F-14 Tomcat Wing Sweep

TedLarson.com

Home -> R/C Airplanes -> F-14 Tomcat -> Wing Sweep

Wing sweep area all done. Ready to start thinking about how I am going to mechanically sweep those wings!

Here is a jackscrew I bought from Janeco through the back of an AMA magazine.

Initial bench testing suggests that with a 9v supply, this jackscrew can supply 20 pounds of force. Here I have it hooked up to a fish scale to measure power.

My initial attempt at building a bell-crank to make the jackscrew work. I am having all kinds of problems getting the wings to sweep evenly with my bellcrank. I ultimately ended throwing this design away, because the uneven sweep issues. Another Tomcat builder in the UK, has built a promising jackscrew system using a programmed PIC and limit switches specifically designed for this Tomcat design. Here is a link to his website, for photos, and even a QuickTime Movie of the jackscrew working in his plane: http://www.freenetpages.co.uk/hp/geoff.sim/

I am very concerned that the wing pivots will be strong enough. So, I obtained some aircraft composites to reinforce them. Carbon-fiber-nomex, reinforced with kevlar cord to keep the nomex from delaminating.

After fooling with the jackscrew for over a month....I have put it aside. Here is my backup plan. 2 quarter scale servos. 12 pounds of torque, each!

Here they are mounted in the plane for some tests. I need to make some aluminum servo horns that are longer than these so I can get the total sweep out of the servos. This is where I am at currently, although some more work is going to be required to finish.

I have remounted them more securely now. I have carbon fiber rods going to the wings. I hoped to complete the maiden flight under this setup.

[Back to F-14 Tomcat main page]