Author: manlosangeles@... Time: Sat Dec 1, 2001 4:01 pm PST Link
I've seen some RVs without any "waviness" on the wing skins as the
skins drape between ribs.
On other RVs, there is absolutely no waviness and if you can't see
the rivets you have no idea where the ribs are located - absolutely
flat. (specifically, a local RV8)
Why the difference? Do some RVs use thinner gauge aluminum for the
wing skins that causes the "waviness"? If so, does the 7A use the
thinner or thicker wing skins?...
Author: "Andy Russell" <russella111@...> Time: Sat Dec 1, 2001 4:38 pm PST Link
The fun begins - now you are really getting into the art of building planes...it has to do with the method and pattern of riveting as well as the skin temp at riveting...
----- Original Message -----
From: manlosangeles@y... (mailto:manlosangeles@y...)
To: RV7and7A@yahoogroups.com (mailto:rv7and7a@yahoogroups.com)
Sent: Saturday, December 01, 2001 5:01 PM
Subject: [RV7and7A] Skin waviness on some RVs but not others
I've seen some RVs without any "waviness" on the wing skins as the
skins drape between ribs.
On other RVs, there is absolutely no waviness and if you can't see
the rivets you have no idea where the ribs are located - absolutely
flat. (specifically, a local RV8)
Why the difference? Do some RVs use thinner gauge aluminum for the
wing skins that causes the "waviness"? If so, does the 7A use the
thinner or thicker wing skins?...
Van's Air Force- World Wide Wing
www.vansaircraft.net
Your useof Yahoo! Groups is subject to the Yahoo! Terms of Service (http://docs.yahoo.com/info/terms/).
(end of quote)
Author: GTCJ68@... Time: Mon Dec 3, 2001 8:02 am PST Link
Some folks will heat the skins with a heat gun just prior to riveting. This expands them slightly. So, after they've been riveted on and cool (shrink) you can get a real tight fit. This helps to alleviate the waviness.
Mitch
Author: bedrock@... Time: Mon Dec 3, 2001 8:57 am PST Link
There is a good write up on this in 21 years of RVaitor. Too much for
me to repeat here.
Neil
--- In RV7and7A@y..., "Hugh Tyler (SBI-Chico)" <hugh@b...> wrote:
> Thanks Mitch,
>
> I am still fuzzy on the process. Do you heat the skins prior to
drilling as
> well or only during riveting (after drilling and dimpling)? Can you
reheat
> the skins while in the middle of riveting (it seems like you would
have
> to)? Thanks again.
>
> Hugh
>
> -----Original Message-----
> From: GTCJ68@a... [mailto:GTCJ68@a...]
> Sent: Monday, December 03, 2001 8:02 AM
> To: RV7and7A@y...
> Subject: Re: [RV7and7A] Skin waviness on some RVs but not others
> Some folks will heat the skins with a heat gun just prior to
riveting. This
> expands them slightly. So, after they've been riveted on and cool
(shrink)
> you can get a real tight fit. This helps to alleviate the
waviness.
>
> Mitch
>
> Van's Air Force - World Wide Wing
> www.vansaircraft.net
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> <http://docs.yahoo.com/info/terms/> Service.
Author: manlosangeles@... Time: Mon Dec 3, 2001 2:39 pm PST Link
interesting, but if you've already drilled the holes, why would
expansion/shrinkage have any net effect on the finished product?
i could understand if waviness is reduced maybe if you used a jig to
locate and drill holes, since the skins would be vertical and so they
wouldn't "drape" over the ribs.
--- In RV7and7A@y..., GTCJ68@a... wrote:
> Some folks will heat the skins with a heat gun just prior to
riveting. This
> expands them slightly. So, after they've been riveted on and cool
(shrink)
> you can get a real tight fit. This helps to alleviate the waviness.
>
> Mitch
Author: manlosangeles@... Time: Mon Dec 3, 2001 2:40 pm PST Link
interesting, but if you've already drilled the holes, why would
expansion/shrinkage have any net effect on the finished product?
i could understand if waviness is reduced maybe if you used a jig to
locate and drill holes, since the skins would be vertical and so they
wouldn't "drape" over the ribs.
--- In RV7and7A@y..., GTCJ68@a... wrote:
> Some folks will heat the skins with a heat gun just prior to
riveting. This
> expands them slightly. So, after they've been riveted on and cool
(shrink)
> you can get a real tight fit. This helps to alleviate the waviness.
>
> Mitch
Author: manlosangeles@... Time: Mon Dec 3, 2001 2:44 pm PST Link
oh pleeeease? just some main points? i just ordered 7A preview
plans and this year's RViator... have mercy!
maybe waviness is also simply a function of wing temperature when
viewed (and skin thickness)? this would explain why the RV8 i've
seen that has no waviness is in a hanger (cool wings) and the "wavy"
wings i've seen are air-to-air pictures in the sun (warm wings??).
--- In RV7and7A@y..., bedrock@t... wrote:
> There is a good write up on this in 21 years of RVaitor. Too much
for
> me to repeat here.
>
> Neil
>
> --- In RV7and7A@y..., "Hugh Tyler (SBI-Chico)" <hugh@b...> wrote:
> > Thanks Mitch,
> >
> > I am still fuzzy on the process. Do you heat the skins prior to
> drilling as
> > well or only during riveting (after drilling and dimpling)? Can
you
> reheat
> > the skins while in the middle of riveting (it seems like you
would
> have
> > to)? Thanks again.
> >
> > Hugh
> >
> > -----Original Message-----
> > From: GTCJ68@a... [mailto:GTCJ68@a...]
> > Sent: Monday, December 03, 2001 8:02 AM
> > To: RV7and7A@y...
> > Subject: Re: [RV7and7A] Skin waviness on some RVs but not others
> > Some folks will heat the skins with a heat gun just prior to
> riveting. This
> > expands them slightly. So, after they've been riveted on and
cool
> (shrink)
> > you can get a real tight fit. This helps to alleviate the
> waviness.
> >
> > Mitch
> >
> > Van's Air Force - World Wide Wing
> > www.vansaircraft.net
> > Your use of Yahoo! Groups is subject to the Yahoo! Terms of
> > <http://docs.yahoo.com/info/terms/> Service.
Author: GTCJ68@... Time: Tue Dec 4, 2001 3:49 am PST Link
Hugh,
First, I have never done this skin heating process. I don't think it is really worth the effort. My information comes from a freind and RV-4 builder who has. No, you don't need to heat the skins while drilling. And you must continually heat as the riveting process proceeds. The gain in skin tightness, in my opinion is minimal if any at all. Skin waviness due to heat is really a function of the current ambient temperature. On cool days the skins on my RV-6 looked smooth. In July... surf's up!
Mitch