#11
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Revised Plan -- Freewind BG Mk IB
OK, I'm listening about the dihedral issue.
The new Mk IB goes back to the original Mk I plan, but increases the wingspan to 14", and the dihedral to 15 degrees. The wingtip chord is shortened to 1.75", but the wing root remains the same.
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#12
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Revised Plan -- Freewind BG Mk IIIB
And here's the Mk IIIB, with the polyhedral tips. Same wingspan, but the first dihedral is now 15 degrees, and the tips have been adjusted to match the original 90 degrees (relative to each other).
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#13
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Mark IB looks good - but you still might want to flip the tail upside down - from my reading on the subject, that will increase the stability of the boost (right now it's like having three fins on one side of the rocket and none on the other).
Mark IIIB looks sharp, but you might have too much dihedral in it. The sources I've studied on boost gliders (I don't claim to be an expert) have all said a total of 15 degrees is what you want - For example, if you have a three section wing (flat plane in the center and two dihedralled tips), you want each section to have a dihedral of 7.5 degrees. So, with your four section wing, you'd want each section to be 5 degrees from the next. The more sections of dihedral you have, the closer you are approaching elliptical dihedral (where the whole wing is just a smooth curve) Just for clarification, this is an example of elliptical dihedral: http://www.ehobbies.com/pkz4700.html If you haven't been there yet, you might want to check out the Rocket Boost Gliders Yahoo group: http://groups.yahoo.com/group/rocketboostgliders/ A lot of the boost glider (from small gliders to RCRG) gurus hang out there and throw around a lot of good info there. I am just an unworthy novice compared to them! Greg |
#14
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Quote:
Thanks for the additional info, Greg. I'll put the Mk IV and Mk IIIC up shortly, with these improvements. ADDENDUM: They now have their own Mk numbers -- IV and V... Actually, I already listen in to the Yahoo BG group. I need to look back through the message queue to see if I can find something.
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 Last edited by CPMcGraw : 03-18-2010 at 03:25 PM. |
#15
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Update -- Mk IV
Following Greg's suggestions, here is the Freewind BG Mk IV.
The vertical fins are now below the stabilizer line, with some trim fins above. The stabilizer mounts to the top of the fuselage, and the wings remain at 15 degrees.
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#16
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Update -- Mk V
And now, the Mk V, with both polyhedral wings and inverted vertical tailfins. The main wings are set at 83 degrees, and the tips are at 75, for a total of 15 degrees back from 90. (The total wing dihedral is 30, from tip to tip.) The horizontal stabilizer is attached to the bottom of the fuselage.
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#17
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Update -- Mk VB
Same design as the Mk V, but with the dihedral at a total of 15 degrees (each panel joint at 5 degrees).
__________________
Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#18
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Time to start building, Craig!
Greg |
#19
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Quote:
Yeah, I know...
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
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