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13brv3 wrote:Thanks for the link. I don't see how that prop isn't stalled at lower speeds.
Rusty

Maybe they are DE-Tuning the 912 performance to make the Aerovees look good? XD

xeriotti wrote:Maybe they are DE-Tuning the 912 performance to make the Aerovees look good? XD

This is the first factory Rotax that Sonex has built (with help from a hundred people <g>). Have they even flown it yet? It will be really interesting to see what they record for performance. I will predict that exhaust wrap won't be on there long. I bet I had exactly the same wrap, on the same exhaust, and it went less than 15 hrs.

Rusty

xeriotti wrote:

garyb wrote:Hi
My Rotax powered Sonex has a 68 inch wooden GT propeller off a Tecnam P2008 .Static rpm is around 5100, Solo it climbs sea level at 1800 fpm at 70 kts, cruise 2500' 120 kts 5200 rpm and 5500 135 kts WOT it pulls to the red line 5800 rpm. The prop could probably do with a little more pitch.
Cheers

Gary!! Thats great info!!! Are you aware of the pitch of that propeller? If its not explicit in the model... Maybe we can decode it from your serial number. The other way is to measure the angle at 75% of the radius. But its a tricky task (much more tricky if installed on the plane!)

How fast is your level flight at 5800 WOT? And what fuel consumption are you seeign at your 120kt 5200rpm cruise?

PS: Those numbers are amazing... I think i went the right way with the 912...

Hi
I worked out the pitch to be 67.5 inches the P/N of the prop is (GT2-173-VRR-FW 101 SRTC) so I think GT don't want anyone to know the actual pitch. At WOT I cant leave it there as that's were the redline starts, its burning 4 gallons/hour in cruise.
Cheers

garyb wrote:Hi
I worked out the pitch to be 67.5 inches the P/N of the prop is (GT2-173-VRR-FW 101 SRTC) so I think GT don't want anyone to know the actual pitch. At WOT I cant leave it there as that's were the redline starts, its burning 4 gallons/hour in cruise.
Cheers

I ve been loking at that propeller code before, as its visible in one of the pictures of your plane... I unseccesfully tried to decode it...

-GT2 beign the brand and type maybe
-173 is diameter in centimeters
-VRR-FW maybe having something to do with pitch <----------- Any ideas???
-101 is the bolt pattern for sure, 101,6 thats 4"inches

Tried thing like this but it may be more intrincate



V + R + R = 22+18+18 = 62

FW possibly means sepparately 6 and 23 62,3?

Yes, i was really trying to find out what propeller was that XD

I am installing an AEROMOMENTUM AM15 in my OneX and have decided on a 4 blade 58” Bolly prop. I know it’s not optimum length but ground clearance is an issue. Does anyone know if, and where, a person could get extended gear legs manufactured? I think 4-5 inches would be answer. I’ve already installed 5:00x5 tires.

Hi "Onex0029??",

Onex0029 wrote:Does anyone know if, and where, a person could get extended gear legs manufactured?

https://sonexbuilders.net/viewtopic.php?f=5&t=5456&hilit=bennett#p41272

Hint: Read forward from the linked post.

Good Luck,

Wes

I fly a fp 2-blade Sensenich wooden prop on my Rotax/Legacy combo. The prop has the common conical Sonex hub intended for the scull cap spinner and came beautifully statically balanced from the manufacturer- I get 5200 rpm wot gnd sl and a shade under 5800 rpm flat out at 3500´amsl: rejoice!!

But Rotax insists you also need to dynamically balance the prop- easier said than done with the conical Sonex prop hub and the skull cap spinner: where to position the neccessary balancing weights?

I can think of only one place- the prop hub. Having said that, the balancing machine comes up with some hefty weight values, I am guessing because of the very small radius (half the prop bolt circle diameter) on which they must function. I am sure this is fine if you want your hub to look like a swiss cheese, but structural integrity has started to worry me.

Comments?

Kai wrote:But Rotax insists you also need to dynamically balance the prop- easier said than done with the conical Sonex prop hub and the skull cap spinner: where to position the neccessary balancing weights?
Comments?

Ideal time to ditch that overly heavy (3lbs) lump of aluminium with real a spinner.

I balanced my 3300 jabiru sonex and yes the heavy spinner is a pain. I have a couple of extended prop bolts that have as many as 10 washers to balance. Felt better about that than drilling out weight. My a&p asked about it the next condition but said it was fine. I did notice a difference in vibration

tx_swordguy wrote:I balanced my 3300 jabiru sonex and yes the heavy spinner is a pain. I have a couple of extended prop bolts that have as many as 10 washers to balance. Felt better about that than drilling out weight. My a&p asked about it the next condition but said it was fine. I did notice a difference in vibration

Did you do a static balance before installing & doing the dynamic??