Thread Tools
Mar 09, 2009, 11:02 AM
Be Happy, Lower Your Standards
kineticartist's Avatar
Thread OP
Build Log

"Vee" OT Build


Vee Build

The "Vee" is a free flight gas design cir. 1941. It was published in MAN in 1943, but Gene Wallock, SAM librarian, has certified it as SAM approved because it clearly was designed before that. Several versions were made in the development of the design, the engine of choice was a Forster 29, but the plan says it is designed for engines from .25 to .29. The designer also made Class A and Class B versions. I got the plans from the web site www.theplanpage.com which is my all time favorite site for interesting old time model airplane plans and printed them on my home printer.

The designer wanted "…high aspect ratio soaring gas job, stable in any wind." I wanted to have something like that for the SAM Champs 2009. I already have a working Wedgie by Leon Schulman which I really like, but it is not that great in high winds which are a real possibility at Dry Lake Nevada, even in October.

The plans are old time in that the assumption is you don't have a xerox machine available and your computer isn't working so the ribs and motor mount, landing gear are to scale but the big picture is not.

I have made scale datum line plans showing location of ribs and spars in the most schematic way possible. So I have not actually made a plan. As soon as I build this and find everything to be correct, I'll have this scale schematic scanned at Staples and a pdf file made so I can send you a scanned plan (at cost) or just send the pdf file or post it on this forum. The rest of the plan should be downloaded from theplanspage.com web site if you are interested.


I am doing this build in order to help someone else build one, but I'm really new to this old time style of building and not at all and expert. I'm hoping to get some help along the way from some of you more experiened builders. If you want to see a real build, take a look at Tandy Walker's Goldberg Sailplane build. http://www.sam15.org/projectindex.html . This is the finest most elegant example of a build I have ever seen.

I am also going to make this an electric R/C version so I can compete in the ELMR and possibly the speed400 event. The model is suppossed to have an 8 oz wing loading, but I'll wait and see. The big challenge, then is to have a stabilizer with twin fins be R/C controlled. I have a couple of ideas about that and will get to it as I get to it.

I also purchased a used copy of the book "Model Airplane Design and Theory of Flight" by Charles Grant from Amazon,com to see what the designer was reading. I also suspect Leon Schulman had a copy of the book and that both Ralph Ullenberg, designer of the "Vee" and Leon Schulman, designer of the "Wedgie" worked independently of each other without knowing it. They should have done a Google search first.
Sign up now
to remove ads between posts
Mar 09, 2009, 12:39 PM
Be Happy, Lower Your Standards
kineticartist's Avatar
Thread OP

Picture of Vee


I forgot to put up the picture of the "Vee"
Mar 10, 2009, 09:41 AM
Be Happy, Lower Your Standards
kineticartist's Avatar
Thread OP

Vee Build Part 2


Last night I finished the wind half. I had a lot of trouble and it all went back to my determination on having a built in washout. If I built the wing flat and put the washout in later there would have been fewer problems. Furthermore, I'm not that great a builder and the "D" leading edge is fairly new to me.

My reasoning for a built in washout instead of shrunk in later is this: spring back. OT models used the covering as part of the structural integrity of the design. I think this is poor engineering for the simple reason that the covering is never stable. In humid air, an Esaki cover will sag in less than 10 minutes and there goes your strength. I'm using LW polyspan in larger models like this. It is not as much affected by humidity, but it does stretch in time. Furthermore, you can over stretch it when shrinking the first time and it is difficult to stretch back in shape later. If you haven't over shrunk, however, you can shrink it back again, but as it stretches, where is your structural advantage?


However, I live by my mantra: When the going gets tough, the tough lower their standards.

I gave up on the wing tip. The plan calls for a wire edger from TE to LE but I couldn't be sure all was going to fit so I cut the whole business off at the last rib and put in a solid balsa tip. This sure made things easier.

I installed the lower LE covering "in air" although I put the wing down on the plan whenever I could. After it was all glued up I have a washout after all.

I finished the other side of the fuse as well, but there is no point in going into detail about that. I have also decided to install the elevator servo in the stab, so I know how I'm going to finish the tail of the fuse now. I know there is going to be a weight penalty for that and the ratio is 1:3, i.e., for every increment of weight behind the CG you have to add three times as much on the other end of the CG. Lots of variables here, but I get the point.
Mar 10, 2009, 10:35 AM
Registered User
That is one bizarre airplane! Thanks for bringing it to life. Your build is going great.

Jim
Mar 11, 2009, 08:57 AM
Culper Junior
Good build post, very interesting design. This one has had my interest for several years since seeing it in one of my Dad's old mags. Keep up the steam and follow through with a complete build and flight photos .
Mar 11, 2009, 10:14 AM
Be Happy, Lower Your Standards
kineticartist's Avatar
Thread OP

Vee Build Part 3


Last night I did the other wing. Again, the built in washout was a problem, but this time I did more construction "in air", which means off the board. I really soaked the balsa sheet, even using ammonia and attached it to the ribs/spars with thin CA. I didn't fix it that much. As soon as the top skin was on I put it back on the board to let it dry, then repeated for the other skin, putting it back on the board to dry overnight. This seemed to work much better. The soft balsa will deform with clamps and leave marks so I used long angle iron and flat pieces of lead to distribute the weight.

Hard to believe, but it worked. Both wings now have a washout of about 1/8" which is not the spring back point for a neutral wing. I can do fine adjustment with the covering shrink routine if I need to. Tonight I'll put the wings together.

While the wing was drying, I worked on the fuselage. I should have paid more attention to locating the uprights before gluing because they don't exactly match. Oh well, you only see one side at a time anyway.

The fuse is very strong in the triangle format, something to think about in the future.

The pictures show how I lined it all up before I glued it together. Again, I let the tail end be. I'm going to finish that in air as well.
Mar 11, 2009, 07:49 PM
Registered User
Chris Jenkins's Avatar

Strange


Really a strange one...and the building is fascinating...following with a lot of interest

Thanks
Chris
Mar 12, 2009, 02:05 AM
Mmmm...balsa dust!
vintagemxr's Avatar
Great stuff and so cool to see someone build a plane other than the more frequently built Bomber, Powerhouse, Quaker, etc. etc. (Having said that I need to confess to buying a Powerhouse kit recently but the price was right.)

I'm looking forward to seeing your plane finished and hearing how it flies.
Mar 12, 2009, 06:21 AM
Registered User
Airboatflyingshp's Avatar
A bold choice and a fuselage like a Power pylon.... keeping up the triangular fuse theme might you try one of these next? http://www.theplanpage.com/Months/2401/rocketeer.htm triangular but + curves.
Last edited by Airboatflyingshp; Mar 12, 2009 at 06:26 AM.
Mar 12, 2009, 06:46 AM
Registered User
Gluehand's Avatar
...or the charismatic S-4 by Malcolm Abzug....another triangular fuse...
Mar 12, 2009, 09:40 AM
Be Happy, Lower Your Standards
kineticartist's Avatar
Thread OP
I hadn't seen this one. I go back to the plans page again and again and each time find something new to build. Alas, so little time.
Mar 12, 2009, 09:42 AM
Be Happy, Lower Your Standards
kineticartist's Avatar
Thread OP
Hi Gluehand, I really like this design. The legs on the landing gear and the cabin are an interesting attempt to make a flying machine look like a real airplane. They did that a lot in the early days. The "Vee" however, was designed as a flying machine only. I like both.
Mar 12, 2009, 10:04 AM
Be Happy, Lower Your Standards
kineticartist's Avatar
Thread OP

Vee Build Part 4


Last night I fiddled with the wing some more, but started the stab. The big problem is the fins on the ends of the stab. If there were a fin/rudder system then it would be easy. I see two ways to turn the model with R/C. One is to turn the whole stab unit, the other is elevons.

I had decided to install the servo in the stab because there was enough room and use pivot/pushrod system to turn the whole stab/fin combination. I have done this before in rubber models and it works great.

The big problem is weight. The servo I have only weighs 8 gms but still, that would mean as much as 24 gms on the other side of the CG. I went ahead a prepared the stab for this system, but since then I have changed my mind. I think I'll go for elevons. That way both servos can be at or near the CG. My only question is will there be enough elevon to turn the model? I'm guessing yes, because of the long wing and the dihedral.

If not, then my backup would be mounting the servo in the stab and
pivoting the whole unit for turns.

I also have to keep in mind that the R/C control is strictly for steering. I don't intend to fly this like a model airplane around a small field. I want to steer it up to altitude, turn off the power and let it do its thing. There will be infrequent adjustments to trim for the conditions but basically it will be flying with trim control. Then, for landing in the defined space (close to me) or for getting out of trouble, I'll want some serious turning ability.

While I mull this over, I think I'll work on the landing gear and wheel. The plans call for a tapered balsa wheel. Huh? I'll work on it.
Mar 12, 2009, 12:09 PM
If the winds blowin, I'm goin!
CashRC's Avatar
I like it!! looks like a real nice build you have going on there..kinda similar to a wedgy, or this thing here..

Triangle

Seems like there were several models of that era that had a triangular fuse cross-section..
Last edited by CashRC; Mar 12, 2009 at 09:04 PM.
Mar 12, 2009, 12:39 PM
Registered User
Airboatflyingshp's Avatar
Is Sal taibs Powerhouse not virtually triangular aft of the cabin? Im going to check out ben Bucles theres something there on this theme ...I will only add by edit Keeps the thread cleaner.
It was double diamond I was thinking of http://www.benbucklevintage.com/shop...products_id=19 very like the previous entry I made??
Last edited by Airboatflyingshp; Mar 12, 2009 at 01:02 PM.


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Cool OT : Build paper Rossi YZR-M1 scoop075 Motorcycles 3 Jan 22, 2007 08:00 AM