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Prop Pitch Setting

mike newall

Well Known Member
Sponsor
We will shortly be doing our props.

There appear to be 3 different ways of setting pitch - the pitch pin supplied with the propeller which has pitch 2 and pitch 3 on it, the wooden pitch gauge supplied by Sensennich and the metal one supplied by Vans.

Does any method work better than the others ?
 
Just use the metal pitch tool with an electronic level per Van's directions. The other two are not exact enough to waste your time on.
 
The pin supplied with the prop seems the simplest and most accurate, just not sure whether it coincides with Van's setting.

I think the pin setting system may be new, will check.
 
Using the pin was the easiest but didn't give me equal pitch on both sides. Using the Van's tool is a bit more difficult but does a better job.
 
In the event you want verify your pitch setting, even with pins, you can use your phone. The iPhone is accurate to 0.1 degrees.
 
Originally I set my pitch using the pin indication. When I checked it with an electronic level they were out almost a full degree between the two blades. I never felt it in any vibration.
 
Thanks for this.

Sensennich suggest using the #4 setting for pin setting, but only supply a #2/3 pin. Did anyone else get that and which one did they use ? I have emailed Sensennich.

Will probably set on the pin as it is easy, then check on the digital gauge to see what we get.

I find it odd that you get a disparity using the pin - it is a precision fit and once knocked onto the stop, can't really shift. Will report back soon, we are a month away from setting the props.
 
Thanks for this.

Sensennich suggest using the #4 setting for pin setting, but only supply a #2/3 pin. Did anyone else get that and which one did they use ? I have emailed Sensennich.

The more important info is which pin does the RV-12 build instructions recommend starting with? That still only gets you in the ball park and as already mentioned, the recommended procedure is to use a measuring tool on each blade.

Blades not at very nearly the same pitch (within .1 degrees or so) do cause asymmetric loading on the prop and higher vibration (proven via dynamic prop balance).

For the gauge pins to produce a precises setting on both blades, everything related to the system has to be very precise (and its not). The indexing pins on the root end of the blades are drilled in a fixture after the blade is built. There are numerous different molds that blades are produced from. These and probably many other things all have an influence on the positioning accuracy. Differences of well over .5 degrees is common (and not acceptable).
 
Not hard to use Van's sheetmetal stamped pitch gage to set blades to within 0.1 degree of each other. Entire process takes less than an hour. For me, based at 1K MSL and flying 3-7K MSL... 71.4 degrees is sweet spot for climb/cruise.
 
Thanks for that Scott and quite frankly that shocks me that the factory recommended setting system with precision machined pin, socket etc is considered not that accurate.

It is easy to reference set the blade using the pin, we will then check using the digital to see what it comes to.

The discrepancy between what Sensennich recommend and what they supply does trouble me slightly, hence the question whether it is a Vans specified setting. They say start at 4 but only supply 2 and 3 in the box. I do see that Van's in the latest revision say start with 3 so we will do that
 
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Thanks for that Scott and quite frankly that shocks me that the factory recommended setting system with precision machined pin, socket etc is considered not that accurate.

It is easy to reference set the blade using the pin, we will then check using the digital to see what it comes to.

The discrepancy between what Sensennich recommend and what they supply does trouble me slightly, hence the question whether it is a Vans specified setting. They say start at 4 but only supply 2 and 3 in the box. I do see that Van's in the latest revision say start with 3 so we will do that

The recommendation of not relying upon only the pins is based on actual experience with many RV-12's (both at Van's and by customers).

keep in mind that the documents Sensenich supplies with the prop are generic. They are not specific to any one airplane. They recommend starting with #4 to assure it will not over speed and will be at least safe for a first flight (amusing you have no other information available to base an initial prop setting on).
If you RV-12 ends up being the same as the majority of them are, if you tweek it for an ideal setting you will likely end up at a setting that is slightly courser than #3 but not as course as #4.
 
Prop Pitch

Just set my pitch
Followed Vans instruction suggestions. Took less than 20 minutes.
Both blades 74.1 !
 
Scott, what is a good number for the tool. I had one but as usual when I need something I can not fine it. thanks
 
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