Prop Balancers

[Brett]

Just curious,

 

Are there any other affordable prop balancers out there for the humble homebuilder apart from the dynavibe and PL-4 from Smart Avionics?

 

It will probably only be used by a few of us in our general area.

 

I know of a few others that are significantly higher in price but does anyone also that has much to do with them recommend one over the other?

 

Btw no one close to us has one and no business's withing 450km has one either...I guess could travel to one of the options but will it be done right the first time? I'm chasing an on going issue and keen to have a good go at this balancing option.

 

Thanks......

 

 

[Kyle Communications]

Just make a small bearing hub up and statically balance your prop then throw a balancemaster ring on it. Should solve your issue well enough

 

 

[Old Koreelah]

Achieving static balance is not rocket science. There are probably several resources you can google.

 

I bought some al. angle from Bunnings Aerospace and set up a static balancer in my shed out of the wind.

 

A pair of tracks mounted exactly level, with enough space between for the prop to spin. Insert a tight-fitting axle and let it roll back and forth on these tracks. Go and do another job for an hour or two until it stops. Repeat several times to establish the heavy section. Apply a touch of clear paint to the lighter end until it never stops at the same spot.

 

 

[ieadave]

I have my A&P balance my prop anytime work takes place and the prop comes off. Anyone flying behind a jab should fly with the prop balanced while on the plane. Smooth! The results will let you sleep better at night. Spend the money and use a pro. Dave

 

 

[flyerme]

Heres how i do it

 

 

 

[Brett]

I have admittedly not static balanced it yet. Probably worth a shot first... Can't hurt thats for sure... it's a Sensenich prop so assume they balanced it correctly before they sent it.

 

 

[Kyle Communications]

Not necessarily. Each blade most likely will not be the same weight. Gramms make a big difference. You need to static balance it first. That is where you can start from.

 

 

[ieadave]

My A&P has felt for years that balancing the prop digitally on the plane was a major help protecting Jabiru engines from sheared flywheel bolts. Jabiru did finally issue the SB for the lock washers but I still think a proper prop balance is a major " must do" for flying over scary landscape. I've done a balance twice over 8 years when the engine had internal work done. I've Just finished a major repair on a second Jabiru powered plane with broken flywheel bolts and the last work before test flight will be a prop balance before it flys again. Just my opinion. Dave

 

 

[Brett]

I'm definitely keen to do a balance hence why I was hoping someone may have come accross a balancer perhaps more affordable than the ones I listed... $1800 for the Smart avionics one is the cheapest one I've found... plus add on the import duties lets call it $2k ....

 

 

[facthunter]

Don't buy your own. You wouldn't use it often enough. Static can't do any damage but anything with length like the crankshaft must be dynamically balanced. Balancing components separately must be preferable as a principle, to using the prop to balance the engine. It's torsional harmonics that affect flywheel bolts on a jab (and maybe the starter action).. Best to use a wooden prop (or light equivalent). Nev

 

 

[skippydiesel]

I have admittedly not static balanced it yet. Probably worth a shot first... Can't hurt thats for sure... it's a Sensenich prop so assume they balanced it correctly before they sent it.

Assume no such thing !

 

Stage 1. Be obsessive about your static balance - get help if you dont understand how to do it. This will prepare your prop for Stage 2.

 

Stage 2. Obtain the services of a person who knows how to use their good quality dynamic balancer (I used SuperAir, Armidale, NSW)

 

 

[Old Koreelah]

...It's torsional harmonics that affect flywheel bolts on a jab (and maybe the starter action)...

I had my flywheel bolts checked about 120 hrs ago, but I have a nigling concern about my new LiFePO4 battery.

When the engine's warm, starting is instant; I wonder if it's putting too much load on those tiny little bolts.

 

 

[facthunter]

The shock load of the drive engaging is a worry. If you could have it just behind the propeller It would be a lot better. That was a proposed mod for the non Rod Stiff engine. Long shaft from the starter motor with no change to the position of it. Nev

 

 

[Old Koreelah]

In a previous discussion of this issue a possible solution was floated: some sort of “dampening” of the initial cranking shock- either mechanical or electronic.

 

 

[facthunter]

The "early" Continentals had a pull out knob and cable that engaged the drive before the motor cranked at all. Like the immediate post war Peugeot cars. Chev cars had a pedal on the floor that did the same thing. The spragging clutch on the Rotax has been known to give trouble also. The "usual" ring gear on the flywheels of many cars gets to be a bit ordinary with the starter gear slamming into it after a while . It's a pretty savage concept. If it ever jambs in, the starter centrifuges to pieces pretty fast. If the drive goes through an accessory drive case the internals should be protected by a "quill" drive designed to fail first . It's a problem area. Engine kick backs when the engine is too hot are damaging also. It's a fact the jabiru flywheel coupling is "marginal" needing extra care and monitoring. . Nev

 

 

[Old Koreelah]

I agree Nev; it's always amazed me how the mechanism can survive many thousands of those violent starting procedures. Hand starting would be kinder to those little flywheel bolts, but (even though it would be easy to modify my Jap's cold start kit to allow hand cranking) I don't plan on doing it.

 

 

[Jaba-who]

Getting back to the original question about dynamic balancer.

 

I'm also in the market for one ( we have about 10 Jabirus in the local area so I reckon we could use one among the group. )

 

I'm going to Oshkosh next week and going to buy one. Not sure which model or brand - last time I was there 2014 there were about 3 or 4 manufacturers had models for sale with airshow specials but I didn't think I had the need to justify the cost but now we have a veritable jab colony it's a different story. so I'm hoping for the same or other manufacturers being there again.

 

 

[Brett]

My friends are also going over to Oshkosh this year... could you keep me posted please Jaba-who on what you come up with and thoughts about whats on offer?

 

 

[Jaba-who]

My friends are also going over to Oshkosh this year... could you keep me posted please Jaba-who on what you come up with and thoughts about whats on offer?

Sure thing.

 

 

[Kyle Communications]

I have to say the Dynavibe is a piece of cake to use. very easy and simple to install and use. I bought mine secondhand here. It was actually advertised on this forum. Think I paid 1200 AUS for it so it was a steal. if you tried to get one in now I think around 3K with exchange rate plus freight then GST

 

 

[Kyle Communications]

Just did this last week . test of before and after for a Balancemaster ring

 

 

 

[Jaba-who]

Ok. Been looking on the internet and found quite s lot about dynavibes. Seems people are pretty happy with them.

 

The basic model seems to be about US$1500 from several sources ( including aircraft spruce who will have it at Oshkosh for me to pick up if I buy from them.

 

I’ve had a look at the PB-4 Smartavionics website but have to say after buying or using a number of devices that link to computers and iPads etc I have been singularly unimpressed. ECGs, ultrasound probes, various microscopes and boroscopes. They all seem to be buggy and often don’t really work. So I’m loathe to get sucked in to another one.

 

 

[xair1159]

I have owned and used both the Smart Avionics PB1 and currently the PB3, and was very pleased with both of them.

 

The PB3 works perfectly with no problems linking to it via bluetooth and gives good results.

 

I have also borrowed and used the Dynavibe - works fine but not as versatile as the Smart Avionics.

 

Nick

 

 

[1Phils]

I'm definitely keen to do a balance hence why I was hoping someone may have come accross a balancer perhaps more affordable than the ones I listed... $1800 for the Smart avionics one is the cheapest one I've found... plus add on the import duties lets call it $2k ....

Yes but they only balance at set revs so balance for cruise or full throttle and either will not be in balance at either revs.

 

 

[Brett]

My issue is at roughly 50% power at about 2200 rpm mostly... it would have to help..