Vialus: New Balsa 34" DLG - RC Groups
Shop our Airplanes Products Drone Products Sales
Thread Tools
Mar 16, 2009, 01:03 AM
Transplant Chey WY from Reno
Thermaln2's Avatar
Discussion

Vialus: New Balsa 34" DLG


Here is my latest attempt to have something new. It is hard to keep building fully bagged planes so this is a diversion.

The name of the plane is called “Vialus”. For us ole farts, this is a contraction of Viagra and Cialus, which keep it up and keep it up longer. Don’t flame me for the play on words!!!

The plane addresses a few items that I have questions about. After going to the German Open, and looking at the past IHLGFs, and everything else, I think we have reached a point of stagnation, meaning everyone is using basically what everyone else is using in the design department. Oh there will be arguments, but I feel that unless we start to really try something absurd, I do not see that there will be any real design changes or challenges. So this is my attempt to add the following areas:

1) Old guys can’t launch as high, but if we can have better sink rates, and use those sink rates, we may not have to launch as high, just close.
2) I want to investigate the Y tail further to reduce tail launch wag, while at the same time keeping the tail smaller for less drag.
3) Explore Y-tail rotational influences.
4) Build a smaller plane that can be accelerated by a weaker arm.
5) Look at reduced drag of less profile areas.
6) Explore simplier manufacturing techniques to use smaller gear.
7) Take advantage of the Vapor Brick and 2.4 GHz Bind and Fly for DLGs. Note here that JR/Horizon has NOT entered the DLG market with a marketable small DLG. Note that this serves notice to them that I see that opportunity missed and if they want to copy my plane, then need to talk to my about designs. Ha, Ha, Ha.
8) I want to have a small molded fuselage that can hold light gear.
9) I want a small plane that I can “carry on” to a plane when I travel. (I am tired of seeing those full sized suitcases in “Coach”!
10) I want to look at subfin torque on polyhedral planes to take advantage of the “propeller effect” first noticed by Dick Barker.
11) I want to explore the Y-tail alignment first adopted by Bruce Kimbal for his Hoosier Daddy TLG Freeflight plane.
12) I want to take advantage of the building techniques displayed by Stan Higginbottom, Jim Buxton, and others on the Freeflight forum.
13) I want to explore the non-use of mylars on small planes for vac bagged layups.


So here is some data on the plane:

Wings are carved, A-grain front LE’s and C-grain aft sections. Fuselage is hollow 1/32 ply, which in the next one will be either molded FG or 1/64 ply. Tailboom is a Super Avia SL boom, scrapped. Tail is 3/32 c-grain with live nylon hinge embedded in fin. The Rx is a Vapor brick, with 110 mah single cell Lipo, changed with the Vapor adaptor. I plan to add a small switch and charging plug. The tailboom is adjustable for incidence. The boom pivots like a Free flight TLG. Controls are 0.025” CF rods in Teflon, elevators and rudder controls. Weight is approx 95 grams (everything), which is definitely too much, but not to bad for a first try. The wings are one piece, bolt on for traveling. The tail will be bolt on later. I have tested the range on my RX with my 9303 to 600 ft by GPS, so I expect that it should be enough for a guy like me with glasses!

I still have to add dihedral braces for strength and FG the breaks. I can sand more of the fuse to get a rounder fuselage. I have not figured out the areas yet.

I have pictures of the build, if there is interest. Hopefully, I will get some stick time on it next weekend. We'll see how it addresses my design concerns.

Enjoy.

Chris
Last edited by Thermaln2; Mar 16, 2009 at 02:57 AM.
Sign up now
to remove ads between posts
Mar 16, 2009, 02:45 AM
Slope Drifting?
Lamborghini12345's Avatar
Very nice I like! Cant wait for flight report!
Mar 16, 2009, 03:04 AM
Team WC2013 F3K
oakman7004's Avatar
WOW, really nice design.

I can see some influences from FF DLG's and I belive this bird will fly great. I hope you can come up with drawing or even better a kit (I'm first in line) for the rest of us mortal persons...

/Jonas
Mar 16, 2009, 03:52 AM
Registered User
Am liking your thinking

PG
Mar 16, 2009, 04:51 AM
Registered User
MGeo's Avatar
Any details on how you shape your wing airfoils and join would be much appreciated.
Mar 16, 2009, 06:48 AM
Throw a glider!
glider90's Avatar

Great job!


Chris, you did your homework on this, looks fantastic. I also like the brick adaption.

Weight is not far off. Our 36" FFDLG's are in the 85 gram range ideally.

Curious, did you skew the stab on the boom as done in FF or glue it on straight?

Eager to hear flight reports, you (easily) beat me to it.
~Jim Buxton
Mar 16, 2009, 12:10 PM
Transplant Chey WY from Reno
Thermaln2's Avatar
Quote:
Originally Posted by MGeo
Any details on how you shape your wing airfoils and join would be much appreciated.
MGeo,

The shape of airfoils has always puzzled me. I have looked over the sanding procedures explained by Dr. Drela, and have looked over the airfoil shapes of the current indoor HLG planes, and see that carving airfoils is more of an art than anything else. I have seen different approaches for airfoils and DLG planforms. For example, the SG series goes to thinner tip section. However, when I try to find out more info of tip airfoil design, the artivles by Dr,. Drela appear to state that modeling of the tip airfoils may not be accurate. So what does that mean? On the other side, Shaper Dave experiments with more cambered tip airfoils, in effect, to try to make more of the inner portion of the wing have lift further out on the DLG span. This is obviously balanced by flutter considerations.

So we get down to what is a good airfoil? Since this ship has a root chord of approx 4.6" we are in the range of the tip chords of 60" DLGs .

That being said, I attempted to use a printout of the Ag16 airfoil for a few reasons. First, it is thicker, so the wing will have more strength. Second, it is undercambered because I think that RC ships can be undercambered while FF ships tend to need a bit more stability and cambered sections have more pitching moment. The Ag16 has better curves than the Ag04 or Ag45 series, in my opinion.

What I did was draw a line at the 25% highpoint and tapered to the TE normally. I then sequentially sanded/planed the wing per the procedures by Dr. Drela. What I got I will post, but I am sorry they are quite out of focus.

If I were doing this again, I would cut AG16 spyderfoam cores and bag them. The airfoil will be more accurate for that, I just cannot get the elliptical planform as nice.

Hope this helps.
Last edited by Thermaln2; Mar 16, 2009 at 12:47 PM.
Mar 16, 2009, 12:37 PM
Tarzanstyle English Sorry
AgoMago's Avatar
Chris
Compliments
As always nice subject full of innovations
We always learn something from others..Thanks to show it.
Ago
Mar 16, 2009, 12:39 PM
Registered User
Mark Drela did some posts in which he calculated the optimal weight for his gliders, down in the 6 oz range, I think. It might be that he'd share his calculations and you could calculate your optimum weight and work from there.

I think this is great that you are trying this. Us old folks need all the help we can get

Your introducing lots of variables, how are you going to tell which ones are positive and which ones are not helpful?

Please keep us well informed. Are you bringing one to Poway?

Gary
Mar 16, 2009, 12:40 PM
Transplant Chey WY from Reno
Thermaln2's Avatar
Quote:
Originally Posted by glider90
Chris, you did your homework on this, looks fantastic. I also like the brick adaption.

Weight is not far off. Our 36" FFDLG's are in the 85 gram range ideally.

Curious, did you skew the stab on the boom as done in FF or glue it on straight?

Eager to hear flight reports, you (easily) beat me to it.
~Jim Buxton
Well Jim, you had to ask the questions before I found out the answers for what I did! I have to say you really influenced me on what I was doing, so thanks! I bought a Stan Buddenbohm plane, and scoured the PDFs you sent me for the Pelicantoo, Turnup, DynoHum and Hoosier Daddy. Stan mentioned that I was in the the wrong company when I told him I had talked to you. Something about "Didn't you listen your mother about who you should be associating with?" was mumbled.

The offest stab was a big question, as I detailed to you in other communications. I did not offset the stab. I did however offset the subfin, LE approx 3/32 to the left when viewed from above. When looking at all the FF designs, the inherent stability required for them is something we try to avoid in some way with RC DLGs. So by keeping the stab straight, I can adjust the zero incidence without having to worry about and balance the induced roll. I used the rudder in two ways. First, I increased the subfin area down so I can induce more "Propeller" torque during launch. Also, by increasing the subfin, I get more balanced wag reduction. The V-Stab is nice because I can pull up elevator without the need to have something spring loaded or having to use some sort of bellcrank to get the stab action. I also do not like flying stabs on DLGs because I think when planes are flying slow, the stab cannot react fast enough to pulling the plane up into a thermal. This may just be my preference. There may be other really good, after the fact, expanations, so let's wait.

And before you ask, yes, the outer tip panels are canted like in FF designs.

The boom incidence uses your DT type mount, and I pass a nylon screw through the boom to fasten doen the boom on the set-screw (black) . the setscrew has a hex head, so I canl loosen the nylon screw, pass an allen wrench through the boom to add/remove incdience, then tighten up the nylon screw. This is done from the bottom. We'll see how this works.

For now, I have to finish this thing. I envy your patience because I am always dinging the soft balsa wing, or brushing the sanding block over the qwrong part of the wing to leave a mark. Uncle Daedalus was awfully patient when he built his wings, and cousin Icarus was more impatient that I have been! I can see why Dr Drela designed his ship to fly from Crete using composites! I want to finish the wing with some light coats of thinned epoxy, sanded between coats. I need to add color, like in your airbrushed designs for help with seeing it. I also want to be able to field repair the wing, so I do not want to use wax finishes. Recommendations?

I was going to go way overboard and add flaps. The motor ESC on the Vapor brick lends itself well to magnetic actuators embedded in the wing. Just full throttle for full landing flap. Would that have been too extreme? It might have added on 10 grams total!

I hope these additional pics help.
Last edited by Thermaln2; Mar 16, 2009 at 12:52 PM.
Mar 16, 2009, 12:44 PM
Transplant Chey WY from Reno
Thermaln2's Avatar
Quote:
Originally Posted by GaryO
Mark Drela did some posts in which he calculated the optimal weight for his gliders, down in the 6 oz range, I think. It might be that he'd share his calculations and you could calculate your optimum weight and work from there.

I think this is great that you are trying this. Us old folks need all the help we can get

Your introducing lots of variables, how are you going to tell which ones are positive and which ones are not helpful?

Please keep us well informed. Are you bringing one to Poway?

Gary
Gary,

I think we can sort out the variables. As for Poway, this one will be coming. I may bring down two more, only these will be composite ships.

The real issue is whether I will have to fight to get them flying right. the nice thing about 2.4 Ghz is that I can bring these down and have friends bind their TX's to the planes, and we can fly them all together.

I wish I had my 60" ship with these features done.

See you there.

Chris
Mar 16, 2009, 07:06 PM
Herk
HerkS's Avatar
Fascinating project Chris. I still love the balsa - Have used a very light coat of Polyurethane varnish stain on my balsa stuff. Adds a bit of color - keeps the balsa beauty and adds an acceptable amount of weight.

What is the approximate wing area?

What do you think the final weight will be after reinforcements - finish etc.
Mar 16, 2009, 08:53 PM
Physics hate's my ideas
GreenAce92's Avatar
dang! everything is razor thin! i love the V-tail and vert stab underneath sweet!
Mar 17, 2009, 05:50 PM
Registered User
Don't get it
Maybe it's the perspective--but the pod on the finished model seems much thinner then the pod in build process.
Is it my eyes or am I just so tired that my sight is failing?

PIG
Mar 17, 2009, 08:41 PM
C4X
C4X
Glider Junkie Beyond Help
C4X's Avatar
Quote:
Originally Posted by POWERGROOVES
Don't get it
Maybe it's the perspective--but the pod on the finished model seems much thinner then the pod in build process.
Is it my eyes or am I just so tired that my sight is failing?

PIG
It took me a while to clue in, but its because of the 'outside the box' thinking, and maybe a little FF influence, but the brick is sitting sideways, not flat. VERY inspiring, Chris! Very nice. It suits the little 3 in 1 unit to sit so inconspicuously and come off looking like a FF glider! I had built a Nano, which was for my PZ brick, but failed to make any design changes to optimize the use of the little guy in such a convenient and efficient way as your ship does. Thank you for sharing this. I will most certainly credit you should I utilize it for my next micro HLG. The Nano turned out to be a disappointing glider. Maneuverable, but not nearly floaty enough to do what I had hoped it would.

You mentioned plans to go composite. Do you think the weight will remain as low? Lower? I don't have the experience to know what weights to expect, but will go with a hotwired foam core regardless. Simply cannot ignore the possibility of a more exacting airfoil. Maybe lightweight tape cover is an option otherwise.

Beautiful glider! Thanks again for sharing


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
I want a new BALSA 3D plane... Ted U 3D Flying 4 Mar 07, 2004 04:04 PM
My new balsa-tailed Slow Stick Zak Parkflyers 6 Nov 03, 2003 12:20 AM
Yippee! New 36" DLG Flying Wing! Videos! efarmer Hand Launch 3 Oct 31, 2002 05:20 PM
New Home Brewed DLG Acer Electric Sailplanes 18 Jan 18, 2002 05:45 PM
New Home Brewed DLG Acer Electric Plane Talk 6 Nov 13, 2001 02:54 PM