500 size CH-54 Tarhe (Skycrane) Build

Over the last year I’ve been working on getting my Skycrane up and running. The tail rotor has been one of my major trouble points so far, but I think I’ve finally resolved it. Here’s my lessons learned from the process.

As a note, both the Buamodel Skycrane (and now MH-53 as well) run Trex 500 mechanics, but are big (for a 500) fuselages with stretched tails. Both of mine will be swinging 530mm main blades as the standard 425s looked pitifully undersized. However, this also means the tail rotor diameter needs to be stretched. Both the CH-53 and CH-54 have large tail rotor diameters relative to other helicopters. So, thus the adventure began.

Currently, there is only one 500 size 4 blade tail on the market (STASRC), and it swings 470 size tail blades (69mm). It’s smooth and runs well, but running scale sized standard tail blades (104mm+) was out of the question. So, I decided to pursue other 4 blade tails with wider grips. I ended up testing a lot of options, with results listed below:

PKM 4 blade tail (discontinued)- Initially, this looked good and uses 4 of the standard Align 500 tail grips. However, the grips spindles were misaligned and it was unusable.

DEAO 4 blade tail (discontinued) - Notchy bearings, lots of friction to move.

CNC Helicopter 4 blade tail (discontinued) - Bad pitch slider. The tail grips and hub were true and smooth. I ended up mating this tail with the DEAO pitch slider to create a hybrid that worked pretty well. However, like the DEAO tail, it used ball links to go from the tail blades to the pitch slider. This created a lot more friction in the pitch linkage then I wanted. The standard align tail has a direct bearing supported connection and could be moved effortlessly.

This led me back around to option #1, the STASRC tail rotor. It was smooth and I’ve used it several builds without issues. However, how could I fit larger blades? I decided to buy some 155mm main blades from Microhelis and see if I could make them fit with some trimming. Sure enough, they fit right in, and they are a fiberglass reinforced plastic, so they were easy to cut down to scale diameter and balance! So I finally was able to achieve correct diameter, and an acceptable amount of friction in tail linkage.

Hopefully this saves someone else a bit of head scratching on their next 500 size build!​