Cub Flyer Fresno

Yes, that's a Sig 1/4 scale full wing, not clipped. The front tubing is 3/4" and the rear is 5/8", although the rear could have been 1/2" to be closer to scale. The ends were made from scrape aluminum I pick up at work and (before I bought my belt/disk sander) were made by hacksawing and filing to shape. That's the part that was A LOT OF WORK! And that's also the time I decided to invest in a belt/disk sander! Not that much money from Harbor Freight.

spaceworm

I would not use the KS aluminum streamline cross section (CS) tubing without internal stiffening. Hardwood dowels inserted the full length and epoxied at the ends will do the job. However, the FS J3 Cubs i have seen and the FS detail drawings I have seen on replacement parts listings show the struts not as streamline CS, but as rectangular CS with full radius edges. Were later J3 Cubs or maybe the Super Cubs fitted with streamline CS struts? Thanks.

FlyerInOKC

My Feedback: (6)

Stiffening can't hurt. I think some sort of end like Cub Flyer in Fresno used is called for. I may revisit the subject a little closer to spring if I ever get my current project done.

John_M_

Thats pretty much how the Hanger9 struts are... the front is 15/16 and the rear is 3/4... they are a bit off scale, but it all depends on what you are using for reference... the original tear drop struts were smaller than the replacement streamline struts that are available for the Full sized cub... so the hanger9 are within range.

Original Tear Drop (egg) Shaped Struts---- Full Size Cub

The J3 front strut has a 2.406 major axis x a 1.377 minor axis.
The J3 rear strut has a 1.780 major axis x a 1.060 minor axis
The jury struts are 1.473 major axis x a 0.492 minor axis.
The spreader tube is 0.500 od.

Sealed Replacement Streamline Struts---- Full Size Cub

The J3 front strut has a 3.938 major axis x a 1.375 minor axis.
The J3 rear strut has a 2.362 major axis x a 1.000 minor axis
The jury struts are 1.560 major axis x a 0.550 minor axis.
The spreader tube is 0.500 od.

The H9 struts are 6061 aluminium t6 hard... they are stiff and strong on their own... the only issue I had was the ends were loose and I didn't like the soft aluminum clevis they provided to attach to strut end to the fuse... I saw a youtube video where one of the struts actually pulled off the fuse... luckily they managed to land it with only some minor damage... I ended up drilling out the pins that held the ends in, and reset the wing mount ends back in with some JB weld and a couple of 2/56 screws that passed all the way through the strut and inserts, then cut and ground the screws flush with the surface of the strut... then I totally re-worked the fuselage end of the struts and made all new hardware from some stainless steel bits I got from the hardware store.

John M,

sj3cub

My Feedback: (9)

Wow, Those strut ends are really nice. You have worked your butt off fabbing those. Beautiful job!!!

Cub Flyer Fresno

Thanks sj3cub. All that work lead to a good thing, the purchase of a belt/disc sander. Now I can't imagine being without it!

Murphey

My Feedback: (11)

Have you ever heard of “Paralysis by Analysis? “ Well that’s what I’ve experienced in my quest to modify this already built ¼ scale Sig Cub to have a working door/window. I read all of the threads, studied the plans, build manual and spent countless hours staring at the fuselage…and not really getting anywhere…“Paralysis by Analysis”. So Last night, I finally decided to just move forward and “get ‘er done”. So I cut out the door and that in itself was progress! I’ve come to the conclusion (Thanks John M and CFF) that the main wing loading is transferred to the fuselage through F5 and F7 and that the cabin top and the center stringer/fuse side, now removed, served to add rigidity to the fuselage. So I plan to replace that rigidity with a spruce stringer that runs beneath the bottom of the door cutout from F5 to F7 and make a plywood cabin top. I will keep the spruce cabin top and cut away the balsa that’s laminated to it. Of course I don’t want the entire top of the cabin to be a solid piece of ply so most of it will be cut out. Now, with the exception of the door cutout, all of this is theory…but I think it will work. I’ll post a photo or two when I’m making “real” progress.
M

FlyerInOKC

My Feedback: (6)

I can't wait to see the pictures Murphey!

John_M_

Well done Muphey, you're one step ahead of me... I'm still planning it out as you have done... I'm way past the “Paralysis by Analysis”, I think insanity is setting in, LoL.... you are doing it the right way, just get in there and do it.... I'm going to do Cub Man's music wire re-enforcement, with couple of tabs added, made from some brass stock, silver soldered to the music wire right at F-5 (one either side) to tie the remainder of F-5 to the music wire / Cabane's... the tabs will be basically a piece of brass with a hole drilled the same size as the music wire and soldered in place, then attached to F-5 with a couple 4-40 Flathead screws / nuts (Flatheads facing the wing) ... the tabs will be hidden under the two cabin balsa blocks that are glued to the forward side of F-5... I'm going to leave F-7 along... take the long side pieces away from F-6... the music wire will be tied into the fuse at the bottom at F-6, run up the vertical window pillar at F-6 to the Cabane's; along the Cabane's past F-5 (but tied into F-5 with the brass tabs) and down the forward window stay and into the fuse... then remove the long sides form F-5.... I know I'm being anal, but it will make me feel it is secured with the tabs.

***Edited*** the music wire will be hidden inside the Piller's, Stay's and Cabane's


John M,

John_M_

Something like this... I don't have a cad program, so I just drew it up in paint... the green dot is the music wire, its not to scale so it will be bigger, at least 5/32 - 3/16 wire.


John M,

Mako17

Anyone know where one can purchase the side windows for the Anniversary Cub? I recieved this kit partially built and its missing the windows and Cowl. I'm going to purchase the fiberglass Cowl from FG Specialties.Thanks for your help.

FlyerInOKC

My Feedback: (6)

If its a SIG Cub from SIG.

If its a Goldberg Cub or Great Planes Cub from Great Planes.

You can order direct or thru a local hobby shop if you have one in your area. Both companies have excellent customer service!

Twin_Flyer

My Feedback: (4)

You will have to call Tower Hobbies. They still list the kit as being available, but no individual parts are listed.

Here are the part numbers from the Goldberg website, maybe they can help over the phone.

http://www.carlgoldbergproducts.com/.../gpma0963.html

I looked at the manual and it really doesn't say much about them. Are they preformed or flat sheet? if flat sheet, like the windshield, you can use any plastic from your LHS to replace them.

maybe post on one of the actuall Goldberg Anniversary cub threads for more info?

https://www.google.com/search?client...67.nZRZxc4K4CI

HTH,
Bill S.

spaceworm

Hi John,

I have been using a FREE 2D Cad program that is compatible with ICad. It is called "intellicad" and was given free to entice users to buy their 3D cad software. I am not well versed in ICad but had no real problem using intellicad. I just kept pulling down the menu selections until I found the one I wanted. Give it a try. I have used it to dimension a scanned part like a firewall so I can add holes to use for a drilling template. Also good for getting an unshown dimension from a scaled drawing after scanning that drawing.

Enjoy!

acdii

Getting closer to Covering! Have both full wings assembled, just have to finish the ailerons and servo mounts! Have the left Clipped wing done too, with aileron and servo mounted. I should be able to knock out the aileron and servo mounts in an hour then move onto the struts. Eager to try out the Koverall.

John_M_

Thanks for the heads up on the intellicad, I'll look into it... I usually use Adobe Acrobat Pro to get dimension off drawings and plans, but the .pdf files must be formatted with the scale information...

That's interesting; building both sets of wings, two aircraft's, in one... great idea !

John M,

FlyerInOKC

My Feedback: (6)

Richard (Mako17)

Here is a link to the parts list for a Goldberg: http://www.carlgoldbergproducts.com/...pma0963.html#1

The K-63 Side Window (set) is on the second line Part # 1611 and the retail price is $21.96. You can use this information to order from Tower Hobbies or any other Goldberg/Great Planes dealer.

ThunderBoat42

My Feedback: (1)

Tower is pretty good about keeping the parts. They even had some parts I needed for the GB Extra 300 which has been discontinued for several years.
I'm also building an original Anniversary Cub.

Mako17

thanks for the info guys, i'll give the evil empire a call tomorrow.

ThunderBoat42

My Feedback: (1)

You're in Enterprise? I work there a couple of days a month.

Mako17

Yes sir I live in Enterprise, I fly with Wiregrass RC. So what are you in E'prise for?

Cub Man

My Feedback: (50)

Guys i'm sorry but a lot of the early cub den pages were after thoughts. I wish I had taken a bunch of photos to add to the pages. The wire setup in the open door and windows adds a lot of strength into the structure. I'm redoing the site, so if anyone has some good photos, send them to my email and they may be added to the update....

Murphey

My Feedback: (11)

I’ve made some progress! I cut out the door opening, installed a hardwood rail on the bottom of the opening and balsa on the aft side. Then I lined the opening with 1/32” ply. To reinforce the fuselage, hopefully making up for the loss of rigidity by cutting out the door, I first cut out the balsa laminated to the spruce cabin top then added the ply stiffeners to the cabin top. This will also replace the wing mooring blocks. ¼” blind nuts will be used instead of the threaded wood blocks. So with apologies to Cub-Man and the wire method, I think there is more than 1 way to skin a cat…or modify a Cub.
I’m also in the process of making a door…but slipped back into the “paralysis by analysis” mode because I would really like the working door latch but will most likely make a couple prototypes first…
M

John_M_

Very Nice Murphey!... that will definitely tie F-5 into the Cabane's... I may replace the F5G gussets with a piece plywood, I'll cross that path when I get there... but I think what you have done really boxes that fuse in nicely.

Here's what I've done so far... I haven't cut the door out yet, but its marked and ready to go... got a bit of glare from the flash (old sucky camera)... 3/16 music wire... 3/8 x 1-3/4" .067 brass tabs... I will cut and bend the wire 90 degrees, and poke them through some holes drilled through the plywood sides on the fuse, and then set in epoxy.

John M

Murphey

My Feedback: (11)

John: Do the brass tabs attach to F5G?