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KITFOX RIBS

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Posted (edited)

Here are drawings of the Kitfox 2 and 4 ribs for comparison, including the rib for my Leading Edge extension and the modification line for the rear portion of the Kitfox 2 rib to make it comparable to the Kitfox 4, or Harry Riblett modification explained in Doug's post on "VGs on Bottom...".

You can copy this and take it to a copy shop for a full sized print. Just have them enlarge it to match the yardstick with your measuring device.

My lines may look crooked, because the paper was not flat enough.

Hope this helps someone make better ribs from the undercambered ones to give a better cruise speed for their bird.

EDMOpost-399-0-53995100-1375496577_thumb.jpg

Edited by Ed In Missouri

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Posted

Thanks Ed for the post

Bob

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Posted

Thanks Ed.

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Posted

I ordered new capstrips and more 9460 today - will post a photo or two when I do my first "experimental modified rib".

I am doing an old rib first before changing the ones on the wings.

EDMO

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Posted

Hi,

    have damaged Avid speed wing ,do you know where I can obtain a rib drawing from?

Or replacment ribs.

Thanks

Chaz

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Posted

Hi,

    have damaged Avid speed wing ,do you know where I can obtain a rib drawing from?

Or replacment ribs.

Thanks

Chaz

You might get more responses if you start a new topic here and label it "Avid Ribs" - Think the Avids outnumber the Kitfoxes on here.

EDMO

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Posted

I would take one of the ribs and piece it back together, or remove a good rib and use it for a pattern.  I dont know of anyone locally I could get a good pattern from to send to you, all the guys I know here have the STOL ribs.

 

:BC:

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Posted

Ed where did you order your capstrips and if you don t mind me asking what did it cost you?

thanks Bob

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Posted (edited)

Ed where did you order your capstrips and if you don t mind me asking what did it cost you?

thanks Bob

Bob, I got them from Spruce - 1/8 x 1 inch @ .55 a foot - I wanted 38 inches, and the order-taker said if I ordered it that was it would cost me another foot for the 2 inches over 3 feet - but she modified my order to the total number of feet I needed to save me money, and said they would cut it at 38 inches each piece. I think Wicks wanted .85 per foot? I could have cut them out of plywood cheaper, but trying to get this bird done and just went with the easiest.

EDMO

If you are planning to modify your undercamber ribs, then I need to say that I am using the full capstrips on the ribs that don't support the "flaps/ailerons", and on the supporting ribs I am not cutting the web, so I don't weaken the support, but using capstrips back to the spar, and adding aluminum angles on each side of web from there back to the trailing edge.

I will post some photos when I get the first rib done.

ED

Edited by Ed In Missouri

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Posted

thanks Ed for the reply I was looking at the price for aircraft spruce and wicks I was hopeing that there were a cheaper route than ordering from either place I have done the calculating of the 2 wings and come up with 245 feet of capstrip you had mention about cutting your own.... would you cut from 1/8 plywood and if so what kind. I don t have a problem doing this if it would be cheaper and just as good as the capstrip

thanks Bob

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Posted (edited)

thanks Ed for the reply I was looking at the price for aircraft spruce and wicks I was hopeing that there were a cheaper route than ordering from either place I have done the calculating of the 2 wings and come up with 245 feet of capstrip you had mention about cutting your own.... would you cut from 1/8 plywood and if so what kind. I don t have a problem doing this if it would be cheaper and just as good as the capstrip

thanks Bob

Bob,

I would look at the (Finland? / Russian?) 3 mm plywood with lots of plies in Spruce, or some other "aircraft/marine" type. Don't think the cheap stuff from Home Depot or Lowes will do in this case. I have used this plywood for capstrips, and 1mm leading edge covering and 1/4 inch (5 or 6mm) for rib webs. It is a little more costly than some other plywoods, but it sure is good, IMO. If you need to go cheaper, then some other plywood from Spruce - Your shipping should be cheaper than mine.

EDMO

Edited by Ed In Missouri

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Posted

That looks like it is only 3 layer ply.  You want 5-7 layer ply.  http://shop.balsausa.com/category_s/68.htm  1/8" X 12" X 48" 5 ply for 23 bucks a sheet...

 

:BC:

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Posted

Also, I would look around your area and see if anyone does any laser cutting.  I had a kit made for a model of the SS minnow and they cut me a bazilion strips for a little bit of nothing, and you have virtually no waste.

 

:BC:

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Posted

That looks like it is only 3 layer ply.  You want 5-7 layer ply.  http://shop.balsausa.com/category_s/68.htm  1/8" X 12" X 48" 5 ply for 23 bucks a sheet...

 

:BC:

I agree with Leni - The more plys the better - believe the 1/4 inch is like 7 ply - I bought the 1mm for my leading edges in 2' x 4' sheets - The 1/4 or 5mm came in 5' square sheets, if I remember right - check out the spruce catalog - there is a chart which gives you the plys and sizes and cutting for shipping, etc. Maybe you have a better place, but I know I can depend on Spruce and they are real close to you - And there are no defects in it - You could drive up there

EDMO

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Posted

Brett has come back and said he can sort me Avid ribs ....so looking good. :)

Thanks for offer of help and ideas.

 

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Posted

Here are drawings of the Kitfox 2 and 4 ribs for comparison, including the rib for my Leading Edge extension and the modification line for the rear portion of the Kitfox 2 rib to make it comparable to the Kitfox 4, or Harry Riblett modification explained in Doug's post on "VGs on Bottom...".

You can copy this and take it to a copy shop for a full sized print. Just have them enlarge it to match the yardstick with your measuring device.

My lines may look crooked, because the paper was not flat enough.

Hope this helps someone make better ribs from the undercambered ones to give a better cruise speed for their bird.

EDMOattachicon.gifIMG_1520.JPG

I got my new capstrips today and in checking measurements, I am going to have to replace or extend my jury strut rear spar attachment when I do the Riblett modification like the Kitfox 4. Will post some photos as soon as I get a couple of rib examples done.

EDMO

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Posted (edited)

Here are drawings of the Kitfox 2 and 4 ribs for comparison, including the rib for my Leading Edge extension and the modification line for the rear portion of the Kitfox 2 rib to make it comparable to the Kitfox 4, or Harry Riblett modification explained in Doug's post on "VGs on Bottom...".

You can copy this and take it to a copy shop for a full sized print. Just have them enlarge it to match the yardstick with your measuring device.

My lines may look crooked, because the paper was not flat enough.

Hope this helps someone make better ribs from the undercambered ones to give a better cruise speed for their bird.

EDMOattachicon.gifIMG_1520.JPG  Note: Server says this does not exist - Oct. 2015.  See "Kitfox Ribs".  EdMO

If you are modifying the Eppler undercambered ribs per the Riblett mod, or making Kitfox 4 wings, BE AWARE that your jury strut fittings will have to be longer, especially on the rear spar, and possibly your strut fittings too. MEASURE CAREFULLY - I know I am going to have to modify my rear jury strut fittings and make them longer. I think I have an extension mod planned.

I will soon be posting some photos of an experimental rib with the conversion. Stay tuned....

EDMO

Edited by EDMO

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Posted

Can't wait for the pics.  I may just do this to my wings instead of using the KF IV ribs.  It would not take much to reshape the bottom of the wing and re-cover it.  Take a look at the jury struts that Carlson Aircraft have.  I was planning on using these on mine for the tail braces one of these days too.

 

http://www.carlsonaircraft.com/struts.html

 

 

:BC:

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Posted (edited)

Can't wait for the pics.  I may just do this to my wings instead of using the KF IV ribs.  It would not take much to reshape the bottom of the wing and re-cover it.  Take a look at the jury struts that Carlson Aircraft have.  I was planning on using these on mine for the tail braces one of these days too.

 

http://www.carlsonaircraft.com/struts.html

 

 

:BC:

Leni,  Sorry for the wait on posting a picture of my modified Riblett ribs - I think I had posted this earlier somewhere - Just found out that I had not finished this thread.  I saw that others were reading it.   I used 9460 for the additions and leading edge extensions instead of buying more T88.  Here is a photo.   EDMO

Modifying wing ribs 2.JPG

Edited by EDMO
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