Jump to content

Recommended Posts

Posted

Hey gang,

Yesterday I took my 201 to Marianna Florida (about a twenty minute ride, by the way) and had the rebuilt prop dynamically balanced by Neville Aviation.  (They were referred to me by the prop shop.)  There was an appreciable (way more than just "noticeable") reduction in the vibration since then.  Thought I'd give you guys some details, and of course, some of you might want to share your thoughts and comments here as well.

The process was extremely interesting and they did a great job of explaining things-- I had noticed during initial engine break in at 65% power that the vibration was worst at 2400 RPM, so of course, that's the speed we used to measure and "fix".  The fix for mine was pretty interesting; one of the Hartzelle scimitar blades had two thin weights on it that the prop shop had used to static balance the rebuilt prop, the other blade had none.  After running and measuring, we added weight as the computer indicated and got the prop "better", but Lee at Neville eventually took one of those static weights off, and added a VERY small weight in another position (a bolt and small washer strategically placed) which really did the trick.  The only difficulty we had during the process was in positioning the airplane to properly read the reflective tape while sitting out on the ramp.  No big deal.

I had never wanted to spent the money on that before, but with a rebuilt engine and prop I thought it prudent to see if we could smooth out most of the vibration.  Took a while to set it up and measure, and the actual balancing steps were simple addition and removal of weight. But these guys also work on helicopters rotor balance (these guys are former Army and Air Force aviation) and their rotor blade balance expertise showed.   MUCH smoother climb and cruise at all settings when they finished two hours later.  Since I know you’re going to ask, the cost was $400, which was more than I wanted to spend for two hours labor, but then, I realized I wasn't paying for labor, I was paying for their equipment and expertise.

Oh, and in case some of you may be wondering why I had an engine rebuild (I only had 1050 hours on the engine), you may remember that last year I had loaned my airplane to a young CFII who wanted to get some more "complex" hours so he could get a job with the airlines, I had loaned him my plane provided he get on my insurance, and he reported that he had a "very light" prop strike in an airport in the other end of the state.  Of course, in digging into it later we found out that it was not what he reported, and I had to do a full tear-down rebuild on the engine.  Plane was down for over ten months, mostly waiting on the engine case shop in Tulsa.  (No good deed shall go unpunished, right?....:o.)

  • Like 1
Posted

@jetdriven just did mine. It wasn’t bad beforehand but I’d had an engine done and prop overhaul and RPM has a pretty compelling flat rate on the dynamic balance so I figured I’d give it a go.

The balance is done at a specific RPM (2500). I noticed it being a bit smoother at 2500. For some reason it seems same or rougher at 2700 on takeoff but I don’t spend much time at that RPM. Can’t say things are one but quieter but it does feel a little smoother. I think because I fly LOP a lot, there’s other factors at play in terms of rumbles and vibrations. But at least the prop is no longer contributing.
 

I do appreciate Byron’s flat rate charge for the balance. This way regardless how long it takes you know what you’re in for. They got it from a 50 value to virtually zero on the vertical axis. Took taking the spinner off and adding/subtracting weights like 6 times.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.