Re: Outdoor Welding

"Bob La Londe"  wrote in message news:103kkic$3nnjj$1@dont-email.me...
I've made a few parts to scribe lines and center punches.  I made a
point of it after my son gave me an optical center punch set for
Christmas one year.  I even have a couple height gages with carbide
scribes for helping with layout, although one usually only gets used to
measure tool heights to be entered into a CNC machine's tool table.  Its
pretty scary when I bring that carbide scribe down on top of a 0.026"
ball nose end mill to measure the height.
Bob La Londe
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I haven't seen much if any need for manual layout when making new parts to drawings, it's for modifying existing parts and castings that lack drawings and reference surfaces. I use it to mount electrical components in plastic cases that compress when held firmly enough in the milling vise and can't be repeatedly zeroed.
For instance I repaired a pivot hole in a control handle that had become egg-shaped almost to uselessness by locating the original center by running a plug against the unworn side, boring the hole larger and pressing in a bushing. This helped repair a $100 Toro 724 snowblower with all repairable metal parts and good balance that doesn't hurt my back to maneuver. I can't usually repair broken plastic, I have to redesign the part in metal. A new plastic part could fail the same way when it becomes brittle in the cold.
Another way to mark a hole center is to press in a wooden plug and into that a square of sheet metal with its corners turned down. If other centers are known they can be used to scribe the missing center on the sheet metal. Punch, center and bore it on the mill or lathe. Taps ground between centers are useful for locating tapped through holes, pointed setscrews for blind ones.