Eagler's Nest

Airframes => Single Seaters => Topic started by: Brock on September 06, 2024, 11:42:16 AM

Title: HELP: LEXL - plans dimension error?
Post by: Brock on September 06, 2024, 11:42:16 AM
Is there an error in the XL plans for the height/top of station 3?  No doubt this is a known issue but my search skills failed to find the answer.

Page (6) of the fuselage plans calls out 25.375" for the height of station 3 where the top seat tube will reside. Distance from bottom 'level' tube to empennage-'level' tube.

But at station [5] the numbers are 9" + 16.375", which is 25.375, plus an unknown distance (about 6").  This is because the 9" & 16.375" numbers reference between station [4] and [3].  Not at station [3] which 25.375 would require.

Please tell me that the 25.375 is more like 31.375.  Otherwise I've some serious deconstruction ahead of me.
Title: Re: HELP: LEXL - plans dimension error?
Post by: thseng on September 06, 2024, 12:36:38 PM
I believe that the 16-3/4 dimension starts at the plane of the cockpit floor (bottom of stations 2 & 3).  On the plans sketch the extension line unfortunately also coincides with the dimension line for the 81-1/2 dimension, thus appearing to point to the cluster between stations 3 & 4.

Someone who has built one can verify...

Title: Re: HELP: LEXL - plans dimension error?
Post by: Brock on September 06, 2024, 01:33:08 PM
Thank you Tom, I can now see that (Arrrrr!).

I had questioned that dimension going between [3] & [4] but it looked very clear and intensonally drawn.  Based on the wrong understanding of the drawings I carefully calculated an empanage angle of 11.4 deg and bent the frame accordingly.  I'm thinking that not all is lost, except for my dislike of back-pedaling.   Remove the supports, remove station [5] tube, heat-bend to a new angle, reinstall supports in new locations.

Bite my tougue and remember to be so very grateful that I'm healthy enough to go to the shop and make silly mistakes.
Title: Re: HELP: LEXL - plans dimension error?
Post by: Kamcoman77 on September 06, 2024, 02:19:19 PM
I built mine according to the plans. Dimensions are center to center. Seems to work out OK.
Title: Followup: LEXL - plans dimension error?
Post by: Brock on September 11, 2024, 02:02:19 PM
Just following up and adding another question.
Thanks to Tom I understood that 'following the plans' and 'understanding the plans' is two different things.  In the end the fix was realatively pain free.  Shortened the supports behind station [3], removed the spot welds from station [5], heated the bend and bent down to the proper angle (station 5 height).

Now question two where I'm once again struck with a lack of understanding.
The top of Station [3], where the curved seat back tube attaches, is clearly 8" aft of where the taper bend starts.  So, IF (big if) I understand correctly, top fuselage starts it's taper 8" further aft than bottom fuselage and is wider than bottom fuselage for those 8 inches.  In short, the back of the cockpit and firewall are equal width at (design) 24".  Is this correct?
Title: Re: HELP: LEXL - plans dimension error?
Post by: Kamcoman77 on September 11, 2024, 06:09:23 PM
Page four (4) of the XL plans shows the width of Station #2 and Station #3 to be the same as each other, and the same width at the top as the bottom (24" center-to-center)
Title: Re: HELP: LEXL - plans dimension error?
Post by: Brock on September 11, 2024, 08:49:40 PM
Page four (4) of the XL plans shows the width of Station #2 and Station #3 to be the same as each other, and the same width at the top as the bottom (24" center-to-center)

Thank you.
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