RV-10 Governor Clocking Angle

Hi guys,

I could have sworn that I saw a post on here a year or two ago that had an actual value for the proper governor arm clocking angle for an RV-10. Don't know if that angle changes based on the particular governor used. I am looking to get in on the PCU-5000 group buy, and would like to specify the proper angle.

I know that the angle can be adjusted in the field, but why do that if they'll set the angle at the factory for me?

Thanks for any info, hints, or links! I have come up empty with both the VAF search function and google.

Varies

The angle varies based on the control cable routing and travel. (Quadrant vs Knob)
It literally took less than a minute to adjust in my case.

That's interesting, I was under the impression that the cable came through the air ramp at a fixed location, which would imply a fixed angle to me if the cable is mounted to a fixed bracket below.

Thanks for the info.

not a fixed location

I had to drill the hole in the ramp and locate the bracket to hold the cable. Depending on the length of the cable housing the approach angle and thus the location could vary from almost straight up to perhaps as much as 45 degree approach.

My guess is that there is not a lot of variation in builds (someone with more experience looking at different RV-10s might answer that). But for me with a quadrant located on the tunnel cover, the stock cables (supplied by Vans) took a lot of trial and error to fit. I also had to modify the angle of the stock bracket to fit my routing. Based on that I am guessing there is at least some variation of the cable angle and thus the sweet spot/angle for the attachment arm angle.

On my installation I had to reverse the arm almost 180 degrees from the shipped position to get the correct direction and travel. It only took a few minutes to accomplish at most.

If you install air conditioning in your 10, the prop cable has to be routed over the top of the engine, as the compressor sits below the inlet ramp where the construction drawings show the cable being routed.

Control level rotation

I was going to wait until my engine was installed, but thinking about getting in on this also.

What about the Control level rotation? Clockwise vs counter clockwise? I imagine most/all 540's use the same..

scorwin said:

I was going to wait until my engine was installed, but thinking about getting in on this also.

What about the Control level rotation? Clockwise vs counter clockwise? I imagine most/all 540's use the same..

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I would suggest to wait until the engine is mounted and the baffels are fabricated. This way you can adjust the are perfectly for your build. If you do it based on a published angle, odds are, you will just have to readjust it later.

There is a chance that you?ll have to tweak it once you start flying as well. My travel wasn?t perfect and i had to hold my prop lever to get a full 2700 RPM, the thing that will take you the most amount of time is doing the safety wire after adjusting it. It?s really no big deal

cderk said:

There is a chance that you’ll have to tweak it once you start flying as well. My travel wasn’t perfect and i had to hold my prop lever to get a full 2700 RPM, the thing that will take you the most amount of time is doing the safety wire after adjusting it. It’s really no big deal

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Points taken from everyone. Sounds like some adjustment will be necessary. I'll probably specify an angle of 135 degree based on the FWF construction drawings.

As for the rotation, here's what the FAQ for their spec sheet says:

Control Lever Rotation. Do I need Clockwise or Counter-Clockwise?
Depends on where your control cable attaches to the lever. The lever rests against the high RPM/low pitch stop,
therefore when trying to determine this, imagine how the lever would rotate as your pull the prop control out,
toward a lower RPM. Whatever the answer is (clockwise or counter-clockwise) is what you would put on the form.

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From that, and from photos and FWF construction drawings it looks to me like the choice here is counterclockwise. Can RV-10 builders confirm? Should be the same whether quadrant or push-pull controls, I think.

Clockwise

Mine is clockwise rotation when looking straight at the arm side. The quadrant I used moves the cable in the same direction as the lever, i.e. forward with the lever extends the cable end.

leok said:

Mine is clockwise rotation when looking straight at the arm side. The quadrant I used moves the cable in the same direction as the lever, i.e. forward with the lever extends the cable end.

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Yes, but their specification is to tell them which direction *reduces* the control position. In all the photos I've seen, the cable is at full extension when the engine is shut down, which most people do with the prop control full forward. It also makes sense that pushing in the cable would extend it, causing a clockwise rotation of the arm.

I would take this to mean that rotation to reduce prop speed would be counterclockwise.

Am I missing something?

You are correct. Sorry if I was misleading. Full forward lever/cable position is high RPM and clockwise rotation. Full back lever/cable position is low RPM and counterclockwise.

leok said:

You are correct. Sorry if I was misleading. Full forward lever/cable position is high RPM and clockwise rotation. Full back lever/cable position is low RPM and counterclockwise.

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Thanks for clarifying!

I used 225 degrees, counter clockwise, oil pressure to increase pitch, 2700 take off RPM, drive ratio 947:1

This is for a lycoming thunderbolt IO-540 for my RV10.

My angle was off a bit, but it was close enough.