Page 1 of 2 12 LastLast
Results 1 to 10 of 11

Thread: Trunnion welding question...

  1. #1
    Veteran KidKalash66's Avatar
    Join Date
    Jun 2008
    Location
    AL
    Posts
    350
    Rep Power
    79

    Trunnion welding question...

    I'm aware that the preferred method of welding a trunnion into a rec. is to drill holes in the rec. in 4 specified places,and Tig weld into the hole to attach,such as Hk does at the factory. HOWEVER,I've noticed 2 guns that were done differently at some shops lately. One was a stamped early Century,that when the h.g. was removed I noticed a nearly full circle weld around the FRONT of the trunnion to the edge of the receiver,looked solid and neat,and NO spot welds around the usual areas,just the line along the bottom. Also noted a Hesse gun with this same weld procedure,though the builder had cut 3 1" slots out of the front trunnion ring and welded down into those cuts,also looked neat and the gun had been fired extensively w/out ill effects,according to the owner,FWIW. No spot welds around the front ring on the Hessie either,just the usual side scallops welded in as customary. So what's up with this option? Seems the traditional weld-in-the-holes factory method would be simpler. Any foreseen detrimental effects for a build like this? Perhaps the trunnion not stable enough (receiver flex) for accuracy? Note the 3 short welds around this Hesse trunnion... g3 010.jpg
    Last edited by KidKalash66; 06-25-2008 at 06:24 PM.
    Buy the ticket,take the ride..... Dr.Hunter S.Thompson

  2. #2
    Senior Veteran turbothis's Avatar
    Join Date
    Mar 2007
    Location
    southern oregon
    Posts
    4,005
    Rep Power
    124
    i would think the front ring weld would be the best. maybe there is something to it....
    have cnc mills, will work for food.
    http://www.gunsnorthwest.com/

  3. #3
    Veteran KidKalash66's Avatar
    Join Date
    Jun 2008
    Location
    AL
    Posts
    350
    Rep Power
    79
    BUT,Hk did it the other way....hard to fight that logic I suppose.Until I saw Gunplumber's pictorial on how to do it the traditional way(wire weld in the holes),I always assumed they were spot welded by one of those auto-plant type robotic welders at the Hk facility,for speed and efficiency purposes...
    Buy the ticket,take the ride..... Dr.Hunter S.Thompson

  4. #4
    Senior Veteran bladeworks123's Avatar
    Join Date
    Jan 2008
    Location
    Colorado - Out West
    Posts
    6,437
    Rep Power
    245
    Quote Originally Posted by KidKalash66 View Post
    BUT,Hk did it the other way....hard to fight that logic I suppose.Until I saw Gunplumber's pictorial on how to do it the traditional way(wire weld in the holes),I always assumed they were spot welded by one of those auto-plant type robotic welders at the Hk facility,for speed and efficiency purposes...

    Where exactly did you find "Gunplumber's pictorial) I would like to see that.

    Thanks
    BATTLEMENT ARMS
    www.battlementarms.com

  5. #5
    Veteran KidKalash66's Avatar
    Join Date
    Jun 2008
    Location
    AL
    Posts
    350
    Rep Power
    79
    Last edited by KidKalash66; 06-25-2008 at 08:46 PM.
    Buy the ticket,take the ride..... Dr.Hunter S.Thompson

  6. #6
    rustypirate
    Guest
    The "ring around the trunion" method of welding was done by Hesse and Century because it was time and effort expedient, not because it was better. both the Century and HK methods for welding the trunion was to use a spot welder with a custom jig.

    Because we do not have access to such a jig, the closest way to replicate the proper welding technique is to drill holes in the receiver and plug weld the trunion and fill the holes.

    You will also find that the Century and Hesse receivers were not drilled for the barrel pin access either, it was just plane lazyness.

  7. #7
    Veteran Deadheadmatt's Avatar
    Join Date
    Mar 2007
    Location
    Boise, ID
    Posts
    380
    Rep Power
    93
    HK might have gone the plug welding route because they were considering the possibility that the barrell and trunnion may have to be replaced in the future? It would be easier to grind out a couple of spot welds instead of trying to remove the weld line around the entire end of the trunnion.

    I'm just speculating here...

  8. #8
    Veteran vista461's Avatar
    Join Date
    Mar 2007
    Location
    S.E. WI
    Posts
    595
    Rep Power
    95
    Wouldn't it be more stable with the welds on the side rather than just the front? Making it more "one" with the receiver?
    Jamie

  9. #9
    Veteran KidKalash66's Avatar
    Join Date
    Jun 2008
    Location
    AL
    Posts
    350
    Rep Power
    79
    My speculation is simply the "big factory" reasoning by Hk and Santa Barbara(cetme) that they could trog along faster in assembly line fashion using a spot welder (big expensive device,even in the 50's) to attach the trunnion. If you do the math,same amount of material is attached either way,IMHO.Of course I haven't seen a machinists mathematical equation that would trump spot welds only a 1/4" farther back from the edge than the nearly 360 deg edge weld itself,hopefully there is such info published somwhere,I just haven't found it yet. It would be cool to do a back to back test of both methods by a competent builder,using the same quality parts,then test for accuracy and longevity.
    Buy the ticket,take the ride..... Dr.Hunter S.Thompson

  10. #10
    Veteran dirty8's Avatar
    Join Date
    Mar 2007
    Posts
    61
    Rep Power
    92
    I personally like the spot weld technique over welding the circumfrence. If the trunion ever needed to be replaced, removing the spot welds would be easier.

Similar Threads

  1. welding
    By jets in forum Build it Yourself/Gunsmithing
    Replies: 4
    Last Post: 08-07-2009, 01:28 PM
  2. WTT my amd front trunnion for yugo front trunnion
    By sava6e in forum Want to Buy
    Replies: 0
    Last Post: 06-24-2009, 06:23 PM
  3. Replies: 6
    Last Post: 04-25-2008, 02:24 PM
  4. barrel and trunnion question
    By trenches in forum Cetme/HK
    Replies: 7
    Last Post: 02-17-2008, 10:27 AM
  5. welding trunnion to Cetme receiver
    By trenches in forum Build it Yourself/Gunsmithing
    Replies: 2
    Last Post: 02-13-2008, 07:59 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •