A Notch In Time, page 4 of 4

Hole Saw Image Any idea how long it would take to notch a tube like this on a bench grinder? This one will fit right away, too. A punch-type notcher is even faster.

JD Squared's Barnard says they did the same testing, but came up with different results. "We built them both ways, with needle bearings and bronze bushings, and found the brass bushing was definitely not the way to go. We hear from customers that the bushing style doesn't have the tight tolerance they want. Any time you get wobble in the shaft, your cutter won't hold true and you get no cutter life at all. So we went to the needle bearings instead of the brass bushings. Then we sealed them top and bottom. I'd rather have one that if the needle bearings go bad in two years, you just knock them out and put a set of needle bearings in. You get a brand new machine."

These days it takes a lot less money and a lot less time to properly notch a tube for welding. Now more than ever, there's no excuse for a poor fit. Whether you use a punch-style notcher from Williams or a hole saw notcher from someone else, fabricating can be fun. But remember: using notchers without safety glasses is just as dangerous as welding without a helmet. As always, use your tools properly.

Summary, by Dave Williams of Williams Lowbuck Tools

Well, they didn't talk too much about our Lowbuck "punch type" notcher 'cause they spent so much time talking about what was wrong, or could go wrong, or had to be replaced on hole saw notchers. All they said about ours is you bolt it down, use it, and it works. With our notcher they didn't have much to say about bushings, bearings, drill presses, cutting oil, or worn out hole saws because our notcher simply doesn't have any of those problems. The more worn-in it gets, the better it works. You don't need a drill press or a big, slow-speed 1/2-inch drill to use our notcher. And you know as soon as you bolt that other notcher to your drill press, you're going to need to drill a bracket or something. Our notcher requires no messy oil cleanup. And our cutters don't wear out.

One thing I'd like to point out is the two different notches produced by the two very different methods. You decide which is best. As strange as it sounds, the problem with the hole saw method is it produces too good of a fit. We all know that a good weld is one that has been "V'd" out to a slight gap that is filled in by weld. If the tube is cut to a perfect, tight fit as shown in the photos and my illustrations, you get an overlap weld without proper penetration. The female cutter (the "saddle" referred to in the article) of the Lowbuck notcher is set at an angle. That produces the proper V-gap in the notch for welding.

One last thought. I think hole saws are scary even when they're used the way they're designed to cut on a 360-degree surface. But hole saws were never made to cut half holes. Hole saw notchers use a potentially dangerous tool in a way it wasn't intended. Why someone would choose one when the alternative is safer, faster, cleaner, much easier to use, and won't break or wear out, I don't understand.

thank you for your time,

Dave

Hole Saw Fit - too tight for welding.
I would bet if you were building an airplane with tight fits like this, the F.A.A. inspector would want them "V'd" out before final welding. Also notice angle fits in photos, the problem is even worse.

Punch Type Fit

V-gap produced by reverse-angle cut of Lowbuck notcher. Also, there is gap at the ends produced by cut-off saw when cutting the tubing to length.