Toronto Electric Model Aviation Club Forum

Toronto Electric Model Aviation Club (TEMAC) => Building / Construction => Topic started by: Michael on November 30, 2020, 07:38:29 PM

Title: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on November 30, 2020, 07:38:29 PM
Although this jet is relatively easy to take off from and land on grass, a few TEMAC members have purchased trailing link (bends back on bumpy takeoffs and landings) landing gear to install on this model.

There is an excellent video on Youtube, but I will post a few photos and comments as I do mine.

https://www.youtube.com/watch?v=2nBOtCUHIuw

Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on November 30, 2020, 07:42:18 PM
The first thing I noticed was that the holes on the new landing gear were not wide enough for the landing gear wires on the plane.

If I'm not mistaken, the wire is 1/8" diameter, and the hole diameter is 3 mm, which is just a tiny bit narrower than the wire.

I will first try to drill out the holes to 1/8".

Also, the video suggests cutting the wires from the retract units to 20 mm or more. I will leave more than 20 mm.

Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on November 30, 2020, 08:36:00 PM
I've re-examined, and maybe the struts don't need to be drilled out.

I'll cut the wire and try to see if things fit.
Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on December 01, 2020, 12:46:19 PM
Wire cut easily with a bolt cutter. (I can lend this to anyone doing the gear upgrade.) I cut the wire just below the spring.

Sanding/filing the cut wire edge smooth.

Test fitting the trailing-link gear; it fits nicely without any drilling.

Remove the gear and roughen/sand/file the wire a bit so the set screws have something to bite into.

Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on December 01, 2020, 04:05:44 PM
Before continuing, remove all hex-set screws from all struts that face into the wing when retracted. Otherwise, your retracts may bind if you test them with the hex-set screws protruding.

Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on December 01, 2020, 04:10:08 PM
main landing gear is installed. There is a right and a left gear. The springs must be on the outside.

The wire is cut, smoothed/sanded, and new struts installed. Once in place, re-install the small hex-set screws (on the inner strut), all the way in. Tighten everything.

When retracted, they sit back in the wheel bay. Since the new wheels are smaller, this is not a problem.
Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on December 01, 2020, 04:13:09 PM
The new nose gear is installed and the small hex-set screws (on the inner side of the strut), are tightened, all the way in.

The plastic and styrofoam will need to be cut and the retract bay slightly enlarged to accommodate the new strut.

I used a new very sharp X-Acto blade, carefully.

Tighten everything.
Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on December 01, 2020, 04:13:54 PM
All done.

Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: Michael on December 01, 2020, 04:18:24 PM
One more thing. The wing tends to crack after a few flights, between the inner flap corner and the wheel bay.

I simply cut a slot, pushed in a small carbon-fiber rod, and filled with epoxy.

Much stronger now.
Title: Re: E-Flite Viper - trailing link landing gear upgrade
Post by: davidk on December 04, 2020, 01:09:52 AM
Nicely done, Michael.  I think this gear upgrade was economical, easy to do, and will benefit landings.  Thanks for the walkthrough.