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Old Mar 17, 2012, 04:12 PM
I don't like your altitude
Stupot46's Avatar
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I was looking at Eagle tree systems.Not cheap at about $250,but must be worth it for fliers with expensive planes.
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Old Mar 27, 2012, 06:28 AM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
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I would like If possible to use torsion rods on my HoVII.As I said elsewhere I have in the past used the h/t aluminium from knitting needles with good results.In Herks Nurf he mentioned using carbon.My questions are-
Rod or tube.I have some 4mm o/d 2mm I/d to hand.
The fittings to use.Is it possible to get a good enough fixing internally ie a wire crank fixed in the rod,or an externally fixed arm.
Any advice will be greatly appreciated
Regards Stuart
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Old Mar 27, 2012, 08:06 AM
Herk
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Virginia USA
Joined Jun 2007
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Stuart, I don't remember how much power or speed you expect of your model, but I think that 4mm CF tube should work for you.

It depends on so many factors - how long is the rod going to be when it is installed? How big are the flight loads on the surface?

I have used both internal and external arrangements. A plastic or plywood arm with the end of the rod epoxied into a hole in it is something I have used. Also a wire epoxied into the end of the rod will work. If you chose that arrangement, I think a notch in the end of the tube with the vertical part of the wire emerging from the notch would be stronger and more reliable than having the bend outside of the tube.

A test before you install it would be useful. I hope this is clear - I don't have anything accessible that I could photograph. - other than the picture I made of that N-ll during recovering.
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Old Mar 27, 2012, 03:21 PM
I don't like your altitude
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Thanks Herks,the notch is the missing piece!A short say 5mm piece of thin walled 4mm I/d tube over that and I think it will be pretty much reliable.And it will get well tested before installation!
Many thanks Stuart
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Old Mar 27, 2012, 04:28 PM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
3,325 Posts
Just a quick prototype.the arm is alu,I'll use steel in the next and use a 2mm drill to get a more accurate notch.Thanks again for the tip Herks
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Old Apr 02, 2012, 06:32 AM
I don't like your altitude
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Joined Sep 2011
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Does anybody have any information on the HoXVIII,the variant with the fixed u/c and 4jet pods mounted on the legs.Seems to be called a or b depending on the source.All I can find is on Luft46 and Nurfluegal.com where it states it being based on the HoIII plan form.If,as implied it was being readied for production at the wars end,could there be some more detailed drawings?
Regards Stuart
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Old Apr 02, 2012, 05:10 PM
Deniable plausibility
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Derbyshire, UK
Joined Aug 2008
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Try these. Hope they are of help.
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Old Apr 02, 2012, 05:46 PM
I don't like your altitude
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Thanks Mr Dread Those 3 views look workable.Not much relationship to the III that I can see.Doing some quick measures off the iPad screen 60 mm nacelles for 50 mm fans would give a span of about 2.3m.Now all I need is ............
Regards Stuart
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Last edited by Stupot46; Apr 02, 2012 at 06:04 PM.
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Old Apr 03, 2012, 03:51 PM
I don't like your altitude
Stupot46's Avatar
Joined Sep 2011
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The more I look at this the more I become convinced that it will be my next project.IF as with the Volksjager,I can find someone prepared to do the design work.
The drawing has some nice details- the differing positions of the nacelles from inboard to out board,what appears to be a scoop out of the wing above the intake.And of course the clam shell doors over the 4 wheeled gear.
I wouldn't think there would be any serious aerodynamic problems with this one,but would appreciate comments from the "committee"
The change in angle on the leading edge is a feature that also appears on the X,is there a reason for this?(this would be an obvious line for outer wing panel attachment.
Regards Stuart
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Old Apr 03, 2012, 04:38 PM
Deniable plausibility
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Joined Aug 2008
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Or you could do the 'b' version. It has a fin...
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Old Apr 03, 2012, 05:48 PM
I don't like your altitude
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I seem to recall a build of this(maybe s/b edfs) I've never been fond of the fin;I don't think the Hortens were either.The six motors buried in the wing and the position of the intakes would need some nifty ductwork .
There looks to be more relationship with the III in this one.I presume the original design would be similar to this minus the fin.Then you run into the same problems as the IX.
Sorry,not tempted.
Regards Stuart
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Old Apr 24, 2012, 07:09 AM
I don't like your altitude
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3,325 Posts
I was asking Jens earlier how he determined the thrust angle on his mini wing.His answer was way to technicalso I thought I'd ask the Q here.I can see that the angle would need to be greater for a more symmetrical foil as opposed to the Clark that Jens is using.Is there a specific method used to arrive at the optimum?
Stuart
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Old Apr 24, 2012, 07:26 AM
Deniable plausibility
Shedofdread's Avatar
Derbyshire, UK
Joined Aug 2008
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For me, the way forward is adjustable motor mounts....

Seriously, there's so many variables that to get it 'spot-on' first time would require such a detailed analysis of the proposed design that IMHO life's too short.

Sorry, probably not what you wanted to read, eh?

Richard
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Old Apr 24, 2012, 07:48 AM
Herk
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Virginia USA
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The best way to visualize it is to ask "where is the drag produced, and where is the thrust aimed." If they are not aligned then whatever adjustment you make, it will only be just right for one speed and power setting. To be able to adjust the thrust line allows fine tuning of the setup. Probably that's more effective than analysis.
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Old Apr 24, 2012, 09:33 AM
internet gadfly
nmasters's Avatar
Colorado
Joined Aug 2006
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Quote:
Originally Posted by Shedofdread View Post
For me, the way forward is adjustable motor mounts....

Seriously, there's so many variables that to get it 'spot-on' first time would require such a detailed analysis of the proposed design that IMHO life's too short.
Skip the mathematical analysis, just weigh it. Seriously models are light enough that the easiest way to find the 3D center of gravity is to hang it by the prop shaft and LOOK at where the string points. sense you already have the CG on the horizontal plane all you have to do is find the point where the string line intersects that point to get the 3D location.

--Norm
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