Jabiru Composit Prop

[jetjr]

Its not just the prop material

 

For example a wooden prop that is often out of balance, has non matching pitch and needs tracking every service, Ive had them 10-15mm out. Also changes with weather.

 

OR a well balanced composite that runs smoothly all the time, Id say the composite would be softer on the crank.

 

Im a big supporter of dynamic balancing too.

 

They have sold plenty. Very few others have been successful with CF props on 2200 however. Bolly have plenty with same blades and smaller hub running on 3300's for a long time.

 

The concerns re these issues is maybe why the Jabiru hub would look at home on a 300hp installation

 

 

[Bruce Tuncks]

Some time has passed now, so how are those composite props going?

 

My original wooden prop is looking a bit shabby these days, so I am seriously interested.

 

Do they have any mechanism to be "softer" on the crankshaft than the early ones which failed? Or were the failures confined to the props themselves and no harm came to the engines?

 

 

[Keenaviator]

Mines been on about 3 years and it's going really well. Jabiru did a fair bit of development work on this prop and tried carbon but found it to be too stiff and caused resonance/vibration problems. The fibre used in their composite prop is I believe pretty standard glass fibre which has a bit more give. That said I had a Patroney composite prop on my Jabiru powered Corby Starlet and had no problems with that - and still no issues with it's new owner at West Sale. Laurie

 

 

[scre80]

Some time has passed now, so how are those composite props going?My original wooden prop is looking a bit shabby these days, so I am seriously interested.

Do they have any mechanism to be "softer" on the crankshaft than the early ones which failed? Or were the failures confined to the props themselves and no harm came to the engines?

Hi Bruce,

we have 2 J 170 aircraft with them at the gawler airfield, no issues at all. Have a look yourself, 7385 & 8538

 

 

[Jabiru Phil]

Hi Bruce,

 

Best thing I ever did. I was a tad surprised that Jab suggested a finer pitch to the wooden prop when I purchased.

 

It outperforms the original in climb,cruise,smoothness and noise which surprised me. Performs as stated.

 

Three years now and very pleased.

 

Fairly expensive, so wouldn’t be changing over unless the old prop needs replacing or you want the above benefits.

 

Cheers.

 

 

[ryan4321]

Got the recommended Composite prop Jabiru promote / recommend on their site. It made me reaslise how far out of balance my wooden prop was previously. The dash no longer vibrated like a 60's washing machine. Much better for the engine I'm sure. A must do IMO.

 

Just some additional info to expect... Leading edge fades from black to a cream and there was small bubbles / pits in the leading edge from manufacture.

 

I think the problem with the wood props is moisture. They are much more prone to imbalances.

 

 

[cooperplace]

Jetjr - I'm aware of all above and how Steve nearly lost the front of his plane testing the Bolly on the 2.2 engine.

is there a thread on this? sounds very scary

 

 

[Peter Anson]

I think that the props Bolly make for Jabiru are glass fibre while the ones that Bolly sell are carbon fibre so much stiffer. Jabiru obviously thing the more flexible blade is better for their engines.

 

is there a thread on this? sounds very scary

This was the early Bolly "Duralite" composite hub prop which shed blades on the 2200. My own experience using a Duralite on a 3300 was not as instantly dangerous but also unhappy. My 2 blade prop cost $1900 over 6 years ago. Looked schmick, worked well but the bolts needed retorquing every 25 hours (well less than that really) and when I did my 100 hourly I found that the blades were mis-tracking by 6 mm. I sent it back to Bolly who said there was nothing wrong with it. I made a tapered shim to correct the problem but 15 hours later the tracking was out again. What was happening was that the composite hub was creeping, gradually changing shape. Yes, it was always torqued carefully to Bolly's recommended specification. I could actually measure the distortion. It's definitely worth waiting a few years for somebody else to test a manufacturer's new products. For the past 4 years I have been using a wooden prop with no problems.

 

 

[jetjr]

I think theres old Bolly props and the new ones, different people running the show.

 

There is a long history of problems with composite props on 2200, Jab latest is glass and seems to work well

 

Plenty of 3300 with carbon types out there with few problems Ive heard of other than the one that Jab says was onstalled incorrecly

 

 

[Peter Anson]

Hmm. I bought my prop from the new crowd who were struggling with problems left to them when they bought the business. Not much help to me though. I still ended up with $1900 worth of rubbish. Incidentally I am reasonably experienced: built my aircraft from scratch, have rebuilt and upgraded my engine and have even reshaped a prop that was not correctly pitched by a US manufacturer. Been happily flying behind my modified prop for 150 hours now. If after all that I can't fit a composite prop it must be an arcane skill indeed.

 

 

[derekliston]

I have the Jabiru composite prop on the 2200 on my CH701. It was pitched by Jabiru to suit the airframe, don’t ask me what they pitched it at! Don’t have a lot of hours on it yet but it is smooth as silk and if I go full rpm with the brakes on and then roll, I am off the ground in 3 seconds. I don’t think (I stand to be corrected!) the 100hp Rotax gets off much quicker. So far I am very happy with it.