help with j3 kitten spar attachment

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skeeler

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Jul 25, 2021
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7
I am in need of a picture of a j3 kitten spar attachment bracket. I have old plans and no written explanation of the piece that attaches to the spar. I.. can barely see the piece on the plans. Any help would be greatly appreciated. I dont know if my plans are for the folding wing or not. Thank you Sccott
 

GeeZee

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I don't have Kitten plans any better than yours but did download the N3 Pup plans from flyperceptor.com. You have to be approved but that only took a day.
Anyway seems that a lot of people say they are essentially the same? I don't know so take this for what it's worth... here is the "fittings" page from the N3 pup plans. It shows the front and rear spar fittings (again for the N3 Pup).
 

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skeeler

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Jul 25, 2021
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thank you. mine show what i believe to be a nested pipe that slides into the fuselage frame. it shows a solid alum bar with a channel milled but it has a part I cant t tell exactly how its made. shows a solid piece that looks like a roller milled into one end. these plans are so faded and light I cant hardly make out anything. may move on to something else. been looking at the aerolight 103. and found an eaa chapter that will buid it and they take donations for the build [can take it off taxes that way]
 

GeeZee

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Agree that the copies of kitten plans are almost useless. There is a guy Tim Donk, I think was his name (timdonk.com) that claims to be putting Kitten plans in cad but his site is several years old with no visible progress. He does have an original J3Kitten construction manual that downloadable.
The N3 pup plans are good scans and are legible. I really like the mini cub variants but at least the N3 pup seems like it would be a much bigger project than say the legal Eagle or Skylite. Not that important to me but I don’t think the N3 is part 103 compliant.
 

Hawk81A

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Sep 3, 2021
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39
I had a "Preceptor Ultra Pup". It has extruded spars. The forward attach fittings were stamped "U" channel brackets and a machined aluminum bar that slipped into the front cross tube. After rigging, a hole was drilled through the tube and the bar for the "pin" (an AN-3 bolt IIRC). The U channel brackets were attached to the front spar by AN-3 bolts (maybe they were AN-4, but I think they were 3) The brackets were spaced from the spar by spacer blocks that appeared to be some kind of phelonic or plastic.
The rear fittings were similar, but attached to the fuselage by AN-4 bolts on the inboard end. The AN-4 bolts went through a short piece of tube that was oriented fore and aft and welded into a gusset on the fuselage tubing. It attached to the rear extruded spar by 3 AN-3 bolts as well. Hope this is helpful. Dennis
 

skeeler

Member
Joined
Jul 25, 2021
Messages
7
I had a "Preceptor Ultra Pup". It has extruded spars. The forward attach fittings were stamped "U" channel brackets and a machined aluminum bar that slipped into the front cross tube. After rigging, a hole was drilled through the tube and the bar for the "pin" (an AN-3 bolt IIRC). The U channel brackets were attached to the front spar by AN-3 bolts (maybe they were AN-4, but I think they were 3) The brackets were spaced from the spar by spacer blocks that appeared to be some kind of phelonic or plastic.
The rear fittings were similar, but attached to the fuselage by AN-4 bolts on the inboard end. The AN-4 bolts went through a short piece of tube that was oriented fore and aft and welded into a gusset on the fuselage tubing. It attached to the rear extruded spar by 3 AN-3 bolts as well. Hope this is helpful. Dennis
thank you, from what I can tell these plans call for a nut welded onto the fuselage frame and the spar attachment slides into the frame then is bolted in. But very hard to see and the attachment bar is channeled to accept straps that come off the end of spar. It shows a rounded end on the spar attachment the makes no sense to me.. If there was a stop of some sort in the fuselage tube I could understand the rounded end, it would allow the wings to be swiveled back to fold but there is nothing that shows anything like that. I guess I can design my own setup. one of those Im going to build something even if I half to modify it. I finally have the room and I can build a hangar and Im not getting any younger
 

skeeler

Member
Joined
Jul 25, 2021
Messages
7
I had a "Preceptor Ultra Pup". It has extruded spars. The forward attach fittings were stamped "U" channel brackets and a machined aluminum bar that slipped into the front cross tube. After rigging, a hole was drilled through the tube and the bar for the "pin" (an AN-3 bolt IIRC). The U channel brackets were attached to the front spar by AN-3 bolts (maybe they were AN-4, but I think they were 3) The brackets were spaced from the spar by spacer blocks that appeared to be some kind of phelonic or plastic.
The rear fittings were similar, but attached to the fuselage by AN-4 bolts on the inboard end. The AN-4 bolts went through a short piece of tube that was oriented fore and aft and welded into a gusset on the fuselage tubing. It attached to the rear extruded spar by 3 AN-3 bolts as well. Hope this is helpful. Dennis
Agree that the copies of kitten plans are almost useless. There is a guy Tim Donk, I think was his nal
Agree that the copies of kitten plans are almost useless. There is a guy Tim Donk, I think was his name (timdonk.com) that claims to be putting Kitten plans in cad but his site is several years old with no visible progress. He does have an original J3Kitten construction manual that downloadable.
The N3 pup plans are good scans and are legible. I really like the mini cub variants but at least the N3 pup seems like it would be a much bigger project than say the legal Eagle or Skylite. Not that important to me but I don’t think the N3 is part 103 compliant.
I want to thank you for that website. I went there and was able to get the manual (the plans have been removed). From the manual I was able to figure out what needed to be done, along with the dihedral and washout. I looked at another set of plans from roger mann but its a biplane and I didnt want to take the extra time building two sets of wings. So the j3 kitten is looking like the one. I have the equipment to build my own grass runway ( I built one for my rc planes) but this one will t
 

skeeler

Member
Joined
Jul 25, 2021
Messages
7
I want to thank you for that website. I went there and was able to get the manual (the plans have been removed). From the manual I was able to figure out what needed to be done, along with the dihedral and washout. I looked at another set of plans from roger mann but its a biplane and I didnt want to take the extra time building two sets of wings. So the j3 kitten is looking like the one. I have the equipment to build my own grass runway ( I built one for my rc planes) but this one will take more time. I found a cool leveling attachment for my tractor and it makes the ground baby butt smooth. Ive been looking all over the net for that manual Thank You sooooooo much.
 
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