New Products Flash Sale
Thread Tools
Old Dec 11, 2010, 05:57 PM
ratlm is offline
Find More Posts by ratlm
Registered User
United States, WY, Gillette
Joined Oct 2008
171 Posts
Discussion
greatplanes bird of time 118"

hi.living in gillette wy.farly new to gliders and i have a quetion.so here gos. will the great planes bird of time penetrate . i have to deal with a lot of wind. average about 8mph year around. i need to knowif ill have to ballast beyond anything reasonable in 15 to20mph wind.would the rizer 100 work better??and id like to expand the wing of the sig riser to110 or better will that kill the plane?im to new just a few 2meter and ahandlanch or 2.y guys got to forgive my typing and spelling.id just like to see the plane when i get more than 200ft. up.http://static.rcgroups.com/forums/im...es/smile.gifid apreciate as much solid info as i can get. realise there are a lot of gliders out there but this is what i can afford.(fixed income) thnks guys. bob minor ratlm2540@msn.com ps posted on sailplane talk and was advised to go here
ratlm is offline Find More Posts by ratlm
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 12, 2010, 05:25 PM
Miami Mike is offline
Find More Posts by Miami Mike
Pompano Hill Flyers
Miami Mike's Avatar
Miami Lakes, Florida, USA
Joined Mar 2003
8,494 Posts
If you mean the Dynaflight Bird of Time, it's a slow floater and doesn't really penetrate very well.
Miami Mike is offline Find More Posts by Miami Mike
Reply With Quote
Old Dec 12, 2010, 05:55 PM
lincoln is offline
Find More Posts by lincoln
Registered User
United States, MA, Waltham
Joined Dec 2001
7,229 Posts
That's a relative thing. I bet it penetrates better than a GL, especially with ballast. If you have glider clubs near you, you might be able to pick up a faster glider for less money than you'd pay for the kit and materials. But these days, it might have ailerons. Not necessarily advisable, depending on your skills. And ailerons on a long skinny wing are not the same as on a stubbier wing on a powered aircraft.

I don't know what airfoil the Bird of Time uses, but it may go faster if you make your own ribs so you can borrow some airfoils from something like a Bubble Dancer. If the wing is thinner you might add some carbon fiber strips to make up for it. (They're cheap.) Or, if you have a good table saw and some nice sugar maple, that will be somewhat stronger than the spars that come with the kit. I've used maple rc engine bearers for spars, but I don't know if that comes in the right size.

15 or 20 mph is a lot of wind unless you are on the slope.

I suppose your budget may not extend to these, but I've heard of an RES version of the Smooth Genie Pro. There's a wood kit for $200. Or perhaps you can scratch build it. Same comments re the Scooter 3M at Skybench.
http://www.vintagesailplaner.com/SmoothGeniePro.html

A cheaper, though somewhat smaller, alternative might be the Mountain Models Scepter. I don't know how it compares with the two gliders you've mentioned, but I flew one and it didn't strike me as especially slow. And you could also make your own ribs for it. Since the wing has a lower aspect ratio (I think), a thin airfoil might be less of a problem.

If you're using an RES glider on a windy day, do yourself a favor and tie it down! Putting a big rubber band over the fuselage at the l.e. and attaching to a stake in the ground works well.
lincoln is offline Find More Posts by lincoln
Reply With Quote
Old Dec 13, 2010, 09:22 AM
Lacquerhead is offline
Find More Posts by Lacquerhead
Wood Chucker
Lacquerhead's Avatar
USA, TX, Allen
Joined Nov 2009
1,514 Posts
I also have to add in the DJ Aerotech Chrysalis. I recently finished building one and it flies considerably faster than the Sophisticated Lady I have been flying. Here in north Texas we're also pretty used to having winds in the 8-20mph range. 30mph is pretty common any time a front moves through. In general I wouldn't fly the SL in winds over 10mph unless I intended to fly backwards as winds aloft are always higher than surface winds. In it's electric sailplane guise the Chrysalis tips the scales at 2lbs. 9oz. and at that weight I was pretty darn surprised how fast and how flat it glides. I have the sailplane fuse on the board right now and it should be a good 8-10 oz lighter even if I have to use the same amount of nose weight. I didn't cut lightening holes in the tail feathers the electric fuse but I will on the sailplane fuse for sure.

If you're willing to look at a 2M plane, take a look at the Chrysalis as well.
Lacquerhead is offline Find More Posts by Lacquerhead
Reply With Quote
Old Dec 22, 2010, 09:57 PM
aeajr is offline
Find More Posts by aeajr
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
25,329 Posts
8 mph is not a lot of wind. 15 to 20 is a lot of wind. Most of our glider club will go home in 15 mph even if they are flying high end molded ships. They just don't want to deal with it.

Typically, unless I am in a contest I don't head to the field with that level of wind either. But if it picks up while I am there, I just drop in some lead and launch.
aeajr is offline Find More Posts by aeajr
Reply With Quote
Old Dec 27, 2010, 11:09 PM
LWeller is offline
Find More Posts by LWeller
Registered User
Holland, Michigan
Joined Dec 2006
461 Posts
Ratlm,

If in fact the Bird of Time you ask about is the one from Dynaflite I have some experience with this glider. I own two. Both have been motorized because our field does not lend itself well to winch or bungee unless the wind is out of the east or west. I have converted 7 of these gliders to electric. However, they fly very much as they would as a winch launch glider. In fact one of them use to be winch launched.

They are really nice flying gliders. There is seldom a day I go out that I can't catch lift with this plane. I have caught lift trying to land on several occasions and rode it back up to speck height. It is so gentle to fly that I often sit in a chair and take my hand off the stick for minutes at a time. I also have a sig Riser 100". It's a nice plane and easy to fly but more of a floater than the BOT. In my opinion the BOT will penetrate better. I enjoy flying the BOT more.

Having said that, When the wind gets up to around 12mph. the fun begins to go out of flying to the extent that I have to work harder to fly the plane. It will handle that wind ok but when I find lift it can get a little violent at the edge and sometimes kick the plane back out of it. So you have to work a little harder flying the plane. This is pretty much true of everything I thermal fly. When flying slope gliders I like the wind between 15-30 mph. I agree with ajear, if I know the winds will be high I work on my planes at home but if I'm flying and the wind picks up I'll stick it out at the field until it gets uncomfortable or it drops back down.

Some of my favorite flying is done in summer evenings when the air is stable to the point the glider doesn't really go up in lift but at the same time it doesn't sink much either and you will just glide around in what seems forever at a nice altitude. My point is that the winds often taper off in the late day and you can still get in some good flying.

I attached some photos of my two BOTS. I put flaps in the bottom of the center section of the wing to slow it for landings. These flaps are like speed brakes that are built into the wing and are not part of the trailing edge.

It makes me excited to look at these pictures this time of year. The shortest day of the year is behind us and I have gliders I can't wait to fly. I hope this helps. I suspect you will have a good time with what ever choice you make.

Larry
LWeller is offline Find More Posts by LWeller
Reply With Quote
Old Dec 28, 2010, 01:27 AM
Miami Mike is offline
Find More Posts by Miami Mike
Pompano Hill Flyers
Miami Mike's Avatar
Miami Lakes, Florida, USA
Joined Mar 2003
8,494 Posts
Quote:
Originally Posted by LWeller View Post
I put flaps in the bottom of the center section of the wing to slow it for landings. These flaps are like speed brakes that are built into the wing and are not part of the trailing edge.
I've never seen a set-up like that before. I'm not even sure they qualify as "flaps" if they're not part of the trailing edge. I don't know what you'd call them.







Miami Mike is offline Find More Posts by Miami Mike
Last edited by Miami Mike; Dec 28, 2010 at 01:37 AM.
Reply With Quote
Old Dec 28, 2010, 06:52 AM
Wazmo is online now
Find More Posts by Wazmo
Duane
Wazmo's Avatar
No. VA
Joined Nov 2004
1,635 Posts
Quote:
Originally Posted by Miami Mike View Post
I've never seen a set-up like that before. I'm not even sure they qualify as "flaps" if they're not part of the trailing edge. I don't know what you'd call them.
Can't tell for sure from the photos, but they look like split flaps.
Wazmo is online now Find More Posts by Wazmo
Reply With Quote
Old Dec 28, 2010, 08:02 AM
aeajr is offline
Find More Posts by aeajr
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
25,329 Posts
Quote:
Originally Posted by LWeller View Post
Ratlm,

snip...

I attached some photos of my two BOTS. I put flaps in the bottom of the center section of the wing to slow it for landings. These flaps are like speed brakes that are built into the wing and are not part of the trailing edge.

It makes me excited to look at these pictures this time of year. The shortest day of the year is behind us and I have gliders I can't wait to fly. I hope this helps. I suspect you will have a good time with what ever choice you make.

Larry
I am preparing to build a Dynaflite BOT right now. Clearing off the work bench and finishing up some repairs first.

My colors are the same as yours with white on the top, black on the bottom and transparent red on the open bays. Looks great on yours.

I like the embedded speed brake/flap. Clever implementation.

I will be putting spoilers on mine. I will fly it in club RES competitions. But for our BOT we are going to have a one design contest. Since the original BOT did not have spoilers I will tape them shut for that contest.

My first two gliders, a Spirit and a Sagitta 600 were both RES so I have always liked RES gliders. I also have an AVA.

Mine will be for winch and hi-start. I will be carbon capping the spars and am considering changing the wing joiner to make the wing more suitable for winch launching. That 1/4" steel rod does not seem like it could take much of a winch launch.

Mine will be for winch and hi-start. However I am considering putting in a motor too. I would mount the motor in such a way that I could remove the prop and cover it with a solid nose block when winching. Remove the nose block, mount the prop and spinner and I can electric launch.


Quote:
Originally Posted by ratlm View Post
im to new just a few 2meter and ahandlanch or 2.y guys got to forgive my typing and spelling.id just like to see the plane when i get more than 200ft. up.[url]
Like to see it when you get it more then 200 feet up? I expect to fly mine to 2000 feet or more, like my other gliders.
aeajr is offline Find More Posts by aeajr
Reply With Quote
Old Dec 28, 2010, 08:34 PM
LWeller is offline
Find More Posts by LWeller
Registered User
Holland, Michigan
Joined Dec 2006
461 Posts
Split flaps they are. About 1 1/2 years ago I was preparing to publish a BOT electric conversion for 'RC Soaring Digest'. I had taken pictures from several of my conversions and wrote a rough draft of the article. My wife and I had just put the house up for sale to test the waters. The yard, largely perennials, took a lot of our free time and as much as we loved the place we had other things to do with our free time. You can imagine what I wanted to do with my share! The house sold and we had to scurry to find a new place. Medusa Motors went out of business. When I was ready to pick the task back up it seemed a bit out of date. If I were doing it now I would probably choose one of Steve Nue's motors.

I am attaching a few teaser photos and if there is interest I will post my conversion for the BOT winch to electric. You an see from the pics that I barely cut the tip off the nose for the motor mount. Many of the conversions I've seen have cut way back on the nose. My goal was to keep the lines as close to stock as possible given the face lift required. I found a 36mm Graupner spinner a perfect fit.

Six of the seven built with split flaps were all converted by just removing the bottom covering of the wing from the open rib section behind the leading edge to spar sheeting. Three of the BOT flaps I made by laminating two sides of a 1/16 balsa sheet with .007 carbon fiber material. The other 4 were made from 1/16 carbon fiber sandwich material by Dragon Plate. Because they are so thin they must be very stiff. They are extremely effective slowing down the glider. The only wing I completely removed covering to work on was the one pictured above and only because I wanted to change the look. Installing the split flaps added a side benefit of strengthening the center section due to the spruce spar I added for the flap hinge. I can add details if there is interest. There are many more photos that depict the process.

I don't mean to side track the original question. The BOT is a great glider - powered or not.

Larry
LWeller is offline Find More Posts by LWeller
Reply With Quote
Old Dec 28, 2010, 08:55 PM
LWeller is offline
Find More Posts by LWeller
Registered User
Holland, Michigan
Joined Dec 2006
461 Posts
Aeajr, I have been following some of your posts and threads and think its great your club is doing the one design thing. Especially with the BOT. I think you must be building the kit model with the wood fuselage. The ARFs have no center wing joiner. The tip joiners are wood and aluminum sandwiched together for a very stiff spar.

There was a lot of hype and angst several years back about the wing on the ARFs being poorly designed, weak and easily broken on launch. This has been corrected. None of the ones I built in the past three years have had the old style wing. Still if you have the covering off for flaps or spoilers it is the time to investigate the construction. One of ours was very light with glue on the spar and had to be opened up and better glued. Not a problem since your scratch building.

My first BOTs were set up for a 3200 mAh lipo. Subsequent builds I made provisions for a 2200 lipo and a 5 cell NiMH receiver pack. I can still get 5-6 climbs but stay up for the better part of the day (in theory) on the receiver power.

You have some nice airplanes in your quiver. I will be very interested to learn what you and your members think of the BOT.

Larry
LWeller is offline Find More Posts by LWeller
Reply With Quote
Old Dec 28, 2010, 08:56 PM
aeajr is offline
Find More Posts by aeajr
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
25,329 Posts
Thanks for the info and the photos. Much appreciated. Yes it is our club doing the one design.

I am going to build the plane from the kit. I received the kit for Christmas. Have spent some time cleaning up my shop so I have room to build. I have two sets of repairs to do first. My Supra has a flap servo issue. No biggie!

My AVA has a broken wing tip that I tore off on an over agressive launch during an Eastern Soaring League contest. Once I have those fixed, then the BOT gets started.
aeajr is offline Find More Posts by aeajr
Last edited by aeajr; Dec 28, 2010 at 09:08 PM.
Reply With Quote
Old Jan 08, 2011, 07:45 PM
ratlm is offline
Find More Posts by ratlm
Registered User
United States, WY, Gillette
Joined Oct 2008
171 Posts
hey guys i started this thread and got busy here i didnt see any results or rplys for a while and left it for a while.larry you have really sparked my intrest anew and settled me on tne bot.i apretiate everones input. will keep reading whatever is posted.we are moving in the next month-monthandahalf(when they close)will start my build then.i wil use your flaps larry but will try a diffrent motor setup(fixed income)will also build from the kit not arf.i like to build.thnks all for input.please dont stop.i glean from it all thnks bob rtlm
ratlm is offline Find More Posts by ratlm
Reply With Quote
Old Jan 08, 2011, 08:38 PM
northwest is offline
Find More Posts by northwest
Registered User
Joined Jun 2005
103 Posts
I ordered the BOT ARF version mainly out of curiosity due to the size and very clean wing-tips at such a low price.
Overall it was a big waste of money for me.
Well, the model was extremely effective at finding lift and climbing out to a speck...it was really floaty and reluctant to come down. Infact getting back down was a real big problem. The wings would flex and flop a whole lot and I was always concerned on the launch (large size hi-start) and when trying to maneuver out of strong lift. There is no spoiler or flap so there was always a danger of breaking the wing.

The problem was that it handled so poorly compared to other gliders. It is very short-coupled for that long wingspan, and the dihedral is a bit flat. This causes unacceptable swinging and oscillating unless locked into a constant circle.

Now the rigging of the flying stab is a whole other story. The max travel you can get is totally inadequate. On release from the hook, full fwd or back stick was not uncommon to prevent a stall or stop a dive (incase you didn't allow a passive fly-off). There wasn't enough elevator to do a spin either. So when you get cought in the big stuff you really had to work to bring it back safely, with the wing flexing so much.

The BOT wouldnt penetrate worth a fart beyond 15kts but by then you would be fighting to control the plane with its limited maneuverability.

I would recommend an OLLY 2 or a RISER 100 instead. I use industrial strength velcro from home depot to stick in up to 4oz of lead in my AVA when it gets windy. You could try that.
I would recommend an OLLY 2 or a riser 100 instead.
northwest is offline Find More Posts by northwest
Reply With Quote
Old Jan 08, 2011, 10:43 PM
aeajr is offline
Find More Posts by aeajr
Proud member of LISF and ESL
LI, New York, USA
Joined Mar 2003
25,329 Posts
Thanks for the assessment of the ARF.

I will be building mine from a kit, carbon capped spar and adding spoilers for winch launching.
aeajr is offline Find More Posts by aeajr
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Build Log LISF Bird of Time One Design Build Thread Powerbud Sailplane Talk 1024 Jun 10, 2015 06:59 AM
For Sale Bird of Time kit (Dynaflite) mwhitman Aircraft - Sailplanes (FS/W) 3 Nov 12, 2010 06:25 PM
Sold Mark's Models Bird of Time (Damaged, free) quartercase Aircraft - Sailplanes (FS/W) 3 Nov 07, 2010 10:26 PM
Sold 118" Bird of Time Sailplane ARF (NIB) Richard_Allen Aircraft - Sailplanes (FS/W) 4 Apr 16, 2008 10:39 PM