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  #351  
Old 01-17-2018, 12:56 PM
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sahrens sahrens is offline
 
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Originally Posted by Steve Melton View Post
kicking this idea around with Amanda. maybe something like this?

Why not attach the cone to an appropriate length hex head screw that threads in from the back side to move the cone into the tie down?

Similar to the fuel drain fairing attachment but with the screw end attached to the cone.
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  #352  
Old 01-17-2018, 02:04 PM
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Originally Posted by Bevan View Post
All this fantastic manufacturing technology is great, but has anyone calculated anticipated drag reduction and therefore increased speed?

Bevan
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Originally Posted by Steve Melton View Post
I have not, but I am working to get CFD up and running to make an assessment.
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Originally Posted by control View Post
As it it less than 20$ in plastic and other parts if you already have a 3D-printer, I am fine with skipping the calcs and settle for testing... anything above 3 knots for the drain and flap attachment fairing would make me think it is worth it
I know all of this is for fun, education and, well, because we can. Given that, my unsolicited thoughts: The real question really isn't what is the drag delta from the faired tie down vs non-faired tie down ring. The real question is what is the drag reduction delta of the faired ring vs removing the ring? Is it enough to merit adding this fairing? The truth of the matter is this fairing is thought up for the purpose of keeping one from having to always remove the tie down rings. If removing the tie down decreases the drag greater than does this fairing, is the cost of the fairing justified? In $$ and in effort? I know which I would choose if the fairing increases drag from that of no ring attached?
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  #353  
Old 01-17-2018, 02:11 PM
John-G John-G is offline
 
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Steve-
First the disclaimer …. don’t own a 3D printer and know nothing about creating 3D CAD drawings, but I’m very interested in learning more about the process so have been watching this thread.

Just a thought about how one could assemble the cone/shaft assembly into the suggested housing for the tie down. The cone/shaft that goes into the tie down housing could be made from two pieces with the end of the shaft having four teeth on it that would be inserted into the cone and lock into a grove inside the cone. Once pushed in place, the teeth on the end of the shaft would provide a one-time push on assembly (but no removal). One can get an idea of what I have in mind by looking at the following photo. The locking end of the shaft could look something like the following photo but with four well defined catches instead of the two shown in the photo. After all the parts are printed the spring and cone can be installed in the housing then the shaft with the catches inserted and locked into the cone.
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Last edited by John-G : 01-17-2018 at 06:22 PM.
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  #354  
Old 01-17-2018, 05:50 PM
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Snowflake Snowflake is offline
 
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Quote:
Originally Posted by Bevan View Post
All this fantastic manufacturing technology is great, but has anyone calculated anticipated drag reduction and therefore increased speed?
One knot per SPF. That's Small Plastic Fairing. So add as many as you can, to everything that sticks out...
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  #355  
Old 01-17-2018, 07:33 PM
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I like it. SPF.
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see Amanda Melton for www.rvplasticparts.com
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  #356  
Old 01-18-2018, 01:19 AM
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And soon you'll be able to create a rating scale for aircraft based on how many of your cool fairings are installed. SPF 50 being much faster than SPF 25, eh!

Cheers,
Bob

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Originally Posted by Steve Melton View Post
I like it. SPF.
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  #357  
Old 01-18-2018, 10:46 AM
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TCONROY TCONROY is offline
 
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JD Airparts makes a similar fairing for the fuel tank drain sump and fuel vents. This would be a great addition for the tie-downs.
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  #358  
Old 01-18-2018, 03:39 PM
whodja whodja is offline
 
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Default Tie down cover

How about a cover with a spring loaded hinge in front of the tie down. Adhere to the wing surface with proseal.
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  #359  
Old 01-19-2018, 06:04 PM
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Default needs some work

clearly this one needs some work. it was easily removable with one hand in about 2 seconds. it positively locked to the eyebolt.









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Cincinnati, OH
RV-9A, Tip-up, Superior O-320, roller lifters, 160HP, WW 200RV, dual impulse slick mags, oil pressure = 65 psi, EGT = 1300F, flight hours = 600+ for all

Simplicity is the art in design.

see Amanda Melton for www.rvplasticparts.com

Last edited by Steve Melton : 01-19-2018 at 09:46 PM.
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  #360  
Old 01-19-2018, 09:31 PM
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Steve Melton Steve Melton is offline
 
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Default concept 1 rev 2

optimized use of space. recessed eyebolt to actual condition to ensure positive contact of fairing to wing skin.

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Steve Melton
Cincinnati, OH
RV-9A, Tip-up, Superior O-320, roller lifters, 160HP, WW 200RV, dual impulse slick mags, oil pressure = 65 psi, EGT = 1300F, flight hours = 600+ for all

Simplicity is the art in design.

see Amanda Melton for www.rvplasticparts.com

Last edited by Steve Melton : 01-19-2018 at 09:37 PM.
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