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Ground Adjustable Propeller

InsideOut

InsideOut

Well Known Member
Do any of you have experience with the hollow-blade composite Sensenich propeller Van is using on the RV-12? To me it looks like it might be a nice unit. How easy/difficult is it to make changes and adjust to an optimum pitch?
 
Rob,
This prop is not designed for the higher hp. I believe the max is 100 or maybe 120.
 
Supposedly they have an index system built into the hub - you loosen the hub, back the blades off the index, rotate the index mechanism, then snug up the blades on the index stops and retighten - no protractor needed.

The IndUS folks were happy with the Jabiru 330 with the 2-bade Sen composite prop when I talked to them. If the prop works as advertised, then it will be the prop to have.
 
When Van's completes the testing of the 12, I'm sure that they will recommend the best setting for the plane to qualify as a light sport plane.
 
This is what the graduations for ground adjustment looks like on the RV-12 Sensenich prop. The shaft is the pitot tube. Just loosen the bolts, turn both blades (they are connected internally so they turn the same) dial a new setting, and torque the bolts. You can double check the angle with a Warp Drive (or similar) precision protractor, but I have found this set up to be very accuate side to side.

RV-12_Sensenich_Prop.JPG


The prop that comes with the -12 kit has a restrictor plate on it so you can only turn it about 1 1/2 lines. Too much and there is not enough engine, too little and you over spin it. Pretty much right in the middle is a good balance to achieve the 5200 RPM take off minimum RPM called out by Rotax for the 912S. A very cool prop to own.

The amount of adjustment travel (Thanks Marty!) of the prop is 4 degrees. The prop seems to hit the 5200 RPM climb out requirement when you set the prop to full course, then back it off 1.6 degrees. You can double check the angle with a Warp Drive (or similar) precision protractor. This would be a great starting point anyway.

Here is a link to the protractor.
http://www.aircraftspruce.com/catalog/appages/propprot.php
 
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When I got mine, I called Sensenich and said there are 5 notches on my adj prop...I can only get to two...how do I get to the other three. They said, "call Vans!"
 
Peterk said:
When I got mine, I called Sensenich and said there are 5 notches on my adj prop...I can only get to two...how do I get to the other three. They said, "call Vans!"
Click to expand...

I'm pretty sure they added the restrictor plate to match the RV-12 engine, airframe, and LSA requirements. No need to exceed it unless you put a turbo on the 912, but then of course you would have a 914. ;)
 
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I have gotten several calls from RV-12 builders with static RPM of 4600 RPM looking for advice. The setting of the ground adjustable prop should be set in the middle of the adjustment range for first engine start and run up. Static RPM is around 5,000 -5,100 per the building plans should be followed. I'm not trying to over ride the "plans" here just trying to make a post about getting the RPM where it should be for 1st flight as 4,600 RPM is too low. A good climb setting IMHO for the first 5 hours or so is a good thing if you need to do a go around, and to do your required stall work.

Don't spend too much time trying to dial in the exact RPM. The numbers will change a little as the engine breaks in and you add wheel pants, paint, etc..
 
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Next RVator...

I understand there will be an article by Scott in the next RVator on adjusting the Sensenich prop.

Tony
 
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