BCP community,

I am considering purchasing a propeller balancer for my personal use. Does anyone have a recommendation on make and model for a decent system that won’t break the bank?

Thanks for any input.

You could pay someone to balance props for you a number of times for the price of a good machine. I’m sure you realize that.

But, the question in my mind is, what will you do with the data you derive from CHECKING the balance of your prop? If you then add balance weights to a prop, are you not performing “maintenance”, which requires a logbook entry signed by a mechanic?

I don’t know the answer to that question....but it’s one I’d want the answer to.

I’d also want to make darn sure I got some REALLY good training on how to use the thing.

I’ve watched a mechanic who really knew what he was doing fiddle with prop balance on one plane, and couldn’t get things to come together. Gave up.

FWIW

MTV

I used to balance propellers with a Helmuth Chadwick unit which worked really well but I believe that unit is crazy expensive.

Even with my A&P I’m only a so-so mechanic but I found it very easy to use. It is extremely tedious work as it takes a bunch of preparation and repetition but it’s not difficult.

Dynavibe seems like a good way to go but that’s just speculation as I’ve never actually used it. I’ve had a couple long conversations with the dynavibe sales rep and saw a demo, it looks very user friendly.

You could get 4 or 5 prop balances done for the price of a dynavibe but where’s the fun in that?

I just spoke with my dad about this.

Our little consortium (OK really little...2 airplanes) owns a PB3 balancer. It's hard to use but does work. Directions are written for those who are technically very saavy which makes it difficult for us hard heads. Viking Aircraft Engines will rent you a Dynavibe for $130 a week. It's a much more refined process as I understand it.

I don't think you asked about the legality of it. For what it's worth we use ours on our E-AB aircraft. No idea what paperwork is involved with real airplanes.

Oh yeah, forgot to add that we were already in the green zone without adding any weight and we still have a rough spot at the mid 3000 rpm range. Money well spent. [emoji15]

gbflyer wrote:I just spoke with my dad about this.

Our little consortium (OK really little...2 airplanes) owns a PB3 balancer. It's hard to use but does work. Directions are written for those who are technically very saavy which makes it difficult for us hard heads. Viking Aircraft Engines will rent you a Dynavibe for $130 a week. It's a much more refined process as I understand it.

I don't think you asked about the legality of it. For what it's worth we use ours on our E-AB aircraft. No idea what paperwork is involved with real airplanes.

Oh yeah, forgot to add that we were already in the green zone without adding any weight and we still have a rough spot at the mid 3000 rpm range. Money well spent. [emoji15]

Drift Alert!

3000 rpm, this is a geared engine? I would be more suspicious of an engine problem, ignition or reciprocating mass. Prop balances typically are done for just one rpm (cruise) and don’t really fix rough spots in my experience.

YMMV

Halestorm wrote:

gbflyer wrote:I just spoke with my dad about this.

Our little consortium (OK really little...2 airplanes) owns a PB3 balancer. It's hard to use but does work. Directions are written for those who are technically very saavy which makes it difficult for us hard heads. Viking Aircraft Engines will rent you a Dynavibe for $130 a week. It's a much more refined process as I understand it.

I don't think you asked about the legality of it. For what it's worth we use ours on our E-AB aircraft. No idea what paperwork is involved with real airplanes.

Oh yeah, forgot to add that we were already in the green zone without adding any weight and we still have a rough spot at the mid 3000 rpm range. Money well spent. [emoji15]

Drift Alert!

3000 rpm, this is a geared engine? I would be more suspicious of an engine problem, ignition or reciprocating mass. Prop balances typically are done for just one rpm (cruise) and don’t really fix rough spots in my experience.

YMMV

Hahaha!


Yep, geared. We are thinking gearbox, the more we learn. The engine guru said to increase prop pitch, we might be on the fine side. It runs smooth at cruise. The other engine is smooth at all settings, but has stock jugs.

Sorry about that Squash.

Ive been told tbat a dynamic prop balance is not forever.
Wear n tear ln the engine & tbe prop itself, even just the normal laint erosion, can ter the bslance enough to be detectable- at least with the balancing gizmo. I had my freshly OH'd seaplane prop dynamically balanced a couple years ago- I didnt notice much difference, bjt the gjzmo did.

mtv wrote:You could pay someone to balance props for you a number of times for the price of a good machine. I’m sure you realize that.

But, the question in my mind is, what will you do with the data you derive from CHECKING the balance of your prop? If you then add balance weights to a prop, are you not performing “maintenance”, which requires a logbook entry signed by a mechanic?

I don’t know the answer to that question....but it’s one I’d want the answer to.

I’d also want to make darn sure I got some REALLY good training on how to use the thing.

I’ve watched a mechanic who really knew what he was doing fiddle with prop balance on one plane, and couldn’t get things to come together. Gave up.

FWIW

MTV

Nothing gets done on my planes without a mechanic. Those of you who know my planes know that my mechanic has a key to my hangar and takes care of both planes. I don't swap skis, rotate tires, or basically do anything without my mechanic. Well, I will remove the cowling and change oil, but that's about it. Frankly, I just don't have the time to mess with the planes. It's much easier for me to pay him to do it while I'm at work. Which is why this prop balancer topic has come up.

My MT prop on the husky was spitting grease. It was time for an overhaul anyway and I wanted to upgrade to Nickel leading edges. So off came the dynamically balanced prop (balance job #1). Prop goes to Germany and comes back. Reinstalled on plane. Since my mechanic doesn't have a prop balancer I need to take it to someone else. Phone calls. Everyone busy when I'm not. MARC maintenance on the airfield says drop the plane off and they will get to it when the winds are good. Out of the protected hangar goes my plane. Plane sits around for a couple of days until they have time to get to it, and of course, when I'm at work. So it gets done finally (balance job #2). Fly the plane and it starts spitting more grease. MT says send the prop back for warranty work because the seals they used were defective. Off comes prop. So now I'm faced with getting another balance job. If I purchased my own balancer, my mechanic could use it and I am much more able to coordinate my time to help him than other shops. Plus, I have the wagon that will need a balance job soon as well.

So this is mostly a convenience thing for me. My mechanic would be doing the work if he is willing to operate the equipment. Otherwise, it's back to MARC I go. Not a huge thing, but I hate dropping off my plane and keys to someone who isn't familiar with my stuff.

Checked their website, prices for a Dynavibe set-up range from $1500 to $4K.
Might be worth it just for convenience sake, plus you can have your guy re-balance your props on a regular basis.
Plus maybe let him use it to do other balances, for a fee.
A buddy of mine got his IA a few years ago, he does his own annuals as well as for just a couple very close friends.
But he does do a lot of prop balances with his Dynavibe.
Forget what he charges, it took him a while to oay it off but now the fees go right into his pocket.
Plus he enjoys doing it.

I've used a Chadwick quite a bit, a Dynavibe once, and more recently an ACES machine a fair amount. Unless you're moving into heli's anytime soon I'd skip the cost and complexity of the Chadwick and get an ACES. I see them on Ebay once in a while and IMHO if you own more than one airplane, or have a few buddies with airplanes, it's a reasonable tool to own for the reasons you are experiencing. If you can change oil, and read & comprehend reasonably well, you should be able to balance a prop, they are dead simple. Understanding all the things that can affect prop balance is another thing, but even the average AP/IA doesn't understand all of those issues.

My experience has been that a mechanic that has to rent or borrow a prop balancer is not going to spend as much time tinkering with the tool as he/you would if he owned it.

It's also worth noting, since the question has already been brought up about legalities, that these tools require calibration / certification.

Take care, Rob

I picked up the ACES that was on sale here a while ago. Haven't had time to use it yet though. At school we used learned on Chadwicks, a 177 and vibrex 2000. The 177 is old and more complicated, and requires a strobe for RPM. The vibrex 2000 is pretty easy, but fairly expensive as well. My instructor said the ACES units he used weren't his favorite for helicopters, but for occasional use he said you can't beat the price. FWIW.

To follow up with the OP, we rented the Dynavibe from Viking. It's way more user friendly and repeatable than our PB3, in fact it is getting returned.

I am really glad that you guys take dynamic balancing seriously. I bought myself an Aces unit about a year or so ago and it works great. To get the full potential horse ponies out your engine you have to balance. But the guys at my airport here in Texas think it's a bunch of nonsense! All their plane are running smoothly without it. Never needed in the past, so why do it. If I start talking about harmonics they just roll their eyes.

Many schools of though on dynamic balancing. It is not something you want to do to a relatively new or freshly overhauled prop. They kind of need to break in a bit (they do actually balance it at the OH shop). The bearing races get set, grease repositions itself and so on. I tend to do it around 100 hours, it has never been dramatic. I always do it on the turbines, a lot more mass swinging out there. There is a bit of harmonic witchcraft going on with some turbines. There is a stack interaction with the prop that shows up at a couple of different multiples of prop and engine RPM. I learned from some Pratt engineers the there are certain prop/engine combos that tend to self destruct from this harmonic effect. There where a couple of french engines that had this issue. I always was a bit weary on Hartzell greased props and balance, you would seem to be affecting the balance a tiny bit by not pumping in exactly the same amount for each blade.

I always let somebody with some experience do it. I owned a super cool Chadwick that printed out the cards, had the strobe for rotors, several different accelerometers. It was also in the 20K price range. I let the mech that knew it use it. You could check vibration on the front and rear of the engine at the same time. We mainly had it for the MORE program to extend engine life. My prop shop will balance your prop if you drop by his shop, $100.

So all said, my present aircraft, the 206 runs very smoothly, fresh overhaul, 200 TTSN prop. I don't think I will mess with it for a while. Yes you are supposed to make a logbook entry. This kind of lets somebody downstream know why there are some extra screws and washers on the backplate. Don't forget to mark your spinner to keep it indexed if you do balance the prop.

I went down the MT maintenance rabbit hole and had a similar experience pulling prop for repair, rebalancing, pulling it off again, etc. The cost and time to fly to another airport and pay for someone else to do the balancing each time added up fast. Ended up investing in a DynaVibe which has been great. I balance once a year because it always has measurably changed by then.

Different people have different comfort levels wrenching on their airplanes, but the DynaVibe isn’t crazy expensive and it’s relatively straightforward to use. At a puttering around sort of pace I usually get mine done in an hour or two. Balancing makes such a difference for smoothness and comfort, especially on longer legs.

Thanks all for good info on the topic.

Kiteguy!!! Welcome!!!!!!!!

Kiteguy wrote:.... I balance once a year because it always has measurably changed by then. ....

I think a lof of people think a dynamic prop balance is a one time thing.
As moving parts wear, it stands to reason that they change as does the balance between them.
Interesting that it is noticeable after as little time as a year.

So, since I was talking to my PT6 rep Kevin, who does prop balancing on the side, for his thoughts. He uses the Microvibe and swears by it, he has an ACES and it is permanently shelved.

He has some interesting comments on certain props, from the balance perspective. He hates to do McCauleys, the props have blade track problems out of the box. It shows up as a balance issue, but it just one blade making more or less thrust than the others. So being the curious Thomas I asked about the effect of greasing and balance on Hartzell props. He recommends waiting at least 100 hours for the first balance. Do the proscribed greasing 3-6 pumps per blade (depends on your model). Run the prop to full power and back several times while cycling the prop through its pitch range. This allows the grease to find its special place in the hub. Now he likes Lycomings better than Continentals, for balancing, as there are 20 balance holes on the flywheel to place weights, vice the backing plate. He says you can do it every 100 hours (the prop greasing schedule) but the grease does not hugely affect the balance, being fairly close to center mass. What does effect balance is abrasion, abrasion boots or de-ice boots. Wear on these defiantly affect balance. So bottom line, depends on how you use your aircraft. If your beating the prop up with dirt and gravel, then very 100 hours or annual. If you are a bit nicer to your propeller, then you don't need to until it feels like it needs it. You need something like .3 to actually feel it which is about double out of limit. There is a link here so you can get the Chadwick Smooth Prop balancing guide, it is an FAA approved document.

If you feel prop imbalance frequently, then you may have something else going on, this crank balance weights, or you are a bit hard on your prop.

Look for the Smooth Prop Guide on the list of downloadables
https://www.expaircraft.com/PDFgallery.htm