Happy Hartzell

Engineering is soo cool – whilst most would find this kinda boring and yeah, its just a bit on a plane, Sarah Joy made a great point that many people do not realise the amount of development work and effort that goes into the hundreds of assemblies and parts that make up a plane. Here is one such bit, one of the simplest constant speed propellers/hub you will see on small 2 or 4 seater aircraft.


I get to see lots of plane bits, but not that often a full propeller hub, in bits 🙂 this one was a unserviceable and had all the bits from the last overhaul. So whaddya do with a Hartzell Propeller which you have in bits, a pair of verniers and a few spare hours? you model it of course and turn it into a animated mechanism. 🙂
well the spare hours is a bit of a lie, I really don’t have those, but did spend a couple of late nights on it 🙂

It’s a non feathering HC-C2YF series propeller hub. Its still a bit of work in progress, but getting there, I need to model the propellers properly, the root sections are ok, however I do not have a propeller and to be honest, I am not sure whether that would help, modelling the airfoil section with the twist and profile is fairly tricky without some design data and thats going to take more than a few hours methinks. In the meantime, its not just some junket model, its pretty well spot on even has the casting draft angle on the hub halves :). I am pretty sure the hub halves would be machined sand cast items (or forged) prolly the latter.

I will get a few photos of the actual part assembled so it can be compared to the CAD model in the meantime, here are a bunch of rendered shots and the animated part, notice the simple, yet ingenious way the translation movement of the pitch change rod (the axle looking thingy) is turned into rotation on the blades (and changes the pitch).. no c’mon and tell me that engineering is not cool 🙂



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