From: muratlanne@gmail.com   
      
   "Bob La Londe"  wrote in message news:10o7g1e$2c2ei$1@dont-email.me...   
      
   On 3/3/2026 12:43 PM, Jim Wilkins wrote:   
   > "Jim Wilkins"  wrote in message news:10o799a$29dn0$1@dont-email.me...   
   >...   
   Remember that weldments are generally pretty brute force rough   
   applications compared to machining.  Somebody welding up a roll cage and   
   tube frame chassis isn't chasing thousandths for the main structure   
   usually.  Their main measuring tool is probably a tape measure and if   
   they are conscientious they use only one tape measure for the whole job.   
     If they are chasing thousandths they probably have a lot more   
   expensive equipment than you or I, and they are letting a machine do ALL   
   the work.   
   Bob La Londe   
   CNC Molds N Stuff   
   ---------------------------   
   Having drafted custom industrial equipment for shop fabrication and then   
   assembled it largely with hand tools I'm quite aware of specifying and   
   working to appropriate tolerances a senior engineer or machine shop foreman   
   gave me. They could shear and weld large machine frames from 12ga CRS to   
   within 1/16" or better.   
      
   The 48" tubes I mentioned were weldments that needed precisely aligned holes   
   at the ends, to align with the holes in the back of the bucket and the frame   
   on the tractor and pivot freely without binding or bending as the bucket   
   rises and lowers. I rigged up reamers on extension shafts to guide from one   
   bucket or frame hole while finishing the other.   
      
   Some parts of my sawmill are brute force, with welding shrinkage jacked out   
   "straight" by eye or hammered to a close fit afterwards but many had to be   
   machined after welding for proper alignment. The tolerance on it and the   
   gantry beam is 3/8" bolts in holes match-drilled 0.375" in steps, and most   
   of them start by hand.   
      
   At the other extreme some of my firewood sheds are made from rough logs with   
   joints fitted by chainsaw or hatchet.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)