Prop Balancing

[170C]

What would be a reasonable price to pay for having a prop balanced on a C-170 with 0-300 engine & stock prop? Would prices be lower/higher in central US (here in TX as an example) compared to east or west coast? I know I missed out on a bargain balancing at the Lancaster, PA convention because I had to go back to Johnstown to get my plane due to it being weathered in there and the prop balancing took place while I trudged back a long way on a less than good turnpike. But that was a long time ago & prior to an overhaul which would probably have resulted in needing a rebalance anyway. Don't now remember what the cost was. Most who have had their props balanced say nothing but glowing things about how much smoother their engine runs after balancing the prop. I don't know that mine needs balancing and I haven't had any first hand experience flying or riding in a 170 before and after its having been balanced. One would hope those who have good things to say about the balancing do so because they truly do experience a difference & not because they spent $$ to have it done.

[1SeventyZ]

I just had mine done back in June, and paid about $180. That was the $75/hr shop rate, and it took me and the A&P a little while to dial it in. Engine cowlings must be removed. The Chadwick really helps, but there is some voodoo and luck to it as well. It is a great procedure, both from an operational and preventative standpoint, and it's still worth it even if you have to pay more than that.

Make sure you have a healthy battery. I swear we restarted the engine 20 times, between weight changes based on the Chadwick recommendation.

[Brad Brady]

Dinamic balancing is the only way to go.....I can ballance a prop on the knife edge balancer that I devloped......But it is static......a chadwick will tell you what the engine is also doing........Brad

[flyguy]

Frank I expect you mean to be at The Reklaw October fly-in. Their page is posting a "Prop Balance" the Thursday of the Reklaw fly in. I have no idea whether it is a static balance or machine. Here is the link http://www.reklawflyin.com/
GAR

[markeg1964]

You might check your local EAA chapter. Our local EAA chapter (105) has a dynamic balancer that members can use (actually they help you use it) on member planes for I believe $20 plus supplies. I have not taken advantage of this but have thought about it.

[GAHorn]

Frank, as Ol'Gar mentioned, the guy at Reklaw will be doing dynamic balances, and last year he was doing 170's for $175 I believe.

[170C]

The guy at Rekaw is charging $250, which appears to be more or less in line with others. Obviously no discount for being @ Reklaw. Found out our EAA chapter is looking to purchase one of the Chadwick units and will let members use free & charge non members. I think I will wait and use this one, but I have had several conversations w/ folks that had theirs balanced and all seem to think it helped the smoothness of their engine/prop. Thanks for the input.

[1SeventyZ]

As for the increase in smoothness before and after, the difference was admittedly difficult to ascertain for me. It seemed a little better. According to the Chadwick, we got it from .36 IPS out at 2000 rpm (.44 at full static!), down to .12 IPS. I was happy with the smoothness before, but wanted the dynamic balance to see if it would actually get smoother. And the benefits of decreased wear on engine internals of course...

I'll mention another tidbit for anyone chasing a prop-related vibration: Double check that your prop is indexed properly to the crankshaft. While facing the front of the engine, with the top dead center mark on the crank flange at 6 o'clock, prop blade #1 should be at 10:30. This is one of the most valuable pieces of info I ever learned from this forum.

[Bruce Fenstermacher]

As important as it is to have a Chadwick (or similer system) it is just as important to know how to use it. As a helicopter pilot I've been dealing with these devices and mechanics, some who know how to use them and others who don't, for a long time.

If and that is a big if, the guy who is charging $250 knows how to use the system, the time and money could be well spent over the disappointment and frustratiuon had while someone learns how to use the balancing system with variing degrees of success. There is wizardry and experience involved when operating a Chadwick type system.

My thoughts.

[KG]

I'll mention another tidbit for anyone chasing a prop-related vibration: Double check that your prop is indexed properly to the crankshaft. While facing the front of the engine, with the top dead center mark on the crank flange at 6 o'clock, prop blade #1 should be at 10:30. This is one of the most valuable pieces of info I ever learned from this forum.

Checking this on my airplane is next on my list of things to do. I have a very noticeable vibration between 2000 and 2200 rpm, which is right where I want to put it on my first power reduction for an approach to landing. I've been passing through this rpm range during power reductions to avoid the vibration.

Is a vibration which is more pronounced at certain rpm ranges an indication of improper prop indexing?

Keith

[GAHorn]

I agree with Bruce's comments and will add that an amatuer use of the machines (either Chadwick or ACES) will probably completely MISS the vibration-analysis capabilities those machines can diagnose with regard to cam, indexing, and other vibration sources.

[170C]

I'm sure the vrs comments regarding expertise in using the Chadwick or other equipment is paramount to getting a proper analysis & balanceing job. While I certainly don't have the expertise, I believe several members of the chapter do so. It will be interesting to see how this turns out.

[W.J.Langholz]

I'm sure the vrs comments regarding expertise in using the Chadwick or other equipment is paramount to getting a proper analysis & balanceing job. While I certainly don't have the expertise, I believe several members of the chapter do so. It will be interesting to see how this turns out.

Ole Pokey do you think it will go a little faster after the tune job?


W.

[170C]

No W, I don't think it will go any faster I think my ole pokey is destined to be what it is. I guess I could put a larger engine on and pick up 6-8 mph or maybe put the bigger C-IO360 on (wouldn't mind that) and probably get some additional speed, climb, etc., but at the cost required to do so I would elect to get a C-180. However the budgetary department doesn't permit that unless I am in receipt of a substantial stimulus

[GAHorn]

No W, I don't think it will go any faster I think my ole pokey is destined to be what it is. I guess I could put a larger engine on and pick up 6-8 mph or maybe put the bigger C-IO360 on (wouldn't mind that) and probably get some additional speed, climb, etc., but at the cost required to do so I would elect to get a C-180. However the budgetary department doesn't permit that unless I am in receipt of a substantial stimulus

Hey, FRank! You might re-call we have a certain "associate" over in Looeasyana who might have a "clunker" you could get real cheep for a trade-in if the gov't comes up with a program for airplanes!