« previous next »
Pages: 1 2 3 4 [5] 6 7   Go Down

Author Topic: main spar of the Fw190  (Read 3047 times)

storch

  • Guest
main spar of the Fw190
« Reply #60 on: February 04, 2006, 09:14:36 PM »
Quote
Originally posted by Bodhi
Crump,

Just an FYI...

The reason engineers decided on rivets as opposed to bolts is a simple fact of weight.

The reason we do not weld aluminum spars together is metallurgy of the base metal and flex.  Many of the metals we build with do not accept welds readily.   Aluminum welds have a tendency towards cracks when flexed, even when properly welded.
very true.  aluminum welds crack from even minimal flexing. like the amount of flexing from wind loads and expansion and contraction from daily temperature variations.  I'll be putting my third child through college from the earnings I make by having a truck at home with a portable mig welder and 150 feet of lead to the spool gun and welding balcony rails in the afternoons/early evenings/weekends.  that money goes straight to his savings account.  the best way to join aluminum is with aluminum rivets. no electrolysis between dis-similar metals and no compromising the structural integrity of the material by heating it up during welding.
Logged

Offline Crumpp

  • Parolee
  • Gold Member
  • *****
  • Posts: 3671
main spar of the Fw190
« Reply #61 on: February 04, 2006, 10:31:31 PM »
I don't see anything wrong with brazing as opposed to welding.  Much lower tempature and still offers the strength of a weld.  It was commonly used in WWII for aircraft construction AFAIK.

All the best,

Crumpp
Logged

Offline agent 009

  • Parolee
  • Nickel Member
  • ***
  • Posts: 368
main spar of the Fw190
« Reply #62 on: February 04, 2006, 10:36:04 PM »
Bolts in an overlap, if they are centered will allow for flex.
Logged

Offline Bodhi

  • Plutonium Member
  • *******
  • Posts: 8698
main spar of the Fw190
« Reply #63 on: February 04, 2006, 10:52:34 PM »
Quote
Originally posted by Crumpp
I don't see anything wrong with brazing as opposed to welding.  Much lower tempature and still offers the strength of a weld.  It was commonly used in WWII for aircraft construction AFAIK.

All the best,

Crumpp


name one example of brazing skins together, or spar components please.

The only bit I know of off hand is with some engine mount components.
« Last Edit: February 04, 2006, 10:55:22 PM by Bodhi »
Logged
I regret doing business with TD Computer Systems.

Offline Bodhi

  • Plutonium Member
  • *******
  • Posts: 8698
main spar of the Fw190
« Reply #64 on: February 04, 2006, 10:53:15 PM »
Quote
Originally posted by agent 009
Bolts in an overlap, if they are centered will allow for flex.


flex with bolts is not the issue here.  flex in welds was what we were talking about.
Logged
I regret doing business with TD Computer Systems.

Offline Crumpp

  • Parolee
  • Gold Member
  • *****
  • Posts: 3671
main spar of the Fw190
« Reply #65 on: February 04, 2006, 10:57:51 PM »
Quote
name one example of brazing skins together, or spar components please.


I can't think of any on US aircraft with the exception of tanks.  Most tanks were constructed of aluminum and brazed.

The aluminum used on US aircraft was considered inferior to that used on German Aircraft.







All the best,

Crumpp
« Last Edit: February 04, 2006, 11:07:01 PM by Crumpp »
Logged

storch

  • Guest
main spar of the Fw190
« Reply #66 on: February 05, 2006, 06:41:33 AM »
Quote
Originally posted by Bodhi
name one example of brazing skins together, or spar components please.

The only bit I know of off hand is with some engine mount components.
I was a member of the weeks air museum here in miami before hurricane andrew wiped the place out and kermit weeks moved up state to polk city florida.  I had many opportunities to be up close and personal with all of the inventory including sit in the aircraft on "family days"  those were sundays that were set aside for members to enjoy each other's company and watch all of the flyables fly and look, touch, smell the entire collection.  he had a beautifully restored P-51D done in the markings of George Preddy's "Cripes a Mighty" (the 1987 golden wrench award winner at oshkosh) the wing tips were brazed that is oxy/acetyline and aluminum rod welded.  easily the most boogered up example of welding I have ever seen.  apparently it was the way it was done prior to mig welding and quite historically accurate.  that's the only example that I know of.
Logged

Offline Bodhi

  • Plutonium Member
  • *******
  • Posts: 8698
main spar of the Fw190
« Reply #67 on: February 05, 2006, 10:43:16 AM »
I should have been specific and said structural skins Storch.

As for the fuel tanks being brazed, most examples that we have were simply stamped steel (USAAF) that were Crimped and spotwelded together.

USN tanks, like MK12's were aluminum in some cases and sometimes steel.  All versions we have were spot welded.  The Hellcat specific tanks (can not think of P/N off hand) were stamped steel, and spot welded.
Logged
I regret doing business with TD Computer Systems.

Offline agent 009

  • Parolee
  • Nickel Member
  • ***
  • Posts: 368
main spar of the Fw190
« Reply #68 on: February 05, 2006, 03:24:31 PM »
Flex period is the issue. Both welds & bolts are relevant as both were used in war.
Logged

Offline Crumpp

  • Parolee
  • Gold Member
  • *****
  • Posts: 3671
main spar of the Fw190
« Reply #69 on: February 05, 2006, 03:38:24 PM »
Quote
Flex period is the issue.


Probably why the FW-190 spar is provided with a riveted top and bottom cap to further strengthen the joints.
Logged

Offline agent 009

  • Parolee
  • Nickel Member
  • ***
  • Posts: 368
main spar of the Fw190
« Reply #70 on: February 05, 2006, 03:41:54 PM »
If someone could toss up a diagram or photo of say a Mustang wing spar, with closeup of bolts, it would help to see which is stronger. 4 bolts better than 2 etc. I still say weld is better
Logged

Offline Crumpp

  • Parolee
  • Gold Member
  • *****
  • Posts: 3671
main spar of the Fw190
« Reply #71 on: February 05, 2006, 03:45:15 PM »
Logged

Offline agent 009

  • Parolee
  • Nickel Member
  • ***
  • Posts: 368
main spar of the Fw190
« Reply #72 on: February 05, 2006, 03:54:04 PM »
Kinda hard to see. but should help somewhat.
Logged

Offline Crumpp

  • Parolee
  • Gold Member
  • *****
  • Posts: 3671
main spar of the Fw190
« Reply #73 on: February 05, 2006, 03:55:30 PM »
Be grateful someone did the work of posting it for you.
Logged

storch

  • Guest
main spar of the Fw190
« Reply #74 on: February 05, 2006, 06:13:22 PM »
Quote
Originally posted by Crumpp
Be grateful someone did the work of posting it for you.
:rofl  he probably gripes about farmers too. :aok
Logged
Pages: 1 2 3 4 [5] 6 7   Go Up
« previous next »