Isthmus Models

EVOLUTION
The name Evolution implies, at least regarding to Darwin, something is superior compared to it’s predecessor. In this case we have to compare the Evolution F3J with the Stratos 3 which is one of the finest sailplanes of all! Both, the Evolution as well as the Stratos 3 were developed by Marc Schneider from Schneider Modellbau in Germany.

After the great success with the Stratos 3 Marc Schneider decided to improve the Stratos carefully to create a competitive ship for today’s F3J contests. Based on the experiences and development of the Stratos 3 he created the Evolution.

The result is a highly competitive plane for the class F3J, which meets also the strength requirements for the class F3B because the strains of today’s F3J ships are hardly lower than of the F3B planes.

We have the pleasure in presenting you a model, which exceeds the expectations of thermal and allround RC pilots.

The molds for the wings, the body and the elevator unit were made on CNC controlled milling machines, which assures a very high degree of profile accuracy.

For the wing profile we use the approved MH 32 profile and a HN 273 mod. is used for the elevator. The rudder fin has been furnished with a NACA profile.

Based on Marc’s experiences a V-tail has just weight advantages. Though, a disadvantage of a V-tail is that you have superposed control functions of rudder and elevator, which results in unwanted losses during tight circling. That is why Marc wanted to be a trend-setter and one of the first manufacturers of high-end RC sailplanes to offer the slightly higher cross-tail. Design-engineering solutions enabled him to built the cross tail as lightly as a V-tail. This efforts result in perfect circling qualities with minimum aerodynamic losses.
Controls:
The EVOLUTION will be controlled by aileron, rudder, horizontal stabilizer and flaps. Aileron/flap-mix (so called butterfly) will be used as landing aid and glide slope control.
Fuselage:
The body is made of a colored high gloss finished Kevlar-carbon. The front part and the nose cone are made of glass fiber which gives you perfect conditions for altitude recording devices. The elevator and wing is detachable, which makes transportation easy. The push rods for the elevator and the rudder are already installed. The rudder linkage is covered aerodynamically. The tow hook has been installed and can be adjusted stepless for personal preferences. Just the RC components have to be installed and the fuse is ready to go.
Wings and Stabilizers:
The all moving tail which is produced in GRP/CRP is mounted on a 8.0 mm carbon rod. You can choose a different color scheme for upper and lower surface for better visibility. Your color choice will be without extra cost, please give us your preference when you order your ship.
The wings comes in three parts, and together with the stabilisers has been moulded in CNC milled forms in modern sandwich method. As materials we use GRP, CRP, Rohacell (very firm yet lightweight foam) and Herex. The carbon version is made entirely from CRP.
Two square shaped joiners connect the middle part of the wings and the wing tips, position fixed by two pre-installed pins. To secure wing tips use film tape.
The ship comes with all (clevises and control horns) linkages and carbon push rods installed. The linkages to flaps and ailerons are aerodynamically covered (completely closed). All control surfaces are mounted gap free. The EVOLUTION flap and aileron are bottom hinged, so you get a closed and sleak wing bottom which lowers drag.
We offer EVOLUTION in These Versions:
GRP: wings and stabs in GRP with carbon spars, fuse in GRP and CRP with Kevlar reinforcements; vertical stabiliser with integrated rudder in sandwich construction; fixing, linkages, tow hook in fuselage installed, ballast tube supplied
Full Carbon: wings all carbon; fuse and stabs as in GRP version
D-Box: D-Box in carbon, aft of wing in GRP (less weight than the full carbon version) fuse and stabs as in GRP version
Colors: white, red, blue, yellow
Basically you can get every color scheme, just send a drawing like you see your ship! All EVOLUTION models are shipped with control mixing instructions, so even pilots who never flew aileron and flap model mixed soon will be familiar with our product

Span: 3330 mm
Length: 1550 mm
Airfoil: MH 32
Flying Weight: 2100 - 2200 g

Aspect Ratio: 16,62

The Evo XL is the slightly bigger, yet a lot more dynamic version of the Evolution.
We are proud to be able to offer to you this high-quality-model. The EVO XL was designed by Marc Schneider, while the wing geometry and airfoil blend has been optimized by the recent European F3J–champion, Philip Kolb. That’s how this splendid F3J–competitor emerged, which also features superb F3B–characteristics and slope-capabilities.
With the newly developed airfoil blend (MH32 to PK321–325) flight performance and dynamic characteristic improved drastically. By the use of modern carbon fabrics the airfoil thickness of 7.5% won’t be of any disadvantage for the structural integrity.
Of course the moulds have been produced by CNC–machinery for absolute precision and airfoil accuracy.

Controls:
The EVO XL will be controlled by aileron, rudder, horizontal stabilizer and flaps. Aileron–flap-mix (so called butterfly) will be used as landing aid and slope control.

Fuselage:
The fuselage is moulded with a glossy surface in carbon–kevlar–fabrics;. The all–moving–stabilizer can be removed for easy transport. The push–pull rod including all mechanics for the stabilizer has been already mounted. Wing mount and electronic compartment are epoxied in. the nose cone just slides over the front. The tow hook has been installed and can be adjusted for personal preferences.

Wings and Stabilizers:
The all–moving–tail which is produced in GRP/CRP is mounted on a 8.0 mm carbon rod. You can choose a different color scheme for upper and lower surface for better visibility. Your color choice will be without extra cost, please give us your preference when you order your ship.
The wings comes in three parts, and together with the stabilizers has been moulded in CNC–milled forms in modern sandwich method. As materials we use GRP, CRP, Rohacell (very firm yet lightweight foam) and Herex. The carbon version is made entirely from CRP.
Two square shaped joiners connect the middle part of the wings and the wing tips, position fixed by two pre–installed pins. To secure wing tips use film tape.
The ship comes with all (clevises and control horns) linkages and carbon push rods installed. The linkages to flaps and ailerons are aerodynamically covered (completely closed). All control surfaces are mounted gap–free. New: the EVO XL flap and aileron are bottom–hinged, so you get a closed and sleek wing bottom which lowers drag.

We offer EVO XL in These Versions:
GRP (glass–version): wings and stabs in GRP with carbon spars, fuse in GRP and CRP with Kevlar reinforcements; vertical stabiliser with integrated rudder in sandwich construction; fixing, linkages, tow hook in fuselage installed, ballast tube supplied
CRP (carbon–version): wings all–carbon; fuse and stabs as in GRP–version
D–Box: D–Box in carbon, aft of wing in GRP (less weight than the full–carbon version) fuse and stabs as in GRP–version
Colors: white, red, blue, yellow
Basically you can get every color scheme, just send a drawing like you see your ship! All EVO XL–models are shipped with control mixing instructions, so even pilots who never flew aileron and flap model mixed soon will be familiar with our product.

Span: 3460 mm
Length: 1600 mm
Airfoil: MH32 / PK 321-325
Flying Weight: 2150 - 2300 g
Aspect Ratio: 17,15
Wing Area: 69,82 dm²
Hor. Stab Airfoil: HN 273mod.
Hor. Stab Area: 7,01 dm²

Isthmus Models is proud to reintroduce the Mini Bird of Time designed by Mark Smith. The Mini Bird of Time is the answer to the question asked by many R/C sailplane pilots, “What can I build that is not a fragile blimp, that can be flown in both calm and windy days, yet won't have the flight characteristics of a brick outhouse?”

We think you will agree with us when you see your two-meter Mini Bird of Time “scoot” up to the top on tow, streak off to a thermal, then slowly circle up and up until it is a mere speck against the clouds. If the plane has drifted with the wind, as it circled in the thermal, you will be pleasantly surprised by the way Mini Bird of Time can penetrate the headwind and return to the launch area.

Can be built with either an 8% or 11% thick airfoil. Can be built with as a one or two piece wing.

Span: 2 meters
Wing Area: 609 Sq. In.
Weight: 26 Oz. Depending on builders skill and radio used.

Isthmus Model Co. is proud to announce a full laser cut kit for the Mirage. The Mirage was designed in the late seventies by Blaine Rawdon for competition flying, with emphasis on duration and spot landing tasks. It is eligible for both Nostalgia and RES competition.

What makes the Mirage special is it's configuration. The most important feature is the airfoil. It is a thick, low camber airfoil, that is, a semi-symetrical section. This airfoil is responsible for the performance of the design. The wing center section is a flat continuous panel to avoid the weight and complication of a joiner or wing rod. The fuselage is an open box section all the way to the rear so that the stab has a wide base and so that the fuselage is very strong for it's weight. The rudder is offset so that it may tie in with the fuselage efficiently. The stab has a single sided elevator which is lighter and cleaner. Care was taken to see that the structure is strong enough everywhere but not overly strong anywhere. This leads to a lot of tapered structural members and a design that is strong for it's weight.

Span: 112.5 Inches
Area: 915 sq. in.
Weight: 35 oz.

Kit contains:

1. Full laser cut parts pack
2. All necessary wood to complete the kit
3. New 2 page plan set
4. Complete hardware pack
5. Vacuum formed canopy
6. Illustrated instruction manual

The strong points of the Mirage are:

1. Ability to fly in the lightest lift
2. Wide speed range with the use of ballast
3. Precision spot landing capabilities
4. Hands off flying characteristics
5. Straight-forward construction technique

Isthmus Model Co. is proud to provide a laser cut parts set for the Mirage in it's original form. This short kit contains the hard to cut shaped parts such as ribs and fuselage formers and sides. It is intended for the builder who wants to supply their own stick and sheet wood. The Mirage was designed in the late seventies by Blaine Rawdon for competition flying, with emphasis on duration and spot landing tasks. It is eligible for both Nostalgia and RES competition. A plans set of the original Mirage is available in the Accessories section.
What makes the Mirage special is it's configuration. The most important feature is the airfoil. It is a thick, low camber airfoil, that is, a semi-symmetrical section. This airfoil is responsible for the performance of the design. The wing center section is a flat continuous panel to avoid the weight and complication of a joiner or wing rod. The fuselage is an open box section all the way to the rear so that the stab has a wide base and so that the fuselage is very strong for it's weight. The rudder is offset so that it may tie in with the fuselage efficiently. The stab has a single sided elevator which is lighter and cleaner. Care was taken to see that the structure is strong enough everywhere but not overly strong anywhere. This leads to a lot of tapered structural members and a design that is strong for it's weight.

Span: 112.5 Inches
Area: 915 sq. in.
Weight: 35 oz.

Parts set contains:
1. Wing ribs
2. Ply wing joiners
3. Ply joiner box sides
4. Fuselage sides and doublers
5. Ply fuselage formers
6. Ply canopy deck
7. Vacuum Formed Canopy
8. 2 Page Plan Set

The strong points of the Mirage are:
1. Ability to fly in the lightest lift
2. Wide speed range with the use of ballast
3. Precision spot landing capabilities
4. Hands off flying characteristics
5. Straight-forward construction technique

Wing kit for our Mirage. Included are all ribs, joiners and joiner box parts.

he ZEPHYR family of sailplanes were designed by Bob Owens. With his permission Isthmus Models is proud to offer them to the public for the first time in kit form. All members of the ZEPHYR family will consist of the finest quality wood and hardware as well as the accuracy of laser and machine cut parts. The family will consist of 5 different versions, all of which retain the fine flying characteristics and ease of building of the originals.

The ZEPHYR II is our 1.5 meter hand launch version. First seen as a plan in the May 1981 Model Aviation, it was one of the earliest hand launch sailplanes available. It has been completely redesigned by Isthmus Model Company to be more in tune with the modern hand launch sailplane. The wing has been stretched to the full 1.5 meters and the fuselage is longer in the forward section to be able to balance with today's lighter radio gear. It retains every bit of the beauty and grace which the 1981 version had. The standard kit weighed in at 7.5 ounces with 2 HS-50 servos, a Hitech 555 Rx without the case and a 4 cell 110 mah battery. It's combination of Drela AG airfoils and optimized wing planform provide outstanding flight characteristics.

Wing Span: 60 in.
Airfoil: Drela AG36-35-34.
Weight with Micro radio: 7.5 to 8oz.
Radio: Mini receiver & 2 Micro servos.