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graupner prop

Old 02-11-2005, 07:34 PM
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desertbuzz
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Default graupner prop

found a graupner prop in my tool box.
It's about 6.9 cm (2.71 inch) in diameter.
On the back of a blade it has a marking saying X 70

what does that mean? Is it a reference to pitch?
Old 02-12-2005, 12:02 AM
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Ron Olson
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Default RE: graupner prop

I would guess that they rounded off the 6.9 cm (or 69 mm) to 70. Most of the Graupner and other props use Octura's pitch of 1.4 times the diameter.
Old 02-12-2005, 04:37 AM
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Default RE: graupner prop

good to know.... I thought they used a pitch 1.2 X diameter.

And how would that perform on a 48" inch boat / suberged drive / .91 engine ?
Old 02-12-2005, 09:06 AM
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Default RE: graupner prop

It might be able to turn it.
Old 02-13-2005, 03:43 PM
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pompebled
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Default RE: graupner prop

Hi Buzz,

I'm starting with the Graupner 70mm hydroprop on my surface driven Screwdriver, so an 70 X might work submerged, I'd start with a 65X if you can get your hands on one.

Regards, Jan.
Old 02-14-2005, 12:03 AM
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Default RE: graupner prop

Thanks Jan for the info,

By the way ...I received mail from Alan Baldry... he said the following:

"My son, Philip, runs two Screwdrivers, one with a Picco 67 and one with a Webra 91, both perform very well although the high torque and low revs of the Webra do give rise to some handling problems. first Screwdriver was set up with a solid shaft in the conventional position out the bottom of the boat but the handling was appalling. The boat was very unstable and would 'roll over' in turns. I then tried a flexi-shaft through the lowest point of the transom, virtually straight out of the back of the boat with an out-drive leg, but really struggled to get it to perform. The boat bounced around and was not particularly fast.
The next set-up was to bring a flexi-shaft through the bottom of the boat, then parallel to an out-drive leg about 15mm below the line of the hull. This gave a dramatic increase in speed but the boat would bounce through the corners and perform some alarming roll-outs - always when you least expected it!
The final and most successful set-up is similar to the above but with the shaft only 3mm below the hull
."


He promised to send me pics detailing the setups.
I'll keep you posted.
Old 02-14-2005, 12:53 PM
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pompebled
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Default RE: graupner prop

Told you, Alan is a nice guy!

Please mail the pics of his set-up.

Regards, Jan.
Old 02-28-2005, 03:12 AM
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Default RE: graupner prop

Dear the Friends,
I want to you to show New Propellers!
It is modification K-Serie! (63 mm)
The left-hand and dextral rotation....



Thanks!
Alex.
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Old 02-28-2005, 03:15 AM
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Default RE: graupner prop

I have forgotten to you to notify,
Graupner does(makes) these propellers of plastic - (Carbon)...
And I put aside money from a stainless steel!!!


Thanks!
Alex.

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