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Old May 28, 2012, 03:10 PM
FlipF5D
Joined Nov 2007
146 Posts
Ralf,
I meant not F5D, we're talking about speedcup( yes,I was there) .... I talked with Jan and saw his Viper + your propeller.
He did not have a logger system in his viper but the calculated average consumption was 120 A. ... so IMHO pretty thirsty for the speed....

....and no...I woun´t answer your F5D statment...
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Old May 28, 2012, 03:32 PM
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Mreyello's Avatar
Deutschland, RP, Niederzissen
Joined Dec 2011
849 Posts
Hallo Ralf,
I know about the importance of shaft position and blade-CG for performance and i was about to explain this.
Unfortunately my workshop internet faild ind i am struggling to upload pics and descriptions.

Most of the speedfreaks here in the groups are playing with f5d sized planes at powerrange you call
Quote:
some watts
.
I am happy that you as the designer af the 8,5x23 declare this prop as unefficient in this powerange cause this is what i have preached here a couple of times, but still everybody is keen on these thick bones!
Quote:
remember really good about all these loud laughing f5d pilots some years ago, when they heared about 10x20 or such ideas.
just 7x10 was only a joke for them. you?
4,5 x 4,5 or so - yeah, this have been the really efficient props....
It was Paul and Christoph M and not you which came up with the idea of 11" folders min 6 years ago and they are definitly F5d pilots.
In these years the 7x10 was still competitive in F3S but it never was in F5d, trust me, i tried it,also Jens and a couple of other F5d pilots failed with that prop cause it is not efficient enough with limited energy.You may laugh but the 4,7x4,7 or 5x5 are still good props for F5d and it took years of high level developement to get the big folders on this level.

Quote:
such light and unvisible small models.
Quote:
your "micro" f5d planes with some watts.
Ralf,remember the worldrecord was set by a almost f5d sized plane with only al little more than some watts so maybe it would be more cost-efficient for you to think about new glasses instead of the next 15KW drive!!
Just kidding...

I expect some severely comments now like usual but Ralf,do me a favor, wait until i have finished my build report, you will find enough feed to kick my a$$, i am sure!

Yello
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Last edited by Mreyello; May 28, 2012 at 03:39 PM.
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Old May 28, 2012, 03:35 PM
member of 400km/h club
scorpion-fan's Avatar
Joined Nov 2008
461 Posts
lets come back to the "self made folder topic".
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Old May 28, 2012, 04:00 PM
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Mreyello's Avatar
Deutschland, RP, Niederzissen
Joined Dec 2011
849 Posts
When resin is hard (i took L285 resin with fast hardener and added some heat) you can take out shaft by turning and pulling like steve mentioned.
Remove prop from board
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Old May 28, 2012, 04:26 PM
2012 NZ Speedcup - 231 MPH
DownUnderPilot's Avatar
New Zealand, Tasman, Richmond
Joined Mar 2006
1,942 Posts
Subscribed! Very interesting Mreyello, keep going!!! I want to do the same myself... as much information as possible please :-)
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Old May 28, 2012, 04:50 PM
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Deutschland, RP, Niederzissen
Joined Dec 2011
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Sorry guys,
I would like to continue until i could show a prop-like locking piece of plastic instead of this urgly nugget but i have problems with internet at my workshop-computer where the pictures are saved.

The positive and the first half of the mould is done, it took about 5 hours or so cause i always had to take out gloves for the pictures!

I will continue tomorrow

Yello
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Old May 28, 2012, 05:42 PM
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Darron's Avatar
London
Joined Jul 2003
887 Posts
Quote:
Originally Posted by scorpion-fan View Post
.....and to mill only one small mold for the blade is about 200 euro including the material - p.e. by stefan heuel in germany.
That's very cheap! Can you put me in touch with him?

Great thread Yello!
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Old May 28, 2012, 07:33 PM
2012 NZ Speedcup - 231 MPH
DownUnderPilot's Avatar
New Zealand, Tasman, Richmond
Joined Mar 2006
1,942 Posts
Yello I already have some questions for you

What kind of epoxy did you use? You mention L285 resin. I use West Systems epoxy - can you see an equivalent West Systems epoxy?

With regards to joining the shaft to the blade, how come you don't use something like 12K tow to wrap around the blade and shaft? It looks to me if the bond between the blade and the epoxy is not perfect then the blade will come off under load? What are your thoughts?
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Old May 28, 2012, 09:00 PM
Wake up, feel pulse, be happy!
C₄H₁₀'s Avatar
United States, AK, Fairbanks
Joined Aug 2009
12,372 Posts
This is very, very cool... I don't really have much of a use for it now, but I always enjoy absorbing knowledge like this.

Instead of having to put on gloves for the pics, would it work to put the camera on a tripod and use a wooden stick or something to push the button? Might save you a few seconds
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Old May 28, 2012, 09:14 PM
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Canada, SK, Prince Albert
Joined Jan 2006
1,365 Posts
Great Stuff!

WOW...Great Stuff Mreyello Thanks a heap for posting this up

Is this the special project?

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Old May 28, 2012, 09:55 PM
Registered User
Joensuu, Finland
Joined Mar 2002
1,435 Posts
I'm not Yello, but might be able to provide some answers.
Quote:
Originally Posted by DownUnderPilot View Post
You metion L285 resin. I use West Systems epoxy - can you see an equivalent West Systems epoxy?
L285 is a laminating resin that is widely used in building full-sized sailplanes. Click this for a datasheet.. Nothing special about it, it is just another good quality laminating epoxy that just happens to be readily available on this side of the pond. I'm sure West 105 with 206 hardener would work well.

Quote:
With regards to joining the shaft to the blade, how come you don't use something like 12K tow to wrap around the blade and shaft? It looks to me if the bond between the blade and the epoxy is not perfect then the blade will come off under load? What are your thoughts?
All the pictures shown so far are about making a plug for making the mold. I'm quite sure the actual blade will have tows around the shaft hole and there will be no dry-bonds in it.

Nice thread, btw. I always enjoy seeing how others do stuff, so I can blatantly steal good ideas Thanks for posting!
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Old May 28, 2012, 10:44 PM
2012 NZ Speedcup - 231 MPH
DownUnderPilot's Avatar
New Zealand, Tasman, Richmond
Joined Mar 2006
1,942 Posts
OK, thanks, that helps a lot, apologies for my simple questions!
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Old May 28, 2012, 11:01 PM
Crashing into the sky!
jackosmeister's Avatar
Auckland NZ
Joined Aug 2007
7,179 Posts
Sweet thread, watching with interest
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Old May 28, 2012, 11:33 PM
200mph +
sykotic's Avatar
New Zealand, Manawatu-Wanganui, Palmerston North
Joined Sep 2010
930 Posts
Which of you two ^^^ are going to sell me a nz made prop


Looking forward to the next pictures!
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Old May 28, 2012, 11:39 PM
2012 NZ Speedcup - 231 MPH
DownUnderPilot's Avatar
New Zealand, Tasman, Richmond
Joined Mar 2006
1,942 Posts
If you want a 7x11+ then that's what I'll be attempting .... baby steps though....
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