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Jul 08, 2014, 10:47 PM
RCRoger2001
Thread OP
Discussion

Spoilers needed for my B.O.T


Hello,

I'm going to Elec pwr my Bird of Time Glider and from all reports I'll need Wing mounted spoilers to help landing the Bird.

Are there any Glider Mfgs that offer different sizes and shapes of spoilers ???

Please let me know.

Thanks, rcroger
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Jul 08, 2014, 11:07 PM
AMA 7224
Leadchucker's Avatar
A couple pieces of 1" trailing edge stock about 9 or 10 inches long, an X-acto knife, a piece of 1/4 x 1/8 balsa to make a box and a couple servos is all you need. She'll drop like a brick.
Latest blog entry: Hangar 9 Fokker D VII
Jul 17, 2014, 05:39 PM
Proud member of LISF and ESL
Personally I would do the standard barn door type spoilers. As suggested, trailing edge material works great. See photo of my Spirit below or what is shown in the video of the Goldberg Electra.


Goldberg Electra Spoiler 3 (0 min 36 sec)



But if you want to buy something premade, here are some options.

I think these would technically be called airbrakes but they serve the same purpose. They include the servo so you just mount and connect them.

https://www.hobbyking.com/hobbyking/s...arehouse_.html

video
Glider Spoiler Servoless Left and Right Pair. (5 min 23 sec)


Review - Not entirely positive.
http://www.rcsoaring.com/rcsd/RCSD-2013-05.pdf



Alternate from Esprit Models - Much higher priced. Hopefully better quality too.
http://www.espritmodel.com/airplanes...-spoilers.aspx

e-flite electric spoilers
http://www.horizonhobby.com/products...ght--EFL491009


I-care airbrake
http://www.icare-rc.com/airbrake.htm
Last edited by aeajr; Jul 17, 2014 at 06:14 PM.
Jul 17, 2014, 08:14 PM
Registered User
I'm not sure you NEED spoilers if you're an experienced pilot and have a good sized place to land with not too many wandering obstacles like dogs and pedestrians. I wouldn't hesitate to fly one without spoilers under those conditions. On a smaller electric model, I found that running the motor at a very low speed allowed the prop to act as an air brake. That's no good for landing, but handy for getting down out of a thermal without going too fast. But spoilers do make things easier, especially for spot landings.

If you're going to fly in RES contests, be sure the spoiler blades are at least two inches forward of the trailing edge. I've heard that as you move them back, you get less of a negative pitch response but they will need to be a bit larger. Makes sense to me. If you're going to fly in Nostalgia, those spoilers need to be near the high point. Probably, for the BOT, with the leading edge of the spoiler at the trailing edge of the d-tube sheeting. There are some other requirements in the AMA nostalgia rules.

If you're not going to compete, you may find that it's easier to put in split flaps, which are kind of like the pivoting type of spoilers but on the bottom. More vulnerable to damage but, at least on a flat bottom wing, I'm sure they're easier to install.

I've only used the pivoting type (also called "barn door", at least in aeajr's post.

I think homemade "barn door" spoilers would be more in character for your BOT than the other types. If you do go this way, be sure to make the spoiler blades twist and warp resistant, don't wrap around them with Monokote, and make sure everything fits well. Otherwise, they'll make you come down a lot faster when open and a little faster when closed. There are a bunch of threads about spoilers on RC Groups, including some by me, some with pictures. You can probably find those as well as I can, because at the moment, I don't know where they are. Recommend looking in Sailplane Talk and Thermal forums.
Jul 17, 2014, 10:20 PM
Proud member of LISF and ESL
I would put spoilers in any R/E glider I was building from a kit. They are not necessary but are very useful.
Jul 17, 2014, 10:48 PM
RCRoger2001
Thread OP
Thank you for the very informative reply. NO I don't plan on any contest Flying. And YES I am an experienced Builder/Pilot both Glow/Gas Powered and Slope gliders etc.

After all these years, I'm tired of chasing all over the skies with a Glow/Gas powered Plane only to re-fuel it and do it all over again 11

A 2.5 to 3 meter "Floater" type Glider is much to my liking. i.e. Bird of Time and others like it

The only difference is now I would like the plane to be Elec Powered (Outrunner Motor & Li-po Batteries etc

(someone said it's better to use an In-runner Mtr because of fuselage space and Prop size ?????)

Thanks to all the dedicated RC Grps subscribers for ALL the info on this project. I really don't know how to pay them back !!!

MANY THANKS TO ALL rcroger
Jul 17, 2014, 11:48 PM
Proud member of LISF and ESL
Post lots of pictures during the conversion and don't forget the flight reports.

Note there are several threads here done by people who took the BOT electric.
Jul 18, 2014, 12:35 AM
Registered User
Are you going for the ARF, the kit, or a scratch build? I hear the ARF is considerably heavier, though that might have changed. I hear that the ARF is tail heavy, so maybe you could go low budget with an old geared Cobalt 05 if it's tail heavy enough. Lipos would still be good, though.

You may find that the BoT floats more when you try to land than your slope gliders unless they have comparable aspect ratios. However, I'm sure it's capable of more speed, when you want, than some of the other floaters like the Paragon or Aquila. Handy in a breeze.

I have a Mega inrunner motor that is rated for a huge number of amps and a fairly large prop but isn't all that wide. Something like that might work. But probably a smaller one as this one would be overkill. I'm thinking of using it in a Kaos 40 or a 3 meter sailplane for ALES. I think it might be too noisy in the first case and too powerful in the second!
Jul 18, 2014, 02:33 AM
Registered User
Quote:
Originally Posted by RCRoger2001
...
(someone said it's better to use an In-runner Mtr because of fuselage space and Prop size ?????)

Thanks to all the dedicated RC Grps subscribers for ALL the info on this project. I really don't know how to pay them back !!!

MANY THANKS TO ALL rcroger
Nn need for an inrunner, fuselage space is enormous for a 35 class motor.
Big prop size means inrunner PLUS gearbox, not inrunner alone !
You can have both using a gliderdrive outrunner-in-a-can type motor, 3858 840kv on mine, spinning a 14x7 from 3s, unlimited 45 degrees climb.

+1 for heavy fuselage of ARF. Check my recent posts about placing BoT wing on another fuselage.
Jul 18, 2014, 06:15 AM
Registered User
Brynmr's Avatar
Quote:
Originally Posted by lincoln
Are you going for the ARF, the kit, or a scratch build? I hear the ARF is considerably heavier, though that might have changed.
True but a side note, it's considerably lighter than the Mystique RES.
Jul 18, 2014, 06:26 AM
Fly to live- Live to fly
ultimatetwo's Avatar
Hope this vid help a little..., not neccesary at all 90 degrees opened, a good and mild response over 45-50 degrees with some 10-15 percent mix elevator up...
My opinion is that even with the dinamical brake efect of a big spinning at low rpm. folding prop, spoilers are a very good option to the BOT, cause in some situations, well adjusted and with the " ground efect " want to glide forever and doesn´t stop...
Regards.
Manolo.

(1 min 13 sec)
Jul 18, 2014, 08:18 AM
RCRoger2001
Thread OP
WOW !!!

Thanks for the info on the Elec Mtr/ Prop etc

I know the misc sizes of Gas & Glow Motors BUT Not Outrunner/inrunner Elec Mtrs

i.e. Size/Power/Prop/ESC etc I Know...I've been building/flying for a long time and have avoided the change over to 2.4 Radios,any and all Elec/Foam Stuff Me Bad !!!

What started all this was me buying a used R-2 Fox Elec Glider (minus the Rcvr and Battery) and buying a 2.4 Radio & Rcvr from R-2. I didn't get ALL the stuff needed to get it working once I had it in the Glider.......Programing the Radio ???? Binding the Radio & Rcvr ???

The Inst manual they kept sending was for the Wrong Radio so I think this was a Big waste of Money!!!

I used the folks at Cermark to help me get started with Elec etc,but they have closed shop and I'm many miles away from any Hobby Store so I'm relying on you folks for help

I've read the articles about the Elec/BOT and I decided to go that way. Easy Floater !!!

Modifications etc for the change over are no major problem once I get started with the Right Mtr, ESC, Battery,Prop etc .

THANKS Again for all the Help you folks sent. It's comforting to know there are Many "Decent, Down to Earth" folks that share the same Hobby and interests.
Thanks! rcroger 2001
Jul 18, 2014, 04:25 PM
RCRoger2001
Thread OP

BOT ARF vs Kit Built


Quote:
Originally Posted by lincoln
Are you going for the ARF, the kit, or a scratch build? I hear the ARF is considerably heavier, though that might have changed. I hear that the ARF is tail heavy, so maybe you could go low budget with an old geared Cobalt 05 if it's tail heavy enough. Lipos would still be good, though.

You may find that the BoT floats more when you try to land than your slope gliders unless they have comparable aspect ratios. However, I'm sure it's capable of more speed, when you want, than some of the other floaters like the Paragon or Aquila. Handy in a breeze.

I have a Mega inrunner motor that is rated for a huge number of amps and a fairly large prop but isn't all that wide. Something like that might work. But probably a smaller one as this one would be overkill. I'm thinking of using it in a Kaos 40 or a 3 meter sailplane for ALES. I think it might be too noisy in the first case and too powerful in the second!

I've heard the ARF is a bit heavier than the Kit Built version BUT....Is it really going to make that much difference????.

I'm just flying it in a Wide open area here "in the Sticks"

How much heavier is the ARF 5, 10. 20. 30 ,40. 50 . 60 oz more than the Kit ???

I'm a very experienced Builder/ Flyer ( No not the Olympics ) so I don't think a small amount of "Over Weight" will affect my Gliding.

However, That said, I really appreciate ALL The Helpful Info from everyone who answered my call for Help\..

You guys are GRRRRRRREAT !!!!

Thanks rcroger
Jul 18, 2014, 04:27 PM
Registered User
craigrrr's Avatar
Quote:
Originally Posted by aeajr
I would put spoilers in any R/E glider I was building from a kit. They are not necessary but are very useful.
I believe spoilers on a good RE thermaler ARE necessary.

I think any RE plane that thermals well should have spoilers, and the main reason is to get your plane extracted from boomers and back in one piece. Without spoilers on a big floating RE, you will have to, at times, flat spin the plane. And at times it will take something steeper than a "flat" spin. This could result in excess airspeed/wing flutter/destruction.

Spoilers on a RE such as the BOT are a necessity if you plan on doing serious thermaling. They add very little weight and complexity and do a lot to keep from losing your plane.

I rarely fly my favorite 3 meter electric RES without some deployment of spoilers at altitude.

Craig
Jul 18, 2014, 04:34 PM
Proud member of LISF and ESL
Quote:
Originally Posted by RCRoger2001
I've heard the ARF is a bit heavier than the Kit Built version BUT....Is it really going to make that much difference????.

I'm just flying it in a Wide open area here "in the Sticks"

How much heavier is the ARF 5, 10. 20. 30 ,40. 50 . 60 oz more than the Kit ???

I'm a very experienced Builder/ Flyer ( No not the Olympics ) so I don't think a small amount of "Over Weight" will affect my Gliding.

However, That said, I really appreciate ALL The Helpful Info from everyone who answered my call for Help\..

You guys are GRRRRRRREAT !!!!

Thanks rcroger
about 7 to 10 ounces heavier depending on how good a builder you are and the quality of the wood in the kit.

Go for the ARF, put in the motor, put in the spoilers, go fly.


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