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philr

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Dec 26, 2020
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99
I did preliminary weight and balance and moved the wing aft to adjust balance. The fuse wing attach points were for a wing with a smaller D-tube so the front carry through moved back quite a bit.
1625009780828.png
 

TLAR

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Sep 29, 2020
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Adding dimensions to the drawing is a lot of work!
Much appreciated!
Thanks again for sharing!
 

philr

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Dec 26, 2020
Messages
99
Adding dimensions to the drawing is a lot of work!
Much appreciated!
Thanks again for sharing!
Sure no problem. The full plans are on my google drive and shared public so anyone can see them what I posted here are just snippets. Here is a link. HERO PLANS
 

pylon500

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Dec 26, 2003
Messages
395
Location
Taree Airport Australia
Working on the horizontal stabilizer design
View attachment 112523
Just looking at your tail set-up and will make a few observations.
The dynamics of the belcrank/tail movement as shown will give you more up elevator than down elevator, due to the relationship between the belcrank and the tail's pivot point...
I was going to suggest some offset (downwards) to the drive arm of the belcrank, but in hindsight, you've probably got this about right. As with most stabilator setups, you generally want more up travel than down travel because of you wing's pitching moment...
Have you drawn this in the various travel positions?, moving a belcrank over that much angle (dotted) with cables is going to create some weird effects.
Are you considering an 'anti' servo tab?
 

philr

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Joined
Dec 26, 2020
Messages
99
Just looking at your tail set-up and will make a few observations.
The dynamics of the belcrank/tail movement as shown will give you more up elevator than down elevator, due to the relationship between the belcrank and the tail's pivot point...
I was going to suggest some offset (downwards) to the drive arm of the belcrank, but in hindsight, you've probably got this about right. As with most stabilator setups, you generally want more up travel than down travel because of you wing's pitching moment...
Have you drawn this in the various travel positions?, moving a belcrank over that much angle (dotted) with cables is going to create some weird effects.
Are you considering an 'anti' servo tab?
I think that we need around 8 degrees of travel. I sketched that just to kind of figure out how to build because the stab needs to come off for transport so I am planning to use a bell crank with a pushrod and then removal is much easier than if I had 2 cables to detach each time. Looking for examples of flying stab throws for confirmation on this. Anti servo tab is on top of my list of wants..gotta see if we can make part 103 first with a 1/2 VW but I definitely want one.
 

philr

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Dec 26, 2020
Messages
99
This is the only set of plans I have seen with a flying stabilizer it is from the Polliwagen and my design is so different.
1625071628084.png
 

pylon500

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Dec 26, 2003
Messages
395
Location
Taree Airport Australia
This is the only set of plans I have seen with a flying stabilizer it is from the Polliwagen and my design is so different.
View attachment 112551
Bare in mind this is a fairly swept tail so that pivot point is not really where it seems compared to the cutaway section of the tail.
But the 13º up and 8º degree down is about right.
If you work on the assumption that the general stalling angle of the average wing section is around the 15º point, then you don't want to go beyond that angle (especially in 'down' travel) to avoid tail stall.
That can get messy.
 

philr

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Dec 26, 2020
Messages
99
Bare in mind this is a fairly swept tail so that pivot point is not really where it seems compared to the cutaway section of the tail.
But the 13º up and 8º degree down is about right.
If you work on the assumption that the general stalling angle of the average wing section is around the 15º point, then you don't want to go beyond that angle (especially in 'down' travel) to avoid tail stall.
That can get messy.
I thought maybe there is a formula for this that involves stab area and wing area and wing center of lift to stab center of lift. I am using a much bigger stab than most setups and since there is more stab area I thought control throws would go down. Stab =10'x2' so 20sq ft being deflected is lots of force. The moment is 11.25' center of lift to center of lift. Wing area is 133 sq ft. Not sure but just a gut feeling that the larger the horizontal stab the lower the throws as long as moment stays the same?
 

Victor Bravo

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Jul 30, 2014
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9,578
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KWHP, Los Angeles CA, USA
I am assuming the upper pair of bolts shown also have several other bolts or pins to prevent these (upper) bolts from rotational movement?

What prevents movement or bending/bowing of the zig-zag steel tabs between the upper and lower bolts?
 

philr

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Dec 26, 2020
Messages
99
I am assuming the upper pair of bolts shown also have several other bolts or pins to prevent these (upper) bolts from rotational movement?

What prevents movement or bending/bowing of the zig-zag steel tabs between the upper and lower bolts?
Good questions. The upright rivited to the rib has a 90 degree bend on top to prevent that connection turning. The zig zag steel maybe its a bad idea or just upsize it and straighten out the bend so its much less than 90?
 

philr

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Dec 26, 2020
Messages
99
Good questions. The upright rivited to the rib has a 90 degree bend on top to prevent that connection turning. The zig zag steel maybe its a bad idea or just upsize it and straighten out the bend so its much less than 90?
Welding something could work.
1625166790661.png
 

philr

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Dec 26, 2020
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99
Slept on it and think this is better what do you all think?
1625250712385.png
 

Victor Bravo

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I think you clearly have two bolts too many. Make the lower two bolts the ones that come apart, and delete the upper bolts and all of the sheet metal connecting the upper and lower bolts.
 

philr

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Dec 26, 2020
Messages
99
I think you clearly have two bolts too many. Make the lower two bolts the ones that come apart, and delete the upper bolts and all of the sheet metal connecting the upper and lower bolts.
I really want the attachment of the stab to not be the actual hinge. I cut the attachment down to 2 bolts per your comments and move everything under the stab to keep it clear of the rudder also this allows for the top to have covering over the attachment area. What do you think?
1625782462108.png
 
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