[4stripes]

Had trouble stopping my Hobby Topgun L-39 due to its fast approach speed when there is no head wind so I came up with some servo operated brakes with the help of my father. The landing gear struts have a perfect pivot point just above the tire where the shock strut is bolted to the wheel fork. We used this bolt to attach a lever. One side presses on the tire when the other is pulled with a fishing line attached to the servo. Our servo happens to be the flap servo. When flaps selected UP after landing the fishing line is pulled actuating the flaps. The lever is made from brass strip soldered to brass wire loop. It has some heat shrink over the contact area for extra grip but is not necessary as it melts away too fast.
They really work! I can land very long and apply brakes to stop before the end.
Cheers

[Guest]

Very Clever! Eric

In the past Ive used the traditional methods...Trees, Terafirma and the best one... The grass clipper at the sod field.

[canadianf1pilot]

great idea, I love it when guys post pic's of there inovations....makes it easyer to understand the way it works...and steal the idea ....may have to try somthing like that...

Bill

[davecrash]

Looks like you have done some work to the pivot too, Nice.

[4stripes]

Hi Dave,
the gear legs have been shortened by almost 1". The bracket that keeps the leg straight was drilled out and pushed up the strut (CA'd in place). The shock rod was shortened about 1/2" and a new slot cut. The stock legs are too long only aggravating the force to the retract in a rough landing. With the mods, I really like these HTG struts.
I've changed out the plastic wheels with the newer alloy type as the bushings keep moving in the wheel (even well greased). I'll post some pic's later as they look really scale. The larger tires will be a bonus in the grass.
Cheers

[4stripes]

My father was modifying a couple sets of HTG struts for the next project (F-100 + ???) and took a nice photo showing the various parts (some shortened and others not). Brakes are also clearly shown. You can see the 1" shorter leg in comparison to the original unmodified leg. The leg has to be drilled deeper to just below the smaller hole that mounts the leg to the retract via music wire to allow the shock spring to be deeper in the leg. The spring is shortened slightly as is the shock rod and leg bottom. The pivot point normally threaded on the bottom of the leg is drilled out to slide up the shorter leg (glued in place with CA). The alloy wheels and struts are available directly from Hobby Topgun and I've also seen them here
http://www.hobbywhere.com/index.php?...&product_id=66
The picture is better than a thousand words...
Cheers Eric

PS Need some words... The single wheel "fork" is beefed up with a brass strip bolted to the alloy part. The extra brass fork is held on the axle nut with a short section of brass tubing that just fits over the nut (soldered on the strip of brass). This extra reinforcement was necessary on the heavier Mig 15 (3.7kg) when operating on grass or hard landings. The shock absorbing aluminum rod is beefed up at the bottom pivot section with some brass tubing (bent with side loading before fix).

[Bob Byrnes]

It must be nice to have an engineer/fabricator on the team. Then when you add in the "young son" factor to keep you keen it works really well. Thanks for sharing the tips and advice.