Re: FWIW first welding job, 2 years on

"Jim Wilkins" <muratlanne@gmail.com> writes:

"Richard Smith"  wrote in message news:m1a5d7bsh1.fsf@void.com...
>
I have contributed - this has started to happen.  I used "the bubble"
(spirit-level) on some fabrications, and found that what it cost in time
to set things off parallel at the first stage was more than made-up for
by the "ideal" time it took to fit-up and weld the rest.
Show the approach and the corrections, the owner and designer where on
the press-brake with dial-gauges, etc., and made adjustments.
ie. there is something positive going on. ...
-------------------------
Could you expand on that?
>
I found out the hard way how much welds can distort a precise
alignment, especially a weld across an inside corner. I had to jack
the sawmill ladder frame parallel (enough) and mill the shrunken gap
in a bending brake hinge assembled from surface-ground plates. The
surface welds along the sides of the plate stack didn't destroy the
0.005" fork/tongue clearance, but welding inside the fork did.
>
Do diagonal or fish mouth/tail ends (vs square) improve stress
distribution and/or reduce distortion in butt joint splice plate
welds? One end of the splice plate would be bolted, the other welded
after aligning the beams.
>
When I was building custom machinery the press brake operator and
welder compensated for distortion, the all-welded machine frames were
square to 1/32". They were mostly multiple 19" relay racks that we had
to fit the equipment panels into, so we would see any error. I knew
they marked the prints with allowances for bending and welding but
they didn't share, and the front surface welds had been ground and
filled as invisible as auto body repairs.
tia, jsw

You are well ahead of me.  i doubt i can help.

Press-brake - they have a press-brake, yes - good.
Not new when bought.  Is small "fabco.".
Seeing if corrections / calibrations needed to go in to the settings, I think.