Author: "Fred Oldenburg" <fred_oldenburg@...> Time: Mon Feb 23, 2004 12:06 pm PST Link
Ok this may be a dumb question, but how do I determine which side the
machined head of the rivet should be on? Is there a rule of thumb?
I'm getting ready to rivet the HS-609 rear spar stiffeners to the HS-
603 rear spar channels on my RV-7A Empennage. It seems to me that the
rivets should be pointing aft - i.e. the shop heads would be on the
aft side, against the reinforcement bars and the machine heads would
be flush against the thinner spar channel material.
Is this correct? Is there a rule of thumb? After surfing other
builder's websites, I've seen it done both ways. Does it matter?
Thanks,
Fred
Fred Oldenburg
N270S (Reserved) RV-7A - Empennage
http://www.rv.oldsack.com
Author: "vbpiper" <vbpiper@...> Time: Mon Feb 23, 2004 3:03 pm PST Link
Fred,
Unless the directions specify, the machine head should go on the
thinner material to prevent deformation.
Try it both ways on a couple of pieces of scrap of different
thickneses and you will see.
Ward
--- In RV7and7A@yahoogroups.com, "Fred Oldenburg"
<fred_oldenburg@y...> wrote:
> Ok this may be a dumb question, but how do I determine which side
the
> machined head of the rivet should be on? Is there a rule of thumb?
> I'm getting ready to rivet the HS-609 rear spar stiffeners to the
HS-
> 603 rear spar channels on my RV-7A Empennage. It seems to me that
the
> rivets should be pointing aft - i.e. the shop heads would be on the
> aft side, against the reinforcement bars and the machine heads
would
> be flush against the thinner spar channel material.
>
> Is this correct? Is there a rule of thumb? After surfing other
> builder's websites, I've seen it done both ways. Does it matter?
>
> Thanks,
>
> Fred
> Fred Oldenburg
> N270S (Reserved) RV-7A - Empennage
> http://www.rv.oldsack.com
Author: "Jim Percy" <jimpercy@...> Time: Mon Feb 23, 2004 3:03 pm PST Link
In general the factory head goes on the side with thinner metal, so
your way would be the preferred way. I think the reasoning is that
the factory head is larger in diameter than the shop head, therefore
provides greater strength for the thinner metal. It's not an absoulte
rule as there are situations where it is not possible to set the
rivets this way, and you certainly wouldn't want your shop heads on
the outside where the (thin) skins are riveted to the (thicker)
longerons! Also, this would matter more in situations where the rivet
is loaded in tension. In the case of the HS reinforcement bars I
would think the primary loading on the rivets would be in shear.
I did mine with shop heads aft.
Have fun!
Jim
--- In RV7and7A@yahoogroups.com, "Fred Oldenburg"
<fred_oldenburg@y...> wrote:
> Ok this may be a dumb question, but how do I determine which side
the
> machined head of the rivet should be on? Is there a rule of thumb?
> I'm getting ready to rivet the HS-609 rear spar stiffeners to the
HS-
> 603 rear spar channels on my RV-7A Empennage. It seems to me that
the
> rivets should be pointing aft - i.e. the shop heads would be on the
> aft side, against the reinforcement bars and the machine heads
would
> be flush against the thinner spar channel material.
>
> Is this correct? Is there a rule of thumb? After surfing other
> builder's websites, I've seen it done both ways. Does it matter?
>
> Thanks,
>
> Fred
> Fred Oldenburg
> N270S (Reserved) RV-7A - Empennage
> http://www.rv.oldsack.com
Author: "Richard & Roberta Hegy" <rhegy@...> Time: Mon Feb 23, 2004 3:03 pm PST Link
My preference has been to put the shop head on the thicker material. I guess esthetics, clearance, and ease of setting are the important guidelines.
Roberta
----- Original Message -----
From: Fred Oldenburg
To: RV7and7A@yahoogroups.com
Sent: Monday, February 23, 2004 1:29 PM
Subject: [RV7Yahoo] Rivet Direction
Ok this may be a dumb question, but how do I determine which side the
machined head of the rivet should be on? Is there a rule of thumb?
I'm getting ready to rivet the HS-609 rear spar stiffeners to the HS-
603 rear spar channels on my RV-7A Empennage. It seems to me that the
rivets should be pointing aft - i.e. the shop heads would be on the
aft side, against the reinforcement bars and the machine heads would
be flush against the thinner spar channel material.
Is this correct? Is there a rule of thumb? After surfing other
builder's websites, I've seen it done both ways. Does it matter?
Thanks,
Fred
Fred Oldenburg
N270S (Reserved) RV-7A - Empennage
http://www.rv.oldsack.com
Van's Air Force - World Wide Wing
www.vansaircraft.net
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Author: "Bill Cloughley" <flybill7@...> Time: Mon Feb 23, 2004 3:03 pm PST Link
--- In RV7and7A@yahoogroups.com, "Fred Oldenburg"
<fred_oldenburg@y...> wrote:
> Ok this may be a dumb question, but how do I determine
which side the machined head of the rivet should be on?
Is there a rule of thumb? I'm getting ready to rivet the
HS-609 rear spar stiffeners to the HS-603 rear spar
channels on my RV-7A Empennage.
Actually, I think it's a great question, since I was
wondering the same thing myself yesterday when I riveted
the 609s to the 603 on my RV-7 Emp. I don't know what
the correct answer is, but I riveted with the machine
heads aft and the squeezed part forward. I did it this
way for two reasons:
1) The plans said "rivet 609 TO 603 spar"
2) The aft section of the spar is the one that will
be visible (sort of). The machine heads look a lot
better than the squeezed part!
... Bill Cloughley
RV-7 Emp
Severna Park, Maryland
Author: "microsmurfer" <microsmurfer@...> Time: Mon Feb 23, 2004 3:04 pm PST Link
I believe that's the rule of thumb (to set machine head on the
thinner piece).
I use it as a guide.
Radomir
--- In RV7and7A@yahoogroups.com, "Fred Oldenburg"
<fred_oldenburg@y...> wrote:
> Ok this may be a dumb question, but how do I determine which side
the
> machined head of the rivet should be on? Is there a rule of thumb?
> I'm getting ready to rivet the HS-609 rear spar stiffeners to the
HS-
> 603 rear spar channels on my RV-7A Empennage. It seems to me that
the
> rivets should be pointing aft - i.e. the shop heads would be on the
> aft side, against the reinforcement bars and the machine heads
would
> be flush against the thinner spar channel material.
>
> Is this correct? Is there a rule of thumb? After surfing other
> builder's websites, I've seen it done both ways. Does it matter?
>
> Thanks,
>
> Fred
> Fred Oldenburg
> N270S (Reserved) RV-7A - Empennage
> http://www.rv.oldsack.com
Author: "pepeborja925mb" <pepeborja925mb@...> Time: Mon Feb 23, 2004 4:54 pm PST Link
<SNIP> I believe that's the rule of thumb (to set machine head on the
thinner piece).<SNIP>
I looked in the MILITARY specs and my A&P book and does not list that
as a guide. The MIL Specs state that the factory head should be on
the "outside" unless noted by the specifications. It does not say
why but I assume it is easier and safer to drill out the rivets that
way (direct and clear access).
I think that rule may be more important to follow when using pulled
rivets because the pulled head may distort the thinner material.
Even with that, many airplanes built using pop rivets have the
factory head on the thcik side and the pulled end on the inside and
resting on the thin material.
I would not loose any sleep over it and follow the MIL spec (at letst
drilling out mistakes is a lot easier).
Jose.
Author: "bryan hooks" <hook3607@...> Time: Mon Feb 23, 2004 5:16 pm PST Link
I can't tell ya' much on this...but I can tell ya' from personal
experience...if you rivet two pieces together, and one of them is much
thinner than the other, the thinner one will sometimes bow/curl/deform
if the manufactured head is not on it. A good example of this was the
wing rib to wing spar rivets. Putting the manufactured head on the spar
sure makes it a lot easier to rivet, but does tend to make the edges of
the rib flange try to curl up off of the spar.
Just my 2 cents worth.
Bryan Hooks
7A, slow
Knoxville, TN
Hook3607@b...
-----Original Message-----
From: pepeborja925mb [mailto:pepeborja925mb@y...]
Sent: Monday, February 23, 2004 19:47
To: RV7and7A@yahoogroups.com
Subject: [RV7Yahoo] Re: Rivet Direction
<SNIP> I believe that's the rule of thumb (to set machine head on the
thinner piece).<SNIP>
I looked in the MILITARY specs and my A&P book and does not list that
as a guide. The MIL Specs state that the factory head should be on
the "outside" unless noted by the specifications. It does not say
why but I assume it is easier and safer to drill out the rivets that
way (direct and clear access).
I think that rule may be more important to follow when using pulled
rivets because the pulled head may distort the thinner material.
Even with that, many airplanes built using pop rivets have the
factory head on the thcik side and the pulled end on the inside and
resting on the thin material.
I would not loose any sleep over it and follow the MIL spec (at letst
drilling out mistakes is a lot easier).
Jose.
Van's Air Force - World Wide Wing
www.vansaircraft.net
Yahoo! Groups Links
Author: "Bob Collins" <bcollins@...> Time: Mon Feb 23, 2004 5:39 pm PST Link
--- In RV7and7A@yahoogroups.com, "bryan hooks" <hook3607@b...> wrote:
> wing rib to wing spar rivets. Putting the manufactured head on
the spar
> sure makes it a lot easier to rivet, but does tend to make the
edges of
> the rib flange try to curl up off of the spar.
I was thinking this very same thing. OTOH, at least with the rear
spar....the number of botched rivets by the difficulty of using the
offset rivet set in putting the manufactured head on the rib flange
vs. the spar....outweighs any curl from doing it the opposite way.
When I did my spar I kept remembering that note about this in the
Van's instructions (which I take it are no longer included in the
instructins judging by the number of people asking the question) and
I fought and wrestled -- occasionally unsuccessfully with the
contortions required. Finally after butchering a few rivets, I put
the manufactured head on the spar and the bucking bar on the
flange..and voila!
But when I realized the problem with following "the book" was when I had to drill some rivets out....a ridiculously difficult process with the factory head on the flange.
To me, it's like parking your car in a garage or parking lot in the winter. BACK IT IN, so you can get at it with another car with the jumper cables.<g>
Bob
St. Paul