Author: "Robert Lee Jones" <rjones22@...> Time: Thu Aug 14, 2003 1:33 pm PDT Link
--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...> wrote:
> Okay, I keep getting the same question when friends come over and
see
> how the kit is coming together - and I don't know the answer. If
> Van's can accurately punch "matched holes" for ribs, skins etc, why
> don't they punch them to final size (#30, #40 whatever) instead of
> making us drill them out? I don't ever recall seeing a reason
posted
> for the "drill to final size" step.
> Korey Smith
> 90694
Hello everybody, let me get my 2 cents in here!
My wife asked me the same question. The 51% rule and small variances
in putting it together are good answers but this is what I told my
wife; simply that running a sheet of aluminum through a machine and
punching it in manufacturing terms is a "process". In an effort to
minimize costs and final price to the builder Vans or any other
company for that matter seeks to minimize the number of processes
needed to make a part. So that's why I think the rivet holes are all
the same size.
Robert Jones
RV-9A Emp.
Author: "Andy Karmy" <andy@...> Time: Thu Aug 14, 2003 1:59 pm PDT Link
The "reason" is that punching aluminum generates stress at that hole location and it will start to crack over time. The holes need to be drilled out and cleaned up first to eliminate or at least reduce the chance of the rivet holes cracking over time.
This is the standard "Vans" answer as heard by many people over the years. That being said, some people have ignored that and simply cut down the dimple dies and moved forward with the punched holes. Seems scary to me.
In my case I did all the prep work and still managed to generate cracks. Boy am I talented!
- Andy
>--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...> wrote:
>> don't they punch them to final size (#30, #40 whatever) instead of
>> making us drill them out? I don't ever recall seeing a reason
>posted
>> for the "drill to final size" step.
Author: "Brian" <bsowell@...> Time: Thu Aug 14, 2003 2:18 pm PDT Link
Andy's right. A bit of detail that I'll add, which I've heard from
some very experienced individuals, is that the punching process makes
stress risers perpendicular to the skin's surface, and drilling them
out removes them. Any microscopic irregularities in the holes are
now parallel with the skin's surface because of the circular motion
of the drill bit, and much less likely to develop into cracks.
--- In RV-9A@yahoogroups.com, "Andy Karmy" <andy@k...> wrote:
> The "reason" is that punching aluminum generates stress at that
hole location and it will start to crack over time. The holes need to
be drilled out and cleaned up first to eliminate or at least reduce
the chance of the rivet holes cracking over time.
>
> This is the standard "Vans" answer as heard by many people over the
years. That being said, some people have ignored that and simply cut
down the dimple dies and moved forward with the punched holes. Seems
scary to me.
>
> In my case I did all the prep work and still managed to generate
cracks. Boy am I talented!
>
> - Andy
> >--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...> wrote:
>
> >> don't they punch them to final size (#30, #40 whatever) instead
of
> >> making us drill them out? I don't ever recall seeing a reason
> >posted
> >> for the "drill to final size" step.
Author: "Clay R" <clayr_55@...> Time: Thu Aug 14, 2003 2:23 pm PDT Link
If you watch those CAD/CAM machines make the skins you'll see that a
drill bit drills each and every hole. The holes aren't "punched" at
all. A spinning bit also cuts the pieces out of a larger sheet.
-Clay
--- In RV-9A@yahoogroups.com, "Brian" <bsowell@d...> wrote:
> Andy's right. A bit of detail that I'll add, which I've heard from
> some very experienced individuals, is that the punching process
makes
> stress risers perpendicular to the skin's surface, and drilling
them
> out removes them. Any microscopic irregularities in the holes are
> now parallel with the skin's surface because of the circular motion
> of the drill bit, and much less likely to develop into cracks.
> --- In RV-9A@yahoogroups.com, "Andy Karmy" <andy@k...> wrote:
> > The "reason" is that punching aluminum generates stress at that
> hole location and it will start to crack over time. The holes need
to
> be drilled out and cleaned up first to eliminate or at least reduce
> the chance of the rivet holes cracking over time.
> >
> > This is the standard "Vans" answer as heard by many people over
the
> years. That being said, some people have ignored that and simply
cut
> down the dimple dies and moved forward with the punched holes.
Seems
> scary to me.
> >
> > In my case I did all the prep work and still managed to generate
> cracks. Boy am I talented!
> >
> > - Andy
> > >--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...> wrote:
> >
> > >> don't they punch them to final size (#30, #40 whatever)
instead
> of
> > >> making us drill them out? I don't ever recall seeing a reason
> > >posted
> > >> for the "drill to final size" step.
Author: Todd Houg <thoug@...> Time: Thu Aug 14, 2003 9:52 pm PDT Link
Hello Clay,
With all due respect, I have to disagree with your about the punched vs. drilled holes. Referring back to an article in the RVator when Vans moved into their new facilities they installed a second "CNC punch press". These are used for punching all of the holes, they're not drilled. Much of the sheet stock is sheared as evidenced by the shear marks on the edges. This is readily aperent on the thicker .062 and 1/8 stock. Even on much of the thin stock you can run your hand down the edge and fell a little bump every few inches.
The story from Vans is that the punching process work hardens the edge of the hole and generates stress risers around the hole and that drilling is necessary to remove this area.
Has anyone been to the factory and seen the CNC mahinery at work? Perhaps you could chime in.
Clay, I always hate to contradict someone on the list because it harbors bad feelings, please understand there's no malicious intent, just a desire for accurate information.
BTW - Thanks for maintaining the photo journal of completed RV-9's!
Todd Houg
-----Original Message-----
From: Clay R
Sent: Thursday, August 14, 2003 4:23 PM
To: RV-9A@yahoogroups.com
Subject: [RV-9A] Re: Pre-punched kit question
If you watch those CAD/CAM machines make the skins you'll see that a
drill bit drills each and every hole. The holes aren't "punched" at
all. A spinning bit also cuts the pieces out of a larger sheet.
-Clay
--- In RV-9A@yahoogroups.com, "Brian" <bsowell@d...> wrote:
> Andy's right. A bit of detail that I'll add, which I've heard from
> some very experienced individuals, is that the punching process
makes
> stress risers perpendicular to the skin's surface, and drilling
them
> out removes them. Any microscopic irregularities in the holes are
> now parallel with the skin's surface because of the circular motion
> of the drill bit, and much less likely to develop into cracks.
> --- In RV-9A@yahoogroups.com, "Andy Karmy" <andy@k...> wrote:
> > The "reason" is that punching aluminum generates stress at that
> hole location and it will start to crack over time. The holes need
to
> be drilled out and cleaned up first to eliminate or at least reduce
> the chance of the rivet holes cracking over time.
> >
> > This is the standard "Vans" answer as heard by many people over
the
> years. That being said, some people have ignored that and simply
cut
> down the dimple dies and moved forward with the punched holes.
Seems
> scary to me.
> >
> > In my case I did all the prep work and still managed to generate
> cracks. Boy am I talented!
> >
> > - Andy
> > >--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...> wrote:
> >
> > >> don't they punch them to final size (#30, #40 whatever)
instead
> of
> > >> making us drill them out? I don't ever recall seeing a reason
> > >posted
> > >> for the "drill to final size" step.
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Author: "Greg & Cindy" <gtanner@...> Time: Thu Aug 14, 2003 10:23 pm PDT Link
Been there--seen it--watched it work--looked at product after it came out.
It punches the holes--no drill(s) involved. Even small parts are punched out
of sheets of aluminum by punching holes all around the perimeter.
Greg Tanner
-----Original Message-----
From: Todd Houg [mailto:thoug@a...]
Sent: Thursday, August 14, 2003 9:02 PM
To: 'RV-9A@yahoogroups.com'
Subject: RE: [RV-9A] Re: Pre-punched kit question
Hello Clay,
With all due respect, I have to disagree with your about the punched vs.
drilled holes. Referring back to an article in the RVator when Vans moved
into their new facilities they installed a second "CNC punch press". These
are used for punching all of the holes, they're not drilled. Much of the
sheet stock is sheared as evidenced by the shear marks on the edges. This is
readily aperent on the thicker .062 and 1/8 stock. Even on much of the thin
stock you can run your hand down the edge and fell a little bump every few
inches.
The story from Vans is that the punching process work hardens the edge of
the hole and generates stress risers around the hole and that drilling is
necessary to remove this area.
Has anyone been to the factory and seen the CNC mahinery at work? Perhaps
you could chime in.
Clay, I always hate to contradict someone on the list because it harbors bad
feelings, please understand there's no malicious intent, just a desire for
accurate information.
BTW - Thanks for maintaining the photo journal of completed RV-9's!
Todd Houg
-----Original Message-----
From: Clay R
Sent: Thursday, August 14, 2003 4:23 PM
To: RV-9A@yahoogroups.com
Subject: [RV-9A] Re: Pre-punched kit question
If you watch those CAD/CAM machines make the skins you'll see that a
drill bit drills each and every hole. The holes aren't "punched" at
all. A spinning bit also cuts the pieces out of a larger sheet.
-Clay
--- In RV-9A@yahoogroups.com, "Brian" <bsowell@d...> wrote:
> Andy's right. A bit of detail that I'll add, which I've heard from
> some very experienced individuals, is that the punching process
makes
> stress risers perpendicular to the skin's surface, and drilling
them
> out removes them. Any microscopic irregularities in the holes are
> now parallel with the skin's surface because of the circular motion
> of the drill bit, and much less likely to develop into cracks.
> --- In RV-9A@yahoogroups.com, "Andy Karmy" <andy@k...> wrote:
> > The "reason" is that punching aluminum generates stress at that
> hole location and it will start to crack over time. The holes need
to
> be drilled out and cleaned up first to eliminate or at least reduce
> the chance of the rivet holes cracking over time.
> >
> > This is the standard "Vans" answer as heard by many people over
the
> years. That being said, some people have ignored that and simply
cut
> down the dimple dies and moved forward with the punched holes.
Seems
> scary to me.
> >
> > In my case I did all the prep work and still managed to generate
> cracks. Boy am I talented!
> >
> > - Andy
> > >--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...> wrote:
> >
> > >> don't they punch them to final size (#30, #40 whatever)
instead
> of
> > >> making us drill them out? I don't ever recall seeing a reason
> > >posted
> > >> for the "drill to final size" step.
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Author: "Clay R" <clayr_55@...> Time: Fri Aug 15, 2003 6:42 am PDT Link
Well, I stood next to the machines watching parts being made at Vans
and the person explained it that way to me.... so maybe they were
wrong?
Possibly some parts are made this way and others are in fact punched?
Maybe a call to Vans to get the real scoop is in order?
--Clay
--- In RV-9A@yahoogroups.com, Todd Houg <thoug@a...> wrote:
> Hello Clay,
>
> With all due respect, I have to disagree with your about the
punched vs. drilled holes. Referring back to an article in the RVator
when Vans moved into their new facilities they installed a
second "CNC punch press". These are used for punching all of the
holes, they're not drilled. Much of the sheet stock is sheared as
evidenced by the shear marks on the edges. This is readily aperent on
the thicker .062 and 1/8 stock. Even on much of the thin stock you
can run your hand down the edge and fell a little bump every few
inches.
> The story from Vans is that the punching process work hardens the
edge of the hole and generates stress risers around the hole and that
drilling is necessary to remove this area.
>
> Has anyone been to the factory and seen the CNC mahinery at work?
Perhaps you could chime in.
>
> Clay, I always hate to contradict someone on the list because it
harbors bad feelings, please understand there's no malicious intent,
just a desire for accurate information.
>
> BTW - Thanks for maintaining the photo journal of completed RV-9's!
>
> Todd Houg
> -----Original Message-----
> From: Clay R
> Sent: Thursday, August 14, 2003 4:23 PM
> To: RV-9A@yahoogroups.com
> Subject: [RV-9A] Re: Pre-punched kit question
>
> If you watch those CAD/CAM machines make the skins you'll see that
a
> drill bit drills each and every hole. The holes aren't "punched"
at
> all. A spinning bit also cuts the pieces out of a larger sheet.
>
> -Clay
>
> --- In RV-9A@yahoogroups.com, "Brian" <bsowell@d...> wrote:
> > Andy's right. A bit of detail that I'll add, which I've heard
from
> > some very experienced individuals, is that the punching process
> makes
> > stress risers perpendicular to the skin's surface, and drilling
> them
> > out removes them. Any microscopic irregularities in the holes
are
> > now parallel with the skin's surface because of the circular
motion
> > of the drill bit, and much less likely to develop into cracks.
> > --- In RV-9A@yahoogroups.com, "Andy Karmy" <andy@k...> wrote:
> > > The "reason" is that punching aluminum generates stress at that
> > hole location and it will start to crack over time. The holes
need
> to
> > be drilled out and cleaned up first to eliminate or at least
reduce
> > the chance of the rivet holes cracking over time.
> > >
> > > This is the standard "Vans" answer as heard by many people over
> the
> > years. That being said, some people have ignored that and simply
> cut
> > down the dimple dies and moved forward with the punched holes.
> Seems
> > scary to me.
> > >
> > > In my case I did all the prep work and still managed to
generate
> > cracks. Boy am I talented!
> > >
> > > - Andy
> > > >--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...>
wrote:
> > >
> > > >> don't they punch them to final size (#30, #40 whatever)
> instead
> > of
> > > >> making us drill them out? I don't ever recall seeing a
reason
> > > >posted
> > > >> for the "drill to final size" step.
> To unsubscribe from this group, send an email to:
> RV-9A-unsubscribe@egroups.com
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
> [Non-text portions of this message have been removed]
Author: Todd Houg <thoug@...> Time: Fri Aug 15, 2003 9:15 pm PDT Link
I seem to have been put on the "bouncing" status according to yahoo groups, so I am only receiving some of the posts. Not sure if it's related to the power outage or what.
Anyway, I did see Clay's response in the yahoo website and found it interesting that he was told they were being drilled. Everything I've read about their process has always referred to punching, but I guess Van's would be the people to ask. There are some pieces of Al angle in the fuse that appeared to be pre-drilled instead of punched maybe they drill the angle/bar stock and punch the sheets?
Todd Houg
-----Original Message-----
From: Greg & Cindy
Sent: Friday, August 15, 2003 12:25 AM
To: RV-9A@yahoogroups.com
Subject: RE: [RV-9A] Re: Pre-punched kit question
Been there--seen it--watched it work--looked at product after it came out.
It punches the holes--no drill(s) involved. Even small parts are punched out
of sheets of aluminum by punching holes all around the perimeter.
Greg Tanner
-----Original Message-----
From: Todd Houg [mailto:thoug@a...]
Sent: Thursday, August 14, 2003 9:02 PM
To: 'RV-9A@yahoogroups.com'
Subject: RE: [RV-9A] Re: Pre-punched kit question
Hello Clay,
With all due respect, I have to disagree with your about the punched vs.
drilled holes. Referring back to an article in the RVator when Vans moved
into their new facilities they installed a second "CNC punch press". These
are used for punching all of the holes, they're not drilled. Much of the
sheet stock is sheared as evidenced by the shear marks on the edges. This is
readily aperent on the thicker .062 and 1/8 stock. Even on much of the thin
stock you can run your hand down the edge and fell a little bump every few
inches.
The story from Vans is that the punching process work hardens the edge of
the hole and generates stress risers around the hole and that drilling is
necessary to remove this area.
Has anyone been to the factory and seen the CNC mahinery at work? Perhaps
you could chime in.
Clay, I always hate to contradict someone on the list because it harbors bad
feelings, please understand there's no malicious intent, just a desire for
accurate information.
BTW - Thanks for maintaining the photo journal of completed RV-9's!
Todd Houg
-----Original Message-----
From: Clay R
Sent: Thursday, August 14, 2003 4:23 PM
To: RV-9A@yahoogroups.com
Subject: [RV-9A] Re: Pre-punched kit question
If you watch those CAD/CAM machines make the skins you'll see that a
drill bit drills each and every hole. The holes aren't "punched" at
all. A spinning bit also cuts the pieces out of a larger sheet.
-Clay
--- In RV-9A@yahoogroups.com, "Brian" <bsowell@d...> wrote:
> Andy's right. A bit of detail that I'll add, which I've heard from
> some very experienced individuals, is that the punching process
makes
> stress risers perpendicular to the skin's surface, and drilling
them
> out removes them. Any microscopic irregularities in the holes are
> now parallel with the skin's surface because of the circular motion
> of the drill bit, and much less likely to develop into cracks.
> --- In RV-9A@yahoogroups.com, "Andy Karmy" <andy@k...> wrote:
> > The "reason" is that punching aluminum generates stress at that
> hole location and it will start to crack over time. The holes need
to
> be drilled out and cleaned up first to eliminate or at least reduce
> the chance of the rivet holes cracking over time.
> >
> > This is the standard "Vans" answer as heard by many people over
the
> years. That being said, some people have ignored that and simply
cut
> down the dimple dies and moved forward with the punched holes.
Seems
> scary to me.
> >
> > In my case I did all the prep work and still managed to generate
> cracks. Boy am I talented!
> >
> > - Andy
> > >--- In RV-9A@yahoogroups.com, "cherokee6fl" <jksmith@e...> wrote:
> >
> > >> don't they punch them to final size (#30, #40 whatever)
instead
> of
> > >> making us drill them out? I don't ever recall seeing a reason
> > >posted
> > >> for the "drill to final size" step.
To unsubscribe from this group, send an email to:
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[Non-text portions of this message have been removed]
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Author: "Clay R" <clayr_55@...> Time: Sun Aug 17, 2003 1:07 pm PDT Link
I found the website for the piece of equipment that Vans uses:
(Trumatic 200)
http://www.trumpf.com/
Sure enough, this IS a punching tool.. So either I misunderstood, or
the person telling me wasn't sure, or a little of both. Could be
that the thicker parts are drilled on a different machine... I don't
know.
This tool "cuts" pieces of aluminum by punching lots of connecting
holes around the perimeter which explains the jagged edges on the
thicker pieces.
They must shovel aluminum bits out of that machine by the bucketload!
Thanks everyone for setting me straight!
Clay
--- In RV-9A@yahoogroups.com, Todd Houg <thoug@a...> wrote:
> I seem to have been put on the "bouncing" status according to
yahoo groups, so I am only receiving some of the posts. Not sure if
it's related to the power outage or what.
>
> Anyway, I did see Clay's response in the yahoo website and found
it interesting that he was told they were being drilled. Everything
I've read about their process has always referred to punching, but I
guess Van's would be the people to ask. There are some pieces of Al
angle in the fuse that appeared to be pre-drilled instead of punched
maybe they drill the angle/bar stock and punch the sheets?
>
> Todd Houg