Your Sig Somethin' Extra Kit - Waiting List Order Source! 
Feeling grounded? We're still flying at Radical RC! 



1905 Wright Flyer 68"

Dummy R-985 Radial 
 Flite Test visits Radical RC 
         Sig Somethin Extra     

 Home2022 DAYTON MODELRAMA  | View Shopping Cart

  1. Whats New >
  2. Kits >

Sig Somethin' Extra Kit - Waiting List Order - Product Image
Click for larger image

Sig Somethin' Extra Kit - Waiting List Order

The new Sig Somethin' Extra has it all - good looks, incredible performance, Sig quality balsa and ply construction and every part in the kit is laser-cut!

This kit can literally be built as fast as the modeler can apply CA glue and accelerator. Fantastic flight performance using either 2-stroke or 4-stroke engines. The aerobatic capabilities of this model are virtually unlimited due to its thick airfoil section and very light wing loading. A perfect club contest airplane.

Kit Features: Balsa and Ply Construction, Pre-Cut Sheet Balsa Tail Surfaces, Durable Aluminum Main Landing Gear, Formed Tailwheel Wire, Molded Clear Plastic Canopy, Full Size Plans, Fast-Building 2 Piece Wing For Easy Transportation, Full Size Plans, Engine Mounts, Sig Easy Hinges, Pushrods, Complete Hardware Pack & Large Decal Sheet.

Wingspan: 51.5 in 1308 mm
Wing Area: 614 sq in 39.6 sq dm
Flying Weight: 4.25-4.75 lb 1928-2150 g
Length: 48.25in 1226 mm
Radio Required: 4 Channel, 4 Servos
Recommended Engines: .40-.46 cubic in (6.6 - 7.5 cubic cm) 2-Stroke, .56-.65 cubic in (9.2 - 10.7 cubic cm) 4-Stroke

Special notes about electric from Dave: This model makes an excellent electric conversion. My first large electric was one of these on 20 1750FAUP Cells. Yikes, I'd love to do another one with modern packs! Here is how I'd do it. Yes, this is same chart as the 4 Star 40, similar weight and wing area. An under recognized yet excellent electric conversion model. Good weight to wng area. A little troublesome to get large NiMH packs into due to the wing tube. However with Lipo's it's super easy to fit the pack. Below are my suggestions for a range of practical power systems.

Setup and Performance Chart
Motor# CellsPropAmpsWatts InRPMThrust oz.Pitch Speed MPHClimb FPMEst. Top Speed
Himax 3522-0990312x641.74698,4706248137753
Himax 3528-800312x1037.44216,9506654126056
Himax 3528-800411x736.65499,7706568167461
Himax 3528-1000312x644.55018,6904964149054
Himax 3528-1000411x5.551.477111,6606185217764
Himax 3528-1000312x644.55018,6904964149054
Himax 5018-530512x830.55728,5606576183963
Himax 5018-530612x840.59119,93075104276673

Estimates based on manufacturers provided constants using E-Calc. High Quality 2100-3000mah used as trial cell in calculations. Presumed model weight of 76oz. @3 cells (added oz for higher cell counts). Actual performance may vary depending on components, accuracy of data provided by manufacturer, quality of battery, ESC, and many other factors.

Temporarily out of stock, pending manufacturer production 

SKU Number: SIGRC76

Radical RC SiteMap  

Questions on this Sig Somethin Extra Kit Waiting? Email us at