HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Oct 18, 2011, 09:43 AM
Registered User
United States, WV, Calhoun
Joined Nov 2004
506 Posts
Discussion
Bird of Time ARF conv to Electric -How Hard

Tower sells a Bird of Time ARF.

How hard is it to convert this sailplane to electric?

I am thinking of using an inrunner? Maybe even a geared inrunner.

Any one done this conversion? And if so what power system did you use?

Thank you in advance for your replies.

Todd
skyhawk1 is offline Find More Posts by skyhawk1
Reply With Quote
Sign up now
to remove ads between posts
Old Oct 18, 2011, 10:11 AM
Thermal Junkie
Leadchucker's Avatar
Joined Sep 2008
3,213 Posts
It's an easy conversion and has been done many times.
Don't need an inrunner or a geared setup unless you want one. I used a 35-48-1300kv Rimfire outrunner motor with a 11 x 7 prop and it was gobs of power.

One thread here on BOT ARF conversion with more info:
http://www.rcgroups.com/forums/showt...ight=bird+time
Leadchucker is offline Find More Posts by Leadchucker
RCG Plus Member
Latest blog entry: Mini update on Kennedy Longhorn
Reply With Quote
Old Oct 18, 2011, 10:15 AM
Registered User
United States, WV, Calhoun
Joined Nov 2004
506 Posts
Thank you for the reply. I did a search but did not turn up the referenced thread. Now I'll do the research.

Thank you again. Todd
skyhawk1 is offline Find More Posts by skyhawk1
Reply With Quote
Old Oct 18, 2011, 10:19 AM
Thermal Junkie
Leadchucker's Avatar
Joined Sep 2008
3,213 Posts
My pleasure. If you have any questions just give a shout once.
Leadchucker is offline Find More Posts by Leadchucker
RCG Plus Member
Latest blog entry: Mini update on Kennedy Longhorn
Reply With Quote
Old Oct 18, 2011, 12:19 PM
Registered User
United States, NC, Lawndale
Joined Mar 2008
179 Posts
I just finished converting one. I used the Turnigy G10 motor from hobbyking with a 12X6 prop. 2200mah 3 cell lipo and still had to add some weight in the nose to balance. I also added spoilers. I added to much 5 bay per side. 3 would be enough.

When cutting the nose I cut at the point where the fuse diameter gave enough clearance for the motor. On the next one I will cut off the very tip on the nose where it is hollow and work my way back to the weight that is glued in, chip out the weight and then make final cut.

Good Sailplane, Tower increased price by $20 buck just after I ordered mine. Sill a good deal.
Tabasco is offline Find More Posts by Tabasco
Reply With Quote
Old Oct 19, 2011, 12:29 AM
the anthropocebo effect
kcaldwel's Avatar
Joined Jan 2007
3,463 Posts
I was just considering doing an e-conversion as well. Good info here:

http://www.wattflyer.com/forums/showthread.php?t=46714

Kevin
kcaldwel is offline Find More Posts by kcaldwel
Reply With Quote
Old Oct 19, 2011, 12:50 PM
Registered User
USA, FL, Hudson
Joined Dec 2009
193 Posts
I have just finished doing one also. I found it hard to figure out the degrees down and to the right so I made a panel and cut an ovel to match the front of the nose about where a 40mm spinner would match then built a small frame work and glued it in to make the angles. Then I just slid the nose in place, marked it with a sharpie and cut it with a dremel and thin cut off wheel. Spinner ended up matching almost perfectly.

I haven't had the maiden flight yet or built the spoilers. I am curious if Espirits new Albatros wing with aile. and flaps would just bolt into place. Hopefully it will and they make the wing assembly available seperately.

http://www.espritmodel.com/albatros-...-3s-e-arf.aspx
Troy S is offline Find More Posts by Troy S
Reply With Quote
Old Oct 20, 2011, 07:04 AM
FPV Desert Beta Test Center
Mesa, Arizona
Joined Nov 2006
2,303 Posts
Question for E-BOT pilots.
How much elevator deflection have you found necessary to maintain level flight at WOT? I realize it is going to be differant depending on motor, prop, etc but am looking for a starting point so not to loop it first time out.
Gary Evans is offline Find More Posts by Gary Evans
Reply With Quote
Old Oct 20, 2011, 09:48 AM
Thermal Junkie
Leadchucker's Avatar
Joined Sep 2008
3,213 Posts
Quote:
Originally Posted by Gary Evans View Post
.....How much elevator deflection have you found necessary to maintain level flight at WOT?......
I am assuming you mean climb out not level flight. Mine would climb out at about a 60* angle making aproximately 1200 FPM. It took about half down stick with thumb to keep her on this track. I don't know what this correlates to in actual degree or mm of flying stabilizer movement deflection. The manual says 15 mm maximum deflection up and down which is where I set mine, so I would imagine 7 mm.
Leadchucker is offline Find More Posts by Leadchucker
RCG Plus Member
Latest blog entry: Mini update on Kennedy Longhorn
Reply With Quote
Old Oct 20, 2011, 10:37 AM
Registered User
United States, NC, Lawndale
Joined Mar 2008
179 Posts
Quote:
Originally Posted by Gary Evans View Post
Question for E-BOT pilots.
How much elevator deflection have you found necessary to maintain level flight at WOT? I realize it is going to be differant depending on motor, prop, etc but am looking for a starting point so not to loop it first time out.
I was not able to get the recommended throw amount with the servo mounted in stab. The control arm on the servo had to be cut to short to fit. This did not make any difference. It does not have an elevator per say as the whole stab moves and thus very small throws make a large pitch change.
Tabasco is offline Find More Posts by Tabasco
Reply With Quote
Old Oct 20, 2011, 11:48 AM
Registered Rebuilder
United States, MD, Potomac
Joined Feb 2004
108 Posts
Quote:
Originally Posted by Gary Evans View Post
Question for E-BOT pilots.
How much elevator deflection have you found necessary to maintain level flight at WOT? I realize it is going to be differant depending on motor, prop, etc but am looking for a starting point so not to loop it first time out.
I did the conversion this spring and just about looped it on the maiden. As Tabasco says, with the servo in the tail you don't get much servo arm so not much movement. I traded off getting almost no up elevator at all so I could apply more power during the initial climb
jduvall is offline Find More Posts by jduvall
Reply With Quote
Old Oct 20, 2011, 12:55 PM
Gravity-Compliant User
Zaurak3's Avatar
Nebraska USA
Joined Mar 2008
1,450 Posts
I have one coming from Tower now, it should arrive tomorrow. With the Tower $20-off discount and their free shipping promotion, it was too hard to resist. I also already have a motor system that will work well in the conversion.

It's a beautiful model, I've always liked the appearance of this design, as a kid, I bought the Jetco kit for the Thermic 72 - a distant relative to the BoT. Am looking forward to some pleasant soaring with the big Bird!
Zaurak3 is offline Find More Posts by Zaurak3
Reply With Quote
Old Oct 20, 2011, 01:22 PM
the anthropocebo effect
kcaldwel's Avatar
Joined Jan 2007
3,463 Posts
Quote:
Originally Posted by jduvall View Post
I did the conversion this spring and just about looped it on the maiden. As Tabasco says, with the servo in the tail you don't get much servo arm so not much movement. I traded off getting almost no up elevator at all so I could apply more power during the initial climb

Moving the CG aft would reduce the pitch up at the faster-than-trim speed under power. The elevator will also get more sensitive as the CG is moved aft, so the throw on the stab would have to be reduced.

Of course, approach moving the CG aft carefully since too far back will result in a pitch unstable airplane. I suspect there is quite a way to go back from the recommended position though.

Kevin
kcaldwel is offline Find More Posts by kcaldwel
Reply With Quote
Old Oct 20, 2011, 03:47 PM
Thermal Junkie
Leadchucker's Avatar
Joined Sep 2008
3,213 Posts
On the spoilers, they are easy as heck to cobble up then cut in. I made mine from 1" trailing edge stock and cut them 9" long to cover the little 3/4 inboard bay then the next three bays from the centre sheeting out. Full 90 degree deployment will drop her out of the sky like a box of hammers, lesser degrees of use can be varied with throttle stick* or other slider switch to achieve glide scope desired.

On the servo in the tail bit. After some reading on other conversions, I opted to put mine next to the rudder servo under the wing and use a pushrod and bell crank setup for the flying stab. It takes a little thinking a bit of re-engineering to do it, but it's not really a big deal. I know it's two more connections and more places for slop to occur however mine came out just fine.


* All my sailplanes are off or on with motor control on a gear switch then the throttle stick gets used for flaps or spoilers. I wasn't sure about making this step at first but now will have it no other way. I'd rather have the more complete range of control over the flight surfaces (flaps/spoilers) and use the motor to get to altitude so I can soar.
Leadchucker is offline Find More Posts by Leadchucker
RCG Plus Member
Latest blog entry: Mini update on Kennedy Longhorn
Reply With Quote
Old Oct 20, 2011, 03:52 PM
Registered User
United States, NC, Lawndale
Joined Mar 2008
179 Posts
I do not have to add much down on climb with engine. I mounted the engine with some down and right thrust. I do not remember the degrees of down. It was in another post here or on the watt flyer forum, I will try to find it and post here. I think it was 6 degrees down????? and a couple degrees right. At any rate at just under full throttle it climbs without adding down elevator.
Tabasco is offline Find More Posts by Tabasco
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Bird of Time ARF: aftmost CG point Jerry In Maine Sailplane Talk 6 Dec 20, 2011 10:21 AM
Sold Bird of time arf - assembled never flown Bud Morrison Aircraft - Sailplanes (FS/W) 2 Apr 02, 2011 01:58 PM
Sold Bird of Time ARF. New in box. $120!! CT local or Cumberland Aerotow pick-up SPasierb Aircraft - Sailplanes (FS/W) 1 Mar 06, 2011 08:23 AM
WTB: Built Bird of Time or Bird of Time ARF Superman Aircraft - Sailplanes (FS/W) 1 Jul 14, 2003 04:06 PM