Friday, October 11, 2019

Create RC5-3 shortcomings

The Create RC5-3 is a populair rotator for radioamateurs around the world. It is a mechanically simple device, no bearings, wormwheel and a few gearwheels. Because of the wormwheel there is no real "break" to prevent stress on the rotator. However, this design has shortcomings.

See my first posts about the Create RC5-3:

https://pe4bas.blogspot.com/2017/10/create-rc5-3-rotor-overhaul.html
https://pe4bas.blogspot.com/2017/10/create-rc5-3-rotor-overhaul-2.html

I sold the rotator to PD1RP Peter. He rotated his big 3 element SteppIR with it and his Create was broken. So it was a excellent replacement.

The damage
However, the big SteppIR was too much for the rotator and it just broke the teeth off the aluminium gearwheels in a storm. It is unknown to me why they use weaker aluminium gearwheels instead of steel ones? I guess it is just the prize, although this is not a cheap rotator!

Peter has send me this rotator for repair and also send me 2 other old Create RC5 rotators so I probabely could use parts from them. I discovered the oldest RC5 actually had steel gearwheels and they were still intact. Unfortunately the big gearwheel does not fit into the newer create but the smaller gearwheel does with some modification...

Small mod on top. Filed 1mm
off the edges so it fits below
the big gearwheel.

After inspection of the old Create rotators I saw something else that worries me, it's worn on the axle of the small gearwheel that drives the big gearwheel. It seems this little gearwheel gets a lot of stress. Normally there should be a bearing in the gearwheel to deal with it. But there is non.This rotator is build for a small to medium antennas. Though after my experience I would use it only for small antennas.

In total I had 3 broken RC5-3 rotators now. Luckely there was on axle that had no worn and I used the steel gearwheel of the oldest rotator to replace the broken one. Peter had already replaced the big gearwheel although that one is still aluminium.

I found I am not the only one writing about this kind of damage on this rotator. DL4MW had similair damage to his Create and writes about it already in 2011. It is in German language though. But pictures are universal...

Schaden am Antennenrotor Create RC5-3 (Teil 1)
Schadensanalyse am Antennenrotor Create RC5-3 (Teil 2)

Interesting stuff...

Peter has bought a better rotator now which can easily turn his SteppIR and can stand a big storm, The repaired rotator will be used by the PA6AA contestgroup.

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