gschuld
Well-Known Member
I have been thinking about ground adjustable propellers lately. In the quest for a small, lightweight, 100-120hp fast two seater, propeller efficiency is certainly a factor. The idea of being able to taylor the pitch of a ground adjustable prop to the plane is appealing. It allows the ability to fine tune the pitch setting depending on the aircraft's role if one was so inclined(flying locally fairly heavily loaded, flying longer distanes solo at a greatly reduces gross weight, going from a 100hp engine to a 120hp engine, etc).
One logistical issue I have come across is the tendency for the root section of the ground adjustable blades to be, well, round in cross section and projecting an unfavorable profile a good ways out from the spinner. Below is a prop, presumably an ultralight style prop based on the size of the hub, with what looks to be a solid attempt to produce a reasonably good airflow section just beyond the hub.
I suppose that these are custom blades made by Craig Catto, judging by the stickers anyway. I have seen all composite prop blades that neck down from round VERY quickly for ground adjustable props. Obviously, a similar style hub/blade combination suitable for an 0-200 or a corvair would require a larger hub, and therefore a greater overall diameter for the transition from "ugly" to decent airflow. Ideally, I would want a ground adjustable prop that would have a favorable blade cross section by the time it exits the spinner. So I am wondering whether this is feasible without needing to run a absurdly large spinner. If it is feasible, I would be willing to spend a decent amount for a really nice set of efficient composite blades and the best hub out there.
Sensenich Propeller Manufacturing Company - Lancaster, PA
This is a fairly recently introduced Sensenich design. The hub for this 0-200 model is as compact as a hub can be. Say with a 13" spinner, the cross section might not look too bad just outside the spinner face. hmmm
George
One logistical issue I have come across is the tendency for the root section of the ground adjustable blades to be, well, round in cross section and projecting an unfavorable profile a good ways out from the spinner. Below is a prop, presumably an ultralight style prop based on the size of the hub, with what looks to be a solid attempt to produce a reasonably good airflow section just beyond the hub.
I suppose that these are custom blades made by Craig Catto, judging by the stickers anyway. I have seen all composite prop blades that neck down from round VERY quickly for ground adjustable props. Obviously, a similar style hub/blade combination suitable for an 0-200 or a corvair would require a larger hub, and therefore a greater overall diameter for the transition from "ugly" to decent airflow. Ideally, I would want a ground adjustable prop that would have a favorable blade cross section by the time it exits the spinner. So I am wondering whether this is feasible without needing to run a absurdly large spinner. If it is feasible, I would be willing to spend a decent amount for a really nice set of efficient composite blades and the best hub out there.
Sensenich Propeller Manufacturing Company - Lancaster, PA
This is a fairly recently introduced Sensenich design. The hub for this 0-200 model is as compact as a hub can be. Say with a 13" spinner, the cross section might not look too bad just outside the spinner face. hmmm
George
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