Originally Posted by jrgospod

Got a question on the building and strength of V-stab and rudder of the Paragon tail. Do you think it is overbuilt? It shows using ¼” x 3/8” stock to build it, but I’m thinking of using 3/16” x 3/8” stock to save weight. The thinner stock seems strong enough and it is the vertical, not the horizontal, so launch stress should not be a factor. Open for your thoughts. Thanks.

John

If I had to do it again, I would do something stronger on that post that runs the height of the vert stab (that attaches by the rear of the fuselage). Mine has cracked a few times. This post gives the stab strength attachment to the fuselage. In my case, this is where I added the bolts to the removable tail. Perhaps laminate carbon to it... Not sure. But that is one area I would try to strengthen.

Otherwise it might be OK to reduce the thickness of the wood, but you generally want it thiner towards the back anyway and that post is a load carry post, so keep that in mind.

Ryan



Ryan

John,

First, my disclaimer, I am NOT an engineer, I usually build (and sometimes modify) by using the TLAR method.... you know, "That Looks About Right". On to your question. I don't think going with thinner material would adversely affect anything on the vertical stab, however if weight is your concern, it's a Paragon, for heavens sake! We're not talking about a few grams making any significant difference here, like it does on smaller HLG and DLG's, where every tiny bit is an issue. I'm sure you'll be fine going with the thinner wood, but I seriously doubt you'll gain any noticeable advantage in flight. My 2 pennies.....

Cheers!
Rick

arukum17.
Morgan's are really nice cars. I used to own a cherry +4. Wish I still had it.
BTW, I'm almost finished with a Grand Esprit, it' has a 134" wing so I know what you mean about room to transport. My wings are two piece????
Good lift to you.
SkipinHouston

I must add my 2 penneth about the morgan. Never owned one but would love to have done so. For those of you over here (USA) that don't know what the Morgan looks like, it resembles a Lotus super seven. When I lived in the U.K, these two cars were put up against one another. Arukum17, years ago, my Dad worked on vintage cars. One of them was a Morgan. It was a three wheeled (two front, one rear) vehicle with a JAP motorcycle engine on the front where your grill is. There were several Model T Fords and one that was entered into the London to Brighton rally every year. It was a modern vehicle at production compared to the others in the London to Brighton, a 1902 DeDeon Buton. On the subject of the size of cars over there, gas is the deciding factor. I just had family here for a visit, and they told me that "petrol" is now one Pound ($1.70-$1-80) a Litre. At almost 5 litres to the US gallon, we would be looking at close to $8.00 per gallon, or more. Why mostly small cars, survival.

Keith

Arukum17,

Build your Gentle Lady and fly it with pride. You will have control (hopefully) of one of the many teeth cutting sailplanes out there. Enjoy it, it will teach you and serve you well. Plenty of time to go to the Paragon, Riser 100 ( my ship along with the GL), Windfree, Winddrifter, et al. fwiw.

Keith

Well, thanks for the input everyone. I built the V-stab and rudder with the reduced thickness of the stock. It seems to be quite strong. Now for the H-stab and elevator. I am adding some ply capping to the center of the H-stab and adding a lower spruce “keel” that will lock into the fuse and make it removable. I did the same thing on me HOB 2X6 and it has worked out fine. I use a “Keel”/ (key and notch) structure with electrical ties to hold the assembled one-piece vertical and horizontal tail to the fuse. It seems to capture the tail well and is easy to remove and reattach. I have attached some pictures so you can see how I have done it on the 2X6 if you are interested.

John

Top hold down block.

Side view of top block and tie going thru fuse.

Rear V-stab vertical riser strapped to back of fuse.

Side view of rear of fuse with tie going thru fuse.

Originally Posted by rdwoebke

If I had to do it again, I would do something stronger on that post that runs the height of the vert stab (that attaches by the rear of the fuselage). Mine has cracked a few times. This post gives the stab strength attachment to the fuselage. In my case, this is where I added the bolts to the removable tail. Perhaps laminate carbon to it... Not sure. But that is one area I would try to strengthen.

Otherwise it might be OK to reduce the thickness of the wood, but you generally want it thiner towards the back anyway and that post is a load carry post, so keep that in mind.

Ryan



Ryan

My last 2 Paragons had 1/8X1/4 balsa stringers added to the tail feathers. One on each side of the vertical fin for a Diamond profile. The improvement in footing and torsional resistance because of the increased base area and extra spar support is excellant, and well worth the small weight increase.

The horizontal stab had the stringer on the underside for a 1/2 Diamond profile. Stiffness increased tremendously. Both vertical and horizontal fins had their chords increased by 1 inch to improve handling when flown without ballast.

Technically: The empty Paragon is a floater and CG tends to be a bit forward. The tiny inverted MCL actually offsets the small download better than a flat plate. Speed runs are on rails - stabilizing the antics of a plump profile with large amounts of ballast - and tail surfaces that are not whippy.
http://www.rcgroups.com/forums/showa...d=930691&stc=1

Histarter,

Thanks for the comments. It’s good to know that it helps with the “footing and torsional resistance”. I figure with making the tail removable I will always have another shot at getting it right if I don’t like the results.

The plans I have show optional ¼” tri stock applied with epoxy at the base of the V-stab and on the bottom of the H-stab next to the fuse. I had planned to use both. That is part of the reason why I used the smaller thickness stock for the V-stab. I figure that the smaller Vstab stock will offset the weight of the tri stock.

John

Definately install the tri stock!

Mine has balsa stock sanded triangle on the sides of the fin too. Forgot to mention that. Is that not in the design?


Ryan

Has Pierce sold the Paragon rights to MZ-Modellbau?
Has anyone built this version - are the instructions in English?

Slobod has not sold rights to MZ-Modellbau. He was shipping boxes of the kits at one time but stopped due to manufacturing/shipping considerations. The German company decided to build them on their own when they couldn't get the kits from the US.

Just phoned them up - they do have the Paragon in stock!!
Not sure wether the kit includes detailed instructions/plans/complete hardware as the person on the phone spoke very basic English and I speak zero German...

Questions:
- Where can I obtain plans for the Paragon? (in the event the kit has no plans!)?

- Where can I obtain the clearest available building instructions for the Paragon? (in the event that the english instruction they are sending over turn out to be too basic for me)

http://www.rcmmagazine.com/e/env/000...ore-plans.html
"Plans for each construction article featured in R/C Modeler Magazine."

PARAGON
Our Price $14.50
by Ed Slobod,

118" span, 1080 sq. in., 2 ch., built-up balsa, plywood, and spruce, two sheets 27" x 52", 34" x 52", Issue: RCM 1-76

And

MIRAGE
Our Price $14.50
by Blaine Rawdon,

112-1/2" span, 915 sq. in., 2 ch., built-up balsa, plywood, and spruce, two sheets 22 -1/4" x 50-1/2", 32" x 49-1/4",

Issue: RCM 2-79

arukum17,

I used this link to order my Paragon and it came with full plans and instructions.

http://home.comcast.net/~bsli40/Specials_page.htm

John