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Old Jan 24, 2012, 04:51 PM
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Graupner Elektro Prop Pairs

I purchased several Graupner Electro Propeller Pairs recently for my X8 configuration with the Hoverfly Pro board. One Trackor and One pusher is what it says in the description.

I thought originally, one for the top and one for the bottom. Then I've been reading here regarding the various clockwise and counter clockwise configurations. Knowing the both .. Totally threw me for a loop.

How do I know which propeller to mount where? as both are obviously different.

I can't seem to find any documentation regarding pairs?

One prop has an L on it, the other doesn't.
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Last edited by Razzil; Jan 24, 2012 at 05:04 PM. Reason: spelling mistakes
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Old Jan 24, 2012, 05:14 PM
Air Traffic Controller
United States, TN, Knoxville
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As the props spin, you should be able to imagine which way it would push the air. This, of course, should be down. Take one, rotate it clockwise. If the curve of the prop blades looks as if it would push air down, then that's your clockwise blade. The other should push air down counter-clockwise.
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Old Jan 24, 2012, 05:51 PM
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Also, imagine the prop climbing as it turns. The second number is the size of the prop tells how many inches the prop will climb in one rotation. The leading edge in the rotation will also be the rounded edge as opposed to the sharp edge of the trailing edge. You are trying to figure out which way the prop is designed to turn right?
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Old Jan 24, 2012, 05:57 PM
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Which propeller to use where .. both are slanted differently.

Should I put one set away and use just the same?

Why pairs?
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Old Jan 24, 2012, 06:05 PM
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Does the one without the L mean clockwise

and the one with the L mean counter-clockwise
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Old Jan 24, 2012, 06:31 PM
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http://site.nitroplanes.com/prop7.jpg

This prop is a counter clockwise prop. Your octo must have 4 CW, and 4 CCW props on alternate arms normally. If all props spun in the same direction, your craft would rotate in the opposite direction, which is undesirable. Alternating the props allow a yaw-stable copter. Look at your props and compare them closely to the picture. I don't know if the L means CCW or CW as I'm not familiar with those props.

In the case of a quad-8, the top props turn one way and the bottoms turn the other normally. Of course there could be variants, but in nearly all cases, half the props you use have to spin on one direction and half in the other.

After a little searching, the Graupner prop with the L is the pusher and in their case, the Clockwise prop. The other is also known as a tractor (because it pulls things) and is the Counter Clockwise prop.
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Last edited by Webheadfred; Jan 24, 2012 at 06:40 PM. Reason: Added Graupner
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Old Jan 24, 2012, 06:37 PM
Pants first, then shoes
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On the X8 start by following the HF diagram in the manual which has all top props spinning clockwise and all bottom props spinning counter clockwise. Do this rather than the alternating method till you become familiar with how the props work with different configurations etc.
Also make a note of which way up your bottom props face. The top side of the bottom props should still face upwards the same as the top props face.

I would also suggest you take a photo of the X8 with the props on for us to see first before you try to fly. It sounds like you are unsure so best to check first.
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Old Jan 24, 2012, 06:52 PM
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Thanks for all your help. The sharp edge is the edge that spins into the wind.

That being the case the prop marked with L means counter clock-wise.
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Old Jan 24, 2012, 06:54 PM
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No. The sharp edge should be the trailing edge! The rounder edge should be into the wind.
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Old Jan 24, 2012, 06:55 PM
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The edge which is higher spins into the wind. Can you post a photo of the two different props so we can correctly identify them for you.
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Old Jan 24, 2012, 07:21 PM
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I have uploaded two photos. One from Droidworx and the other from my CX-4 in an X setup. I don't have the other 4 motors mounted yet.

Picture One (Mine)
Picture Two (Droidworx)
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Old Jan 24, 2012, 07:48 PM
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Ok from your picture, your props are on incorrectly. I'm assuming that the red tape is on the front of the copter.

In that case.....

For a quad: the props with the L on them should be on the Front Right and the Back Left. The props without the L should be on the Front Left and the Back Right.


For an X-8: The props with the L should be on the top... Without the L on the bottom.

All this assumes that you're using the HoverFly Pro. Of course, another controller could use a different configuration.
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Last edited by Webheadfred; Jan 24, 2012 at 07:56 PM. Reason: Clarification
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Old Jan 24, 2012, 08:20 PM
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ok, now it makes sense. Clear as mud.

It does though ... the rounded lip is pushing the air down making it hover.
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Old Jan 25, 2012, 06:58 AM
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Columbus, IN
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Quote:
Originally Posted by Razzil View Post
ok, now it makes sense. Clear as mud.

It does though ... the rounded lip is pushing the air down making it hover.
Let us know how well the Graupners fly. Are they stable and efficient? Most of the folks here, including me, fly with the APC slow-fly and thin electric brand of props.
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Old Jan 25, 2012, 09:26 AM
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USA, FL, Winter Springs
Joined Apr 2006
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Glad to hear you're making progress.
Reference the quickstart guide for propeller direction

http://www.hoverflytech.com/uploads/...tGuideV2_1.pdf


Quote:
Originally Posted by Razzil View Post
ok, now it makes sense. Clear as mud.

It does though ... the rounded lip is pushing the air down making it hover.
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