Portable jig for field drilling a through hole in a 3" tube

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Here's a portable jig I made to accurately drill a through-hole at a precise location on a 3" tube for a field project at work. It's purpose is to center a perpendicular 10mm drill hole on the tube, while ensuring the hole is a set distance from the end of the tube. I notched the cradle plate with a grinder and then folded it. I then welded the seams once I had it folded to symetrical angles.The cross bridge acts as a drill bit guide and a stop. The 1" C channel has 2" angle welded to the channel's open side so that my drill bit would be restrained at the top and bottom for perpendicularity.  The angle also acts as a stop so that the hole is drilled 25mm from the end of the tube.This is my first project with thick plate using the TIG process. Attached Images
Reply:Very nice! "Every choice you make will effect at least one other person"
Reply:That should work, nice job.Now use it a few times, toss it is some deep dark hole in the back of the shop, then find it a year or so later and wonder what the heII it was for....At least that is what happens to me. If you cant fix it with a hammer, it must be an electrical problem."Boy, everyone starts with a full bag of luck and an empty bag of experience. The trick is to fill the bag of experience before the bag of luck is empty."-Grandad circa 1990ish
Reply:I first thought, "How do you drill a 3" hole with that jig?", then I reread and got 10mm hole in 3" pipe. lol I already have a use for this jig. Good ideaMillermatic 200Hobart Handler 120Victor O/A & Ramco BandsawLincoln 225 ACSnapOn AD HoodMiller XMT304/22AHypertherm Powermax 1650 G3Lincoln Idealarc DC600 w/Extreme 12 VSMiller Digital Elite "Joker"