grams(44oz)

Would you need some pictures to maybe?

I would like to order a engine from [link=http://hobbycity.com/]Hobbycity[/link]

So if you got a suggestion or question, come with'em!

Thank you very much! [:D]

Here is a pic, dont know if this will help you.
As you can see it needs some work. Crack in the fuselage, no rudder or vertical stabilzer etc etc. But a nice little project eyh?
Maybe you can see what plane this is as well? I have no idea.

glider1.jpg (148.06 KiB) Viewed 35257 times

[crampy]

Nice looking glider. I too am looking to see what size motor to put in my Spectra I've bought back to life just recently. Old power system was a monster of a brushed motor, with an equally big NiCad battery pack and a 8x4 prop.

I'm keen to see what people think for yours or my glider.

[RobC]

I've experience of two similar size gliders, a 100" Flair Sunrise lightweight floater, and a 103" MPX Cularis which is about 60 oz rtf. I've flown both of these on a 2815 920kv 400W outrunner with a 3s 2250mAhr LiPo and a 60A esc. I think you should be looking for less than 1000Kv motors capable of handling 40A+ for a 3s cell, running somewhere between 11*4 up to 12*6 folding props. This means you won't be running the motor or esc right on the limit. My setup takes about 39A on a full battery, probably 35A or less in the air.
The Sunrise was on the edge at these levels, full throttle on less than max climb would cause the wings to flutter but it was a real old school floater with an undercambered wing. The Cularis will climb out to a spec in the sky half a dozen times on one charge using an 11*6 prop. It's also fully aerobatic on this power!
Yours looks somewhere between these extremes, so if you aim for about 300W+ you should do ok.

[Mr Ed]

Nice looking glider. I too am looking to see what size motor to put in my Spectra I've bought back to life just recently. Old power system was a monster of a brushed motor, with an equally big NiCad battery pack and a 8x4 prop.

I'm keen to see what people think for yours or my glider.

This is a nice little 2M glider and it had a speed 600 boat anchor in it along with those led NiCads. A great motor for that is from Hobby King and is the KD A20-22L on a 10X6 folding prop and you can get a good folding spinner from Hobby King but don't buy their props. I buy my props from Esprit models and use Groupner or aeronaut props. That's a good 200 watt motor and I run a 30 amp ESC with it, but it only pulls 20 amps. It will be more then enough power to fly that Spectra and then some. I use that motor in all my 2M gliders. I also use a 2200MAh 3S battery, but that is more for the CG then anything else. You will need to put everything as far forward as you can to get the CG to come out right. That boat anchor was heavy. I get a good 6 climbs out of that battery and still have plenty left after and it will fly much better too with most of that weight out.

Ed

[crampy]

Nice looking glider. I too am looking to see what size motor to put in my Spectra I've bought back to life just recently. Old power system was a monster of a brushed motor, with an equally big NiCad battery pack and a 8x4 prop.

I'm keen to see what people think for yours or my glider.

This is a nice little 2M glider and it had a speed 600 boat anchor in it along with those led NiCads. A great motor for that is from Hobby King and is the KD A20-22L on a 10X6 folding prop and you can get a good folding spinner from Hobby King but don't buy their props. I buy my props from Esprit models and use Groupner or aeronaut props. That's a good 200 watt motor and I run a 30 amp ESC with it, but it only pulls 20 amps. It will be more then enough power to fly that Spectra and then some. I use that motor in all my 2M gliders. I also use a 2200MAh 3S battery, but that is more for the CG then anything else. You will need to put everything as far forward as you can to get the CG to come out right. That boat anchor was heavy. I get a good 6 climbs out of that battery and still have plenty left after and it will fly much better too with most of that weight out.

Ed

Awesome cheers Mr Ed.

I'll definietly look into that. Yeah the stock motor certainly was a bit of an anchor, not to mention the battery pack.
I've got a handful of 2200mah 3S LiPos and a Mystery 30amp ESC sitting around doing nothing, so might have found a home for them.

Cheers again, now got to go and get her in the air.

[hiTmanhiT]

I bought a Turnigy 35-42 1000kv with a 40amp ESC.
Had the maiden yesterday. Flies like a beauty! Thermal soaring sure is a lot of fun! I will definetley buy more gliders.
Got a Dynaflite Talon full build kit, for hang-flying, looking forward to complete it.

Here is my Multiplex Alpha 27, with the new motor and a Graupner 12x6 folding prop.
http://www.mortenbilet.net/bilder/multi ... ha27/7.JPG

[Roger]

I installed a towerpro 2409 18 (1000kv, 20amps max) in my old hand launch "chucko" glider - wow, what a difference. I'm still having trouble with getting the prop to fold after turning of the motor though, even with the brake active... Good set up, runs with a 3s, 20C 1600Mah Lipo and a 25amp towerpro speed controller.
With a 9x5 Folder installed it draws 13 amps, and therefore 156 watts or so... Pulls my little glider almost vertically, heaps easier that biffing it and hoping to catch a thermal!!!

[Roger]

Think I might have solved the prop folding, thought I had the brake on, but I reset the speed controller last night and the motor is now "braking" when I release the throttle the motor quickly comes to a stop.