Re: [ULF-1] New spar cap width questions

From: Member 9
Date: 2010-10-17 22:02 UTC+01:00
Message: #0256
Hello Member 62,

thank you for your comments and questions, here are my answers.

Item 1
It is correct, see also drawing no. 4 of the plan set.

Item 2
As you can see on the bottom of drawing no. 4, the kink in cap width is at
y = 380 mm. The new kink location is at y = 600 mm. The spanwise
location of rib no.2 is at y = 670 mm as it can be worked out in drwg. no. 
2.

Item 3
In full scale, the change of angle is just 0.35 degree. No worries.

Item 4
You are right! In plan no.8 ("wing loft lines") it reads: "REAR of SPAR 
including plywood skin".
This has to be replaced by: "BACK of SPAR CAP" and "END RIBS no.1 and
 no.2 start 1mm behind this SPAR CAP Ref. plane"
The nose rib markings have to be changed accordingly.

Regards,

Dieter



----- Original Message ----- 
From: <[email]>
To: <[email]>
Sent: Monday, October 11, 2010 9:00 PM
Subject: [ULF-1] New spar cap width questions


> Hi,
>
> Sorry if this has been posted before, but I didn't find it
> searching the archives ...
>
> The technical notes show a new Spar Cap
> width diagram.  It is a little difficult to get all the readings from
> such a small diagram though, so I have a few questions.
>
> 1)  I presume
> that the plan view of the width shown in the diagram is with the
> leading adge towards the top of the page.  Is this correct ?
>
> 2)  It is
> not clear how far along the spar cap changes from being 30mm wide to
> tapering down to 9mm.  It looks like it may be at rib 2.  Can anyone
> confirm this ?
>
> 3)  If 1) is correct, this means fixing the ply webbing
> to a face with two changes of angle.  Should there be a gentle radius
> at these points ?
>
> 4)  The wing rib diagrams show a common line for the
> back of the spar, but at ribs one and two there will be 1mm ply on the
> back of the spar.  Why does this not appear to be taken into account on
> the marked profiles ?  Rib one (L/E) is shown 32mm in front of the back
> of the spar (cap?), while I would expect it to be 31mm, and the rear
> section to start 1mm behind the (spar cap) line.  I hope what I mean by
> this is clear !
>
> I'm sure there are people out there who have built
> spars to this new specification, but it all seems to be pretty quiet,
> both here and on the yahoo group, when it comes to people who are
> actually building - and I know I'm going to have plenty of questions.
>
>
> Hope someone can help.
>
> Thank you.
>
> Member 62
>
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