Building a BOT

[onewingwilli]

Help! I'm kit building the Dynaflight Bird of Time and need to know how you go about making the outer wing leading edges. The instructions say that they need to taper to the end of the wing. Do you taper first then round the leading edge? Or round the leading edge then taper from the back of the leading edge balsa?
Should I use a plane or just sand and sand and sand to get the taper? This looks very hard to do, get a rounded front edge and a taper that are equal on both wings. If this makes any sence to anyone I'd appreciate your help. onewingwilli :confused:

[Ollie]

First of all, you should sort the four sticks for the leading edges of the four panels by weight. Use the two lightest pieces for the tip panels. Spray a flat surface lightly with 3M75 repositionable contact adhesive to hold the sticks in place while you work. When the spray has dried, lay the leading edge pieces to be tapered side by side on the contact adhesive with the sides to be tapered uppermost. Use a very sharp, low angle block plane or a razor plane to taper the sticks. Check frequently during cutting with a straight edge to show where material needs removal. Measure the height of both sides at several stations along the length to make sure the plane isn't cutting too much on one side. If the plane isn't cutting smoothly, skew the blade to the direction of cut to lower the cutting angle. The softer the material the lower the cutting angle should be for a smooth cut. The cutting edge needs to be sharp enough to shave hairs. With the proper tool and technique the job takes less time than it does to write about it.

You could also do the job with long, straight sanding blocks of a variety of grits but it would take longer and you would have less control. Ideally the sanding blocks should be longer than the sticks you sand. You could put plywood stop blocks at each end of the the sticks. If the height of the plywood stop blocks are made the height of the finished sticks, you can sand the sticks down to the blocks and stop sanding when the sand paper touches the blocks. Again, it is necessary to check frequently with a straight edge during the sanding process to insure the taper is straight and measure the sides to insure they are even. Start with coarse grit and proceed to finer grit as the taper approaches final shape.

If you take too much material away, it's not the end of the world. Just replace the sticks and don't make the same mistake twice.

It just seems hard to do because you haven't done it before. You can develop a love of craftsmanship by practising it patiently. Good results are their own reward.

[onewingwilli]

Got it!! I was having trouble seeing how to get the two wing sections to match up but planning them together and final fine sanding makes sence.
I think I'll round the leading edge first so I can see how much material to remove in the taper process.

I'm hoping to keep this thread open for future questions. Keep checking back, this looks like it's going to be a long intresting road.

[Ollie]

Don't round the leading edge untill it is glued onto the wing panel. Then use an airfoil template to guide you in contouring the leading edge. How accurately the leading edge of the airfoil is contoured and faired into the rest of the wing has an important effect on the plane's performance and handling. The effort to do it right is a one time investment that pays dividends every time you fly.

Try to put behind you the idea of doing it easily at the expense of accuracy. Once you get past the learning curve of a new skill it will be easier. The investment in learning a skill will last you a lifetime. An expert is a person who has made every mistake in the book. A smart person is someone who doesn't make the same mistake twice. A genius is someone who does it right the first time.

BTW, a solvent called GooGone will remove the 3M75 residue from the smooth flat work surface when you are finished. Also, you could use double stick tape between the bottoms of the sticks and work surface instead of 3M75 to hold the sticks still while you taper them. Iv you use tape, be careful not to break the sticks when prying them off after tapering.

[onewingwilli]

I'll taper first, then glue the square but tapered leading edges to the ribs, then round the leading edge using my template.
Thank, that seems to sense.

Been sanding and weighing ribs today. Looks good with all the ribs in place. Still haven't glued any yet. Looks like I'll need to make slightly oval holes in the AA ribs for the joiner tubes since I may need a little wiggle room when I joint the two wing halves together. Who wrote the instructions for this thing. Have thay caught him yet:rolleyes:

Hope to have some pictures one of these says

Thanks again Ollie. I'll keep ya informed of my progress such as it is.

[BMatthews]

A couple of more ideas for you to consider....

With the tapered but square leading edges in place do the shaping in stages.[list=1]
Draw up a very large enlargement of the first 1 inch of the wing section and add in the leading edge location.
Add tangental lines from the sheeting to leading edge intersection and one more intermediate steeper tangent line to show the roughing out cuts to define the leading edge shape.
Start with planing a single angle into the leading edges. Work them down so this first angle is tangental to the upper sheeting. A piece of masing tape on the sheeting next to the leading edge will help prevent any damage that you didn't want. Remove the tape at the end and do the last bit of sanding to blend out the tape thickness in the leading edge.
Add in the second bevel angle. An angle wedge from scrap wood can help you judge holding the plane or sanding block to the correct angle.
Add the tangental bevel to the lower surface as per above.
With these 3 bevels (two upper and one lower) defining the basic shape of the leading edge you should be able to lightly blend it all to a smooth curve. Use the accurate leading edge templates to help with this.
Remeber that it's easier to remove than to add at this point. Go easy with the sanding and check the shape often. But don't be afraid to take more off until you're sure that it's perfect.
Use finer paper when you're close to the final shape to control how much wood comes off. Folding it into a three or 4 layer pack will add some stiffness to the paper for control.
[/list=1]

I did a write up about the wing joiner for another post one time. I'll see if I can dig up a link a bit later for ya. It basically lets you build the whole center in one piece and then cut through the tubing sleeves after for a perfect alignment.

[BMatthews]

Here's that bit from the other post about a foolproof way to install the joiner rod sleeve........

First off you're going to need a piece of K&S alluminium tubing that's a nice but not loose slip fit over your joiner rod.

I like to build up the center section with the wings on two building boards proped up at the correct dihedral angle. While I'm at it I keep a 1/32 to 1/8 gap between the two root ribs. Build up the whole center area with the tubing in one piece at this point running through the center and glued in well to the spars. Preferably it fits between the spars but if you can't do this keep it as close as possible. If it's between the spars I mix up some epoxy and balsa dust or other light filler to a nice putty and cram that in around the tubing to fill the whole gap between the spars. This locks the spars to the joiner tube. Thanks to the epoxy putty webbing on these bays is optional. If the tubing doesn't fit between you'll want to glue the tubing to the spars with the same putty used to fill all the gaps and then wrap the whole mess with kevlar thread or tow fibers from some unwoven kevlar cloth. CA well to lock the whole thing together. And add your rear alignment pin while it's all on the board. Cut the ribs down as required to fit around all this mess. Add the sheeting last so you've got access to wrap the thread around the spars.

Now use a razor saw to cut through the aluinium tubing in the gap. Add 1/32 full section root ribs to prevent hanger rash and file the ends of the tubing stubs down flush. Done, and guaranteed alignment.

This was for a smaller electric model. For the BoT I'd add 1/32 ply webs just after jamming the epoxy putty into place to box the spars more firmly. Also your spars are in line fore and aft and are wider so your joiner tube will fit totally within the spar gap. Use some balsa scraps to line it up as best you can before the epoxy putty without being too crazy and your alignment will be fine.

[onewingwilli]

here's a pictureC:\My Documents\My Pictures\webpic259.jpg

[onewingwilli]

Ok, guys here's not a picture. How do I get a picture into my post?
I've clicked on IMG in the Vb code and it ask for some http stuff???? I'm trying to put in some pictures from my files, I've tried attach file ...no good. I already reduce the picture size to less than 10Kb
now I have to get the picture from my files to the post?????
Help.

[rrowley]

I think you just use the attach button and not the img button.

[onewingwilli]

Do you mean the attach file? I've tried. I don't think it worked but here's another try.

[onewingwilli]

Nope nothing. Rrowley, your picture came through just fine. That thing must be bigger that 102Kb though. I thought that was the max size of the fill you could send. Are you talking about the attach file area at the lower left of the post reply page that has a "browse" botton to find your files. That's the one I'm using and nothing comes through when attach a file and post the message ? Any help?????

[rrowley]

Yes, down below the reply area. All I did was hit the browse button and select my picture, mine is a 98k jpg. press open on the dialog box and then submit reply. I don't get it. E-mail your pic to me and I will look at it and try to post it.

[onewingwilli]

Sorry about the delay my computer just died and I had to reboot. I'll give it a try, what is your email address/ I'm going to try and sena a picture with this also

[rrowley]

There you go, you got it. To email someone on the board you press the profile button on one of their posts and then press send email to xxxxx.

[onewingwilli]

Hey. It worked I'll now try and submit these pictures. Thanks anyway Rowley.

[onewingwilli]

Well, just called my internet provider and it wasn't my computer it was their server. All the buttoms to see profiles and such were not coming up on my computer screen. I think I was doing it right from the start but my IP server was not sending my pictures. Hopefully everything is corrected now.
So much for my computer problems, here are a few pictures of the building progress on my BOT. Many thanks to Ollie and BMathews and you too Rowley for your patients.
First layout of the inner wing panel

[onewingwilli]

Here's another of the entire wing. Nothing glued yet just test fitting.

[onewingwilli]

Here's one of the two center sections ready to have the wing rod glue-up. I'll then join the two sections together to make one center section and two outboard panels

[onewingwilli]

The final glueing of the center sections. Everthing fit just right and the dihedral was spot on. Sometims it's better to be lucky than good.:)

[onewingwilli]

Final one , me starting on the outer wing panels. More to follow.

[thepilotbruss]

I'm happy to see a thread detailing the construction of the BOT. Good Job and keep it coming.

[Steph280]

So how would you rate Dynaflite's BOT kit? Is it fairly easy to build?

I've been thinking about getting one for electric conversion.

Stephen

[Ollie]

If ease of construction is a high priority, the Skybench Aerotech Big Bird would be a much better choice. It has a similar appearance, 100 inch span, laser cut precision parts, better wood selection and it has been designed for easier assembly.

The Dynaflight BOT kit often has some poor quality wood that needs replacing, die crunched wing ribs and, a complex elevator drive mechanism. By poor quality wood, I mean wood that is warped, of uneven density and grain or, two hard and heavy for the application. On the plus side, it has larger size and excellent handling qualities when built with light balsa.

[onewingwilli]

Steph, I'm about 75% done with the wings so I can't comment on the body construction. Let me tell you what I've built so you can judge my building skills agains yours. I've built a Gentel lady, very easy but not the greatest quality die cutting, flies great, I've built a Skeeter, a litle too small and fiddly for me but not bad, flies not so great , has become a static model because of skitish flying habits, I've also built two foames, a Highlander and a Zagi, few building techniques apply to a built-up plane.
When you first open the box of the BOT you want to just close it up and send it back...all the lumber, is there a plane in there????
Once you start, however, it becomes a little less daunting. A word of advice, read the instructions, put them away and build the plane like you think it should be built. Not having many planes to compare it to, I can't comment on the wood, I guess it does seem a little uneven in quality and the die cutting especially of the wing tip ribs could be better, but nothing unmanageable. There is a lot of planning and sanding to do but read the advice of Ollie and Bmathews in this string for some great help.
All in all I'd give the construction part of the BOT a B- for ease of construction but it will always get an A+ for beauty. Should have a few more picture by tomorrow or Monday.
my advice so far ...go for it if you like construction just as much as flying. A very intresting project so far.

[loneflyer]

I know this a bit off topic but what are you using to protect your plans? Is there some thing better than the ol waxpaper i been using for yrs.?? Thin CA always seem to make it stick to the ribs !!! looks like you are using somthing different.

Thanks,
Larry

[MTT]

I have used this with good results : Plan Protector (http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LC4455&P=1)

Michael

[ken troxell]

steph 280...i converted a skybench big buird to electric and it is now my sailplane of choice! i am selling my silent dream 2.5 and fvk impulse 2. if you decide to go this route move the servos aft to the wing trailing edge. with a trinity geared car motor up front i still had to add 1oz of lead to the tail. runs on 7 cells. a 14x9.5 prop. that gives about a 60 degree climb angle....ken

[onewingwilli]

Steph, I use wax paper for most of the work I do and my plans are usually riddled with holes and a little glue at the end of the project. For some parts I do use two thick pieces of glass, read that very heavy, over the plans. I use the glass to hold two flat pieces of wood together while glueing, or cut pieces of wood right over the plans. The glass comes from two old end table tops and is about 1/2 inch thick. I sandwiched the three piece of wing-tip together and press them between the two pieces of glass with a few brickes on top. I've heard that some people get warping with alaphatic glue here but with this method , believe me there was no warpage.
I still get a little of that CA sticking to the wax paper you talked about when I don't use the glass, but if you peel the part away slowly and carefully there is no problem.

Here are some pictures of the outer wing panel being mated to the inner wing panels. As you may be able to see I use wax paper between the two panels to keep epoxy glue from sticking the two panels together perminately. Man does this site need spell check:D

[onewingwilli]

Here is the end result of the two wing panels being joined together with a carbon rod. I will then cut between the two panels with a razor saw and insert a thinner carbon rod into the two halves in each panel. Hard to visualize but I'll try and get a picture when I get to this part.

[onewingwilli]

Maybe I better explain more about that last picture. The hollow carbon rod is inside the joiner boxes, that other carbon rod you see is just a carbon rod I put into the inner panels to add stiffness. This is my own idea and is not called for in the plans. I'm just hopeing it adds some torsional rigidity, which I understand the wing needs.
Mayby this picture of the whole wing (with my big thumb in the upper left corner) will help to explain.

[onewingwilli]

Now for some technical questions for you guys. Why are these pictures showing up so HUGE!!!!! I thought I reduced them just like the last lot. Sorry for the size, I try to make them a bit smaller next time.

[onewingwilli]

Here are some photos of the nearly finished wing. Only the sheeting remains to be done but the shots of the wing tip joiners will make more sence without the sheeting. I know the joiner rods don't look parallel but it's because the two wing sections are lying flat insted of at the proper dihydrel angle.

[onewingwilli]

and another. The rods are different lengths to make thier insertion into the reciever rods easier.

[onewingwilli]

The joined wingtip. It's incredibly tight. Next I'll sheet the wings and do my priliminary sanding. More shots then

[onewingwilli]

last one all the parts

[KnotEye]

You left us hang'n! Is it flying? Did it turn out as well as you had hoped?
Post some picts!

I got into reading your project that it sparked me to order the original plans from RCM.
There was so much bad press about the qaulity of the wood and cutting in the kit , that it made me decided to build from ... SCRATCH.

I notice that you have gussets on the trailing edge of your ribs. Is that necessary?

What else could your recommend?

POST PICTS!

[onewingwilli]

Sorry I left you all hanging, illness in the family, she happened to be my photographer too.
I'm back now and I have completed the wing, covering and all, made the elevator and all the tail assembly, just finished the rough sanding of the body, boy a lot of balsa hit the floor. Since my photographer is out of commission for a while I'm going to give it a try...pray for me.
:confused:

[onewingwilli]

Nope Try this

[onewingwilli]

I think I've got it. Here's one

[onewingwilli]

Soon I'll be able to tell you what the picture is.. maybe even walk and chew gum at the same time...naaaaah:p
I think this is the nose . Just rough sanded so far but starting to take shape

[onewingwilli]

And last for the night

[onewingwilli]

Still a lot to do but it's getting there. Hopefully I'll be able to keep up with this project and keep you great people informed as to my progress. This is still the best forum I've ever been part of.
Signing off for the night

[KnotEye]

OneWingWilli,

Nice Picts - Thanks for sharing

Nice covering job. Looks smooth.

I'm think'n of doing the leading sheets in Copper Pearl Monokote and the rib and trailing using something like 'Aerospan', semi-translucent white.

I see that you went with the suggestion to keep the fuselage as narrow as possible. Did you layout your electronics yet to see how they fit?

Did you extend the fuselage to move the tail back? ... or is pretty much to plan?

The RCM plans have the wings attached by ye'ol' rubber bands. Not sure how Dynaflite has it designed... but I was think'n of 2 fwd pins / 2 aft nylon bolts.

I'm thinking of doing the BoT wing as a 3 piece. The trick will be to keep the ouboards LIGHT. You have given me some ideas by sharing your tip panel pin & tube solution.

Thanks for returning to your story.

[onewingwilli]

Cam123 here's a few thoughts;
1. Don't uses monocoat,,, gets brittle after 2-3 years
2. Don't use black anything looks soooo cool but shows ever singly flaw. My Cub Yellow ultracoat is fine, looks very smoth but everywhere I put black don't ask should have gone with plane yellow on the entire plane. Live and learn
3.Don't follow any of the above suggestions, It's your plane and should reflect your style. Copper pearl sounds great , going to have to go to the monocoat site to see what it looks like.
I did a lot of sanding on the body. Put 3/8 inch pieces of triangular stock in the lower courners of the frount of the fuse, clear back to the wing,,, gives you a lot to sand off to get that round body,
I did not extend the tail, too much work(read that too scared to cut the body in half. I did add 3/4 of an inch to the nose. After sanding it's probably less that 1/2 inch. I hollowed out the nose cone so the battery can sit way forward. There is still a ton of room in the fuse for electronics. Heck I'm using standard servos just cause I need the weight up there. Plan to have a pull-pull on the rudder. The flying tail linkage was easier than it looked in the plans.

[onewingwilli]

I can really get wordy when I want... Here's more

I have used the standard rubberband hook-up on my plane. Boinked my Gental Lady in too often but saved the wing due to the give in the rubber bands.Looks like the nylon bolt set-up may be a bit heavier.
If you can wait for about a month till I get mine in the air I'll post some pictures of the first flight. The real test of my wing tip set up.
Boy, would I hate to see those tips flutter to the ground from the top of the first launch.
Well, enough from me. Let's see some pictures of your bird when you get started. Always love to steal someones finish scheme.

[schrederman]

I really wish I had read all of this before I plunked down 64.99 for a kit. My wood quality is so bad I'm thinking about taking it back to the hobby shop. They probably won't take it back, but I'm going to try. I have NEVER seen wood of this poor quality in any kit before. Some of the dies were sharp and some were dull, so the die cutting is a mixed bag. I am usually not that fussy about kits and such, but this is ridiculous! I should have just ordered plans and let it go at that....

Jack Womack

[onewingwilli]

Tried to upload a slide show but was shot down, i.e. improper file type. Sooo here's some shots the old way

[onewingwilli]

next

[onewingwilli]

Somebody tellme how to show several shots at once
Another

[onewingwilli]

One more

[onewingwilli]

Last All buttoned up

[onewingwilli]

Any questions I'll be glad to help out or explain

[onewingwilli]

A new BOT is born!!!!!!!!!!!!!! Here's a few photos of the finished bird

[onewingwilli]

And Again

[onewingwilli]

The underside

[onewingwilli]

And one more of the bottom

[onewingwilli]

So here's a few stats

1) AUW-55 oz a little heavy I think but who knows?

2)I think that works out to 7.4 oz/sq.ft.

3) My length worked out to 50.5 in.

All this seem a bit high compared to what Dynaflite says the model should weigh but the plane looks and feels good, Hopefully if the wind calms down I'll put her up this weekend.


Now a few questions of Bot owners

Should I hand toss this thing first? Very big plane Needs a lot of airspeed for control. Seems iffy to me but I'll probably give it a try.
I'll send it up a few time on a big high start before I try a winch launch...good idea or bad?

That's it I'll start a new thread if I get some flight photos


I have a lot of other building photos besides the one I showed here, if anyone wants a set I email the whole lot to you in an attached file. Not for the bandwidth challenges let me say.

[KnotEye]

1WW,

Great Job! I gotta say though... that's one funky colour scheme/design! Can you say...'Taxi!'.

I've just started cutting my ribs. It will be a loooong process. I'll keep you posted.

About you test launch. I've always chose a strong toss (from a roof top if you can...with tall grass around). Short easy tosses can actually be dangerous as you have NO time to correct or adjust.

Double Double Check your connections, CG, tail movements,, servo travels... before you launch. Run with it in hand to see how it feels. Once you have some comfort.... GO FOR IT!

Thanks much for the photos.
Cameron

[RCFlybry]

I actually love the color scheme! Looks very nice. I'll look forward to a flight report. I've wanted one of these for years and was going to by the ARF version that just came out but they are out of stock until August. The kit was second in mind but am getting turned off of that now as well due to reports of poor quality wood. Any Idea of where I can order the plans only from?

Bryan

[KnotEye]

Here's the link you want:

RCM Store - Bird of Time plans (http://www.rcmmagazine.com/e/env/0001pOXKgYKMVNglMM102z9/store/store-plans.html?link=/store/store-plans-list-5.html)

The plan # is 751

It takes about 2 weeks to get them.
Thornburg had a great sence of humour went he wrote them.

ENJOY!

[onewingwilli]

Thanks Bryan, I was going for the "Killer Bee" look rather than
"Taxi" but I'm begining to warm to "taxi'. I may end up calling my plane that. Thanks for the idea KnotEye.. need some black lettering now , maybe some checker patterns. hmmmmm?
If we get a calm wind weekend this may be the time for a hand toss. Come on wind gods...

[Daveairway]

Originally posted by onewingwilli
(Snip by Dave)
Now a few questions of Bot owners

Should I hand toss this thing first? Very big plane Needs a lot of airspeed for control. Seems iffy to me but I'll probably give it a try.
I'll send it up a few time on a big high start before I try a winch launch...good idea or bad?



Hi Willi,

First off, Very NICE looking BOT. You have done well!

I do suggest a hand toss to start with. The BOT is really quite easy to launch, just aim the nose at the ground about 100 yards away (do not toss it up, just level or very slightly nose down) . A firm launch is all that is needed, not a mighty heave. If possible, find someone that knows how to throw a glider. Then you can be ready with the down elevator if needed (most do) on the first flight.

Speaking of elevators. I hold a 4 foot ruler under the bottom side of the wing and let it extend towards the tail. Then make sure the stab is level with this. Should get you pretty close.

Also, the BOT is made to "tap" up the winch. No "pedal to the metal" stuff....

Happy Landings,
Dave

PS: I really like the BOT. I am still flying Dave Thornburg's proto-type (that he gave me when he left town) and several others.

[jrgospod]

One point to remember! You can’t let off the pedal on a Hi-Start. If something is wrong you will drag the plane till the contraction of the rubber is finished. On a winch when you stop tapping the pedal the plane releases.

John

P.S. don't ask how I know.

[Les Horvath]

Help!
How do I take the nose weight out of BOT?
Les

[jcstalls]

Greetings,

So Les, your ship is nose heavy? Mmm. Good to hear as to lighten her up. Bad to hear as more work involved in your ARFBOT.
Hope to finish mine before dawn.
I would suppose if I had to I would use my dremel with the flex wand and a good respriator rated for heavy metals.

Before some rocket engineer decides to use a soldering iron to melt it some out, Don't. The fumes are deadly, and the heat would transfer to the glass nose and damange it.

Jared

[Ollie]

Assuming you are using a square battery pack of AA nicad size, you could lighten the battery pack by a half ounce or so. Replace the battery pack with 2/3A size 600KR high capacity nicad cells. To save an ounce or so the replacement could be HR-AAAU 720mAh (AAA) nickel metal hydride cells. The cost would be any where from $8 to $20 depending on the cell and whether you make up your own pack of buy one ready made. It probably would obviate the need to remove lead from the nose. If a new battery pack didn't move the CG back far enough to suit you, then you could move the receiver farther aft under the wing or into the tail cone.

[KevinSharbonda]

Hey Les, hi, I put together a few lightening techniques.... traded the steel control rod for a carbon rod to the rudder...lost some nose weight, used high capacity battery...lost some more, used as little wire as possible for the servo extension...lost some more! With a few other little tricks and some trimming, managed to loose all the nose weight I had previously added on first flights! Still have the hunk that came in the nose though! She really floats and had a great time out Thursday evening floating all over the sky... hope you come to enjoy yours as much as I do mine so far! Good luck-kev

[onewingwilli]

Bryan, here's the picture . Is this the piece you are asking about?

[RCFlybry]

Yes!! That's the one. I was needing to know if it was glued flat to the outer wing panel. I guess that it's kind of an optical illusion as it looks like it's at a slight angle to the outer panel from your picture and others that I've looked at. The plans just say to glue it in place but didn't really specify if it was flat or not. I didn't want to screw this part of the wing up. It's part of what makes this bird look great.

Bryan

[onewingwilli]

Bryan, Yup, just an illusion, it's really flat to the outer wing panel. When it comes time to put the curve in the trailing edge of that piece, I traced the outline from the plans onto a sheet of onion-skin paper, than put the paper over the piece of wood. Then I used a pin to lightly punch tiny holes in the wood along the outline of the curve. I then sanded the wood just up to the small holes. Worked great.

[RCFlybry]

Thanks for the info. and the tips on shaping the trailing edge.
I'll put 'em to use.

Bryan

[Rob Nelson]

Hi onewing..and other BOT builders,
Just ordered the Dynaflight kit..looking forward for the winter build. Have my fingers crossed with resect to wood quaulity. Probably use some contest grade for the rudder anyways. This is a great thread for BOT builders..keep the posts coming.
Most interested to see how your "Bird" flies, in particular, how the three piece wing mod worked out for you. Has anyone else built the kit, or plans, with a three-piece wing? If so, did you utilize the wing joiner bar as onewing did, or would ply bracing be as stong, yet lighter? Notice the ARF version is a three-piece.
Your sailplane looks great..Have fun with it!
Cheers,
Rob

[Daveairway]

Originally posted by Rob Nelson
Hi onewing..and other BOT builders,
Most interested to see how your "Bird" flies, in particular, how the three piece wing mod worked out for you. Has anyone else built the kit, or plans, with a three-piece wing? Notice the ARF version is a three-piece.
(snip'd by Dave)
Cheers,
Rob

Hi Rob, and other BOT builders:

I have found that the BOT really does not mind a “little” extra weight in “most” flying conditions. But, she likes the weight at the fuse, not the tips. If you keep the outer panels light, handles like a Dream! This may sound strange, but the BOT will do rolling circles when the tips are kept light. Also, one of mine has been “abused” with 8 to 10 cells and a 10 oz of motor. She has no clue that it carries the “extra” weight, and I am not going to let the plane know!

The BOT is slippery in flight, and a little extra weight gets you from one thermal to another. BTW: Once, in a desperate moment with 25+ MPH winds at a thermal contest, I drilled holes in the D-Tube and added 2lb’s of lead shot. Out flew the glass ships for time aloft, but…. landing on the spot was another story….

A BOT kind of Guy,
Dave

[BMatthews]

Rob, more than the fin wood weight pay particular attention to the spruce spar stock. You're looking for very straight grain with little or no runout. If there's enough wood try breaking a small bit off the end of a stick or two to see how it snaps. It should show a lot of flex before it lets go. and when it does it shouldn't be a short angled break but rather an very stringy one that indicates very long fiber orientation.

If in doubt get some good hobby shop spruce in the same size and try a couple breaks in that and compare.

It's worth the time if you want to do any winch launces where a ping off the top is an option.

[Rob Nelson]

Thanks for the great tips guys. I'll pay particular attention to the spars.
May just stick with the two piece wing if the BOT likes light tips. I'm just thinking it will be simpler..and lighter at the tips.
Found an interesting web site of contruction photos of a BOT. Don't exactly know what language it's in...Can't understand any of the text, but there are some good photos of the various stages of construction.
http://homepage.mac.com/koichi_takasaki/hang/BOT/BOT.html
Cheers,
Rob

[Raymund Reyes]

Here's a cool BoT page in English :)

I'm personally gonna do a superstrong BoT with a two-piece wing, carbon capped/Ramin spars, kevlar wrapped shear webs andMultiplex rising fence spoilers!!!! :) But I get ahead of myself... :D

http://isoar.ca/~andrewm/rc/bot/

Godspeed and see you on the flipside,
Ray