Got interested in contour gauges after a recent thread.
In pipe fitting and sheetmetal there are formulas for templates n all that but it involves a lotta maff. Most of the time in the field for irregular fits we trimmed down cardboard templates or cut/ fit, cut/ fit s'more... it did work tho.
Home brew gauge methods found online were interesting tho. Spaghetti w/ ty-raps, corrugated cardboard w/ welding wire. Didn't wanna cut up my welding wire or cut the straights oughta coat hangers FTM.
Was ready to buy spaghetti at the grocery store today when I found wooden skewers at the end of the aisle, 1/8" X 9-3/4" long, $1.99/ 100. Bingo!
Cut the top flap off a cardboard shipping box in the shop, 4.5" wide. Rolled it on a smaller diameter tube then turned over and rolled again to limber it up.
Fit the cardboard around the 3" tube I was gonna test fit and trimmed the cardboard to the tube OD. Rolled the skewers out on a flat surface, pretty true except for a few. Added skewers inside the cardboard, maybe 60 of 'em. The tapered skewer ends made loading easy.
Once loaded, rolled the cardboard around the smaller tube again to keep it limber.
Used rubber bands around the cardboard to hold it on the tube. Ty-raps or velcro oughta work as well. Not too tight tho.
Tamped the skewers flat on the bench, as shown. Skewers need to be able to move to the object contour. Cardboard sleeve needs to slip on the tube as well, so again, not too tight.
First test fit on an air tank. Just push in and let the skewers adapt. Didn't mark the tank as I just painted it last week. If I was cutting in, mark the skewer gauge OD then mark again inside the first to compensate for skewer diameter. That'll ballpark it.
Contour of the tank on the gauge.
Bonus points for making one out of a spaghetti noodle box and the spaghetti, then eating it when you're done
I like this. You could make it a lot more complex, but I don't think you could make it simpler. That's a compliment.
Another test fit on the tank w/ compound curves. The weld bead was just a little bump
Shown removed.
Scoot the sleeve back and there's the contour of the tank to tube to mark. That's a pretty damn good rough in. I'd allow a little extra material tho for final fitting.
First attempt wasn't bad at all. Coulda used cardboard w/ larger opening in the corrugation for these 1/8" skewers to slip through once rounded. Asian food stores usually carry a variety of bamboo skewers in smaller diameters that could be used w/ lighter cardboard. Lighter cardboard is more flexible for smaller jobs.
No reason why this wouldn't work on square or rectangular tubing as well. For single plane surfaces like in body contour work it'd be hard to beat something like the HF gauge.
Pretty cool tho for stuff just sittin' around the house and garage.
Gonna try this on my keg foundry build.
jere
HalfDork
7/24/17 10:41 p.m.
Perfect for fish mouths! I remember seeing a store bought metallic deal like that around but this is way better because I can actually afford it
Robbie
UberDork
8/1/17 9:17 a.m.
Excellent! I was just thinking about doing this with spaghetti last night. Yours is much better!
Ingenious ,now that's using your noodles er sticks.