Results 1 to 2 of 2

Thread: MEASURE TWICE, WELD TWICE Gantry Welding follow-up

  1. #1
    Join Date
    Oct 2009
    Location
    Elgin Illinois
    Posts
    658

    Default MEASURE TWICE, WELD TWICE Gantry Welding follow-up

    Well, I always hate to embarrass myself, and there are constitutional protections against self incrimination but...………….

    Last September I had removed the long aluminum extrusions which provided the structural support of my X-car. I had obtained rectangular steel tubing, and cut it to length, set it into position, aligned everything with the two y rails/angle irons of the X-car in place, by carefully measuring the diagonals of the two y rails/angle irons to make sure they were exactly equal.

    Then I had the steel tubing spot welded, then removed the two y rails/angle irons, and then had the steel tubing fully welded in place. I then re-installed the two y rails/angle irons, drilled and tapped the holes in the steel tubing
    (breaking two taps in the process)
    , then installed the bolts to hold the two y rails/angle irons.

    As a final check, I clamped a thick aluminum plate to the bottom end of the X car, set up a full sized 3 foot by 4 foot by 5 foot triangle, and checked the squareness of my rails to the bottom end of the X car..... I was mortified to find an error of 1/8 of an inch...….. I went and enlarged the mounting holes in my two rails/angle irons, and that was just not enough to be able to make up for my error.

    I then removed the two y rails/angle irons and set up the full sized 3-4-5 triangle and of course found that the X car was not square...…. So I have let it sit for a month or so,,,,, I'll have to grind out the welds, and have it all re-welded.

    My lessons are:
    1)Square up the X-car itself, and NOT measure the two y rails/angle irons...………
    2) CHECK for squareness AFTER the tack welding is done, BEFORE the final welding is done...………

    Well, on the bright side, everyone was spared from getting MORE Christmas presents made on my Bot...…..

    Chuck

    Attached Images Attached Images
    Chuck Keysor (circa 1956)
    PRT Alpha 60" x 144" (circa 2004)
    Columbo 5HP spindle
    Aspire 9.0, Rhino 5

  2. #2
    Join Date
    Dec 2005
    Location
    Pro Signs, Coal CIty IL
    Posts
    277

    Default

    Not to mention being extra careful welding, as to not warp the steel tubing.

Posting Permissions

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