Sight Gauges

Big Ed

N50247 - '79 Super D
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My old Decathlon CS had an aerobatic sighting device, but my current Super D does not. I've started to practice the 2021 Sportsman figures and it is very clear I am going to need one. Quickly setting an accurate 45 line on a Cuban 8 is particularly challenging without a gauge. Likewise for verticals, which are closely watched by judges.

Greg Koontz advertises sight gauges for $595. Not too expensive as aircraft parts go, but also seems excessive for what it is.

Anyone aware of any alternatives out there?

I read in an article somewhere that Patty Wagstaff used electrical tape on her window. That would probably work fine for setting angles. Might not be precise enough for leveling wings during vertical lines. Perhaps tape on the underside of the wing for that?
 

DanO

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I went with the Greg Koontz option. It’s what Patty W. has on their Super D. It’s expensive but well-designed and engineered. And, I agree it is an particularly helpful for acro in the Super D.
 

Big Ed

N50247 - '79 Super D
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I went with the Greg Koontz option. It’s what Patty W. has on their Super D. It’s expensive but well-designed and engineered. And, I agree it is an particularly helpful for acro in the Super D.
Can you share a photo?

Probably gonna buy a chute from Greg in near future anyways.
 

DanO

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No adjustments. It is made to fit this very specific spot on the struts. Very well made. I'll take some closeups of it this afternoon when I at my hanger and I'll poet those these evening. Actually I was very pleasntly surprised when I got it to find how well it was designed and made.
 

Big Ed

N50247 - '79 Super D
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Thanks, will look forward to seeing pics.

A bit surprised at no adjustment. Would think the middle fixture would need to slide forward and back on the horizontal member, in order to precisely align the vertical member with the pilot's seating position.

I have never judged, but I have been told that judges can see as little as a degree of yaw on a vertical line. Bart?
 

Bob Turner

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Unlikely. A macinist may be able to see such minor deviations on a work piece, but aero is dynamic. Things sre always moving. Maybe 3 or 4 degrees, but not one.
 

Hiperbiper

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Always used fine line painting tape on the windows...🙃
It's only a reference, no one on the ground can tell 5-10* viewing parallax with any regularity.
This is sometimes the problem when judges are watching different airplanes preform the same routine; an Extra can do a pure vertical roll due to it's build. The same vertical line in a high wing airplane will look off vertical due to the high wing. Throw in a high wing airplane with a flat bottom wing and dihedral and what seems in the cockpit to be vertical will look like the plane going on it's back (over) from the ground.
See if the tape works for you...if not, consider $600.00 out of your wallet will definitely lighten the airframe and improve performance...😊

Chris
 

Big Ed

N50247 - '79 Super D
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Great pics, thanks for posting! Looks like a very nice device.

What kind of fasteners are the 8 indents on the center piece? Some kind of rivet? Is the other side the same, or some kind of allen screw?
 

Big Ed

N50247 - '79 Super D
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Messages
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Always used fine line painting tape on the windows...🙃
It's only a reference, no one on the ground can tell 5-10* viewing parallax with any regularity.
This is sometimes the problem when judges are watching different airplanes preform the same routine; an Extra can do a pure vertical roll due to it's build. The same vertical line in a high wing airplane will look off vertical due to the high wing. Throw in a high wing airplane with a flat bottom wing and dihedral and what seems in the cockpit to be vertical will look like the plane going on it's back (over) from the ground.
See if the tape works for you...if not, consider $600.00 out of your wallet will definitely lighten the airframe and improve performance...😊

Chris
That's where ground coaching to calibrate the device comes in. Keep flying verticals and adjusting the device until the coach says you look dead vertical from the judges POV.

Not that I have a coach, or probably ever will. But if I did, that's the kind of stuff I imagine he might do. :unsure:

I am going to try the tape on the windows. I suspect that will work great for 45's and pitch adjustment in vertical. From reading comments by others, I think perhaps the precision of that method may be insufficient to detect yaw in vertical. I might try a strip of duct tape on the underside of the wingtip for that.
 

DanO

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Great pics, thanks for posting! Looks like a very nice device.

What kind of fasteners are the 8 indents on the center piece? Some kind of rivet? Is the other side the same, or some kind of allen screw?
Allen screws. Actually, all Allen screws, in two sizes, small and smaller!
 

Big Ed

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Allen screws. Actually, all Allen screws, in two sizes, small and smaller!
Hmmm, so if you loosened the allen screws, could you slide the center piece along the horizontal rod? Or do all the rods terminate in the center?
 

DanO

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All terminate in the center. It comes assembled (with “top” and “front” labeled), save for the fore and aft pieces (the bullet looking things) that attach to the strut supports and they are each milled specifically for fore or aft.
 

Big Ed

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Hmmm. Too bad they didn't drill the horizontal hole thru and use a single rod. Then you could loosen those two Allen screws and slide the assembly fore and aft to fine tune wings level on vertical lines.
 

Hiperbiper

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Hmmm. Too bad they didn't drill the horizontal hole thru and use a single rod. Then you could loosen those two Allen screws and slide the assembly fore and aft to fine tune wings level on vertical lines.
There has to be some fore/aft adjustment with the sight. I'd bet if both grub screws were loose the center of the star will shift back and forth. Otherwise it would only work for one sized pilot...
I remember many moons ago someone had a cool sighting device in a Decathlon; .060 clear plastic with the lines drawn on it. It was attached to the windows (one each side) using small suction cups...
Simple, adjustable and removable.
Today Velcro would work better than suction cups...

Might be something to play with...

Chris
 

DanO

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I‘m sure that GK Airshows could answer the question and provide insight. Above my pay grade.
 

Big Ed

N50247 - '79 Super D
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I‘m sure that GK Airshows could answer the question and provide insight. Above my pay grade.
I plan to visit GK to buy a chute at some point this summer or fall ... unless I stumble across a used seat chute for sale.
 
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