August 2006 Vol. 23, No. 8 – R/C - RCSoaring.com

More documents

Recommendations

Info

I ’ve always enjoyed flying RES type models - there’s something to flying a model sailplane set up this way that is both relaxing and challenging at the same time. Over the last year, I’ve had less time to build due to our two year old son and some serious home remodeling projects, yet I needed to update some of my model fleet and find the time to go fly more in the coming flying season. So the hunt was on for an RES model that would fit the bill for club contest type flying, the occasional regional event, and just plain fun flying. After looking at a number of available models, I came to the conclusion that I wanted a model with a more traditional “full” fuselage, not a pod and boom type, and I kept coming back to look at the Soprano RES. The decision was sealed when I had a chance to meet Mark Miller, owner of Isthmus Models, at the 2005 LSF/AMA Soaring NATS and put my eyes and hands on a Soprano. So late Fall I gave Mark a call and placed an order for a Soprano RES. Not long after the phone call, DHL delivered a large box to my doorstep. Inside the box was a very well packed Soprano RES with wings and tail feathers in foam sleeves, well protected with additional bubble wrap, and a fuselage wrapped in bubble wrap along with a hard cardboard sleeve protecting the vertical fin. The miscellaneous small parts were located in a single plastic bag. Also included was a large SOPRANO dry type transfer which could be placed on the wing for all to see. DESCRIPTION: A brief description of the airframe parts is in order. The wing is a 3 piece set up with a flat constant chord center section 39.25 inches long and with a chord of 9.25 inches. The wing is of built up construction with a molded carbon/kevlar weave D-tube placed over balsa ribs and the covering appears to be Oracover that was taut as a drum - no sags to be found anywhere. The main spar is made up of end grain balsa sheer webs capped with approximately 1/16 inch thick carbon fiber spar caps, all of this being neatly wrapped with kevlar thread. The wing ribs aft of the spar are carbon fiber capped and the trailing edge is a carbon fiber molding. The ribs at both ends of the center section are carbon fiber faced as is the bottom of the center section where it will sit on the fuselage. There is a large molded spoiler blade across most of the center section that is live hinged off of the back side of the spar. The center section weighs 12.5 ounces. There are generous balsa webs at the various corners of the wing panel and you are left with the impression that this is a very strong, well built wing panel. The airfoil section used for the Soprano is the MH32 (8.71% thick at 30% chord with a camber of 2.37%). A comparison of the end rib of the center section to a print out of the MH32 using CompuFoil Pro appears to show the airfoil to be fairly accurate except right at and near the trailing edge which is not razor sharp as per the airfoil plot. The outboard/tip panels are double tapered with the inboard sections built much like the center section. The joiner rod is fixed into the outboard panel and is a solid carbon fiber rod approximately 7/16" in diameter. There’s a steel anti-rotation pin located aft on the face rib. The outboard portion of the tip panel does away with the molded D-tube, and the spar is a carbon fiber tube, again all being covered with Oracover. There is a dihedral break where the panel adjoins the center section and again where the outboard panel transitions to the tip panel. The outboard/tip panels weighed 6.1 and 6.2 ounces each and the fit of the panels to the center panel was excellent. The horizontal stabilizers are constructed much like the wing with a carbon/Kevlar D-tube over carbon capped ribs. There are steel pivot rods which plug into the bellcrank within the vertical fin. These two stab halves weighed in at 1.4 ounces complete. The fuselage consists of three parts - the main fuselage, a slide on nose cone and an 4 R/C Soaring Digest
Isthmus Models Soprano RES A review by Mark Nankivil (nankivil@covad.net) August 2006 5
Page 1 and 2: August 2006 Vol. 23, No. 8
Page 3: R/C Soaring Digest Managing Editors
Page 7 and 8: August 2006 7
Page 9 and 10: which two slots need to be cut in t
Page 11 and 12: Soprano RES Span 122 inches Area 99
Page 13 and 14: Maple Leaf Design Encore Fabricatio
Page 15 and 16: Left: Foam horizontal stabilizers w
Page 17 and 18: Left: Grooves are milled in the tab
Page 19 and 20: Left: Completed vertical fin array
Page 21 and 22: Left: Press fit of boom allows easy
Page 23 and 24: Left: Hinge line milled on one surf
Page 25 and 26: eputedly well into next year. I am
Page 27 and 28: senior team has won two flyoff plac
Page 29 and 30: to climb higher than in Canada and
Page 31 and 32: Might sound an obvious question at
Page 33 and 34: Challenge 2006 Dean Thomas (dean@st
Page 35 and 36: Scott Meader and SB/XC, with slight
Page 37 and 38: Team Tiltman 273. Dean Thomas spott
Page 39 and 40: Day 1: Two Hour Speed Task Place Te
Page 41 and 42: Controls: Outer Aileron, Inner Aile
Page 43 and 44: Wingspan Wing area Wing loading Wei
Page 45 and 46: Joe's Wing Geometry Program by Jose
Page 47 and 48: Figure 3. Enter a span of 40", root
Page 49 and 50: Phil explaining how to set up and p
Page 51 and 52: Left: Adam helps Dan Neelands tune
Page 53 and 54: In a thermal, always turn in the sa
Page 55 and 56:
The small lake front dunes of Sauga
Page 57 and 58:
A Michigan Sail-Possum and the adja
show all

August 2006 Vol. 23, No. 8 – R/C - RCSoaring.com

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?