Drilling holes in steel tubing

On Fri, 30 Sep 2005 21:24:47 -0700, Smitty Two
wrote:

In article .com,
"wright1902glider" wrote:

If you're paralleling the tubes for six inches or more, and you filled
the notches between them top and bottom with a fillet of serious
industrial epoxy, (not the five minute stuff) I'd think you'd be able to
support more of a cantilevered load before the glue sheared, than you
would before the tubing folded at the bolt holes.

From a strenght issue, I agree; most adhesives I've worked with will
fail from the concentrated peel forces in an application like this.
What he wants to do is taper a wedge, probably of wood, over a few
inches so the load is unifirmly imposed. No, I cannot do a sketch.

(EMT isn't very
strong, and you're going to need a 0.187" hole for a #10 bolt.)

I want to see how hard he has to drive to get a 0.190" fastener (#10)
through a 0.187" hole ...

In reality, I agree with you. Most #10 are specifically on the low
side of tolerance so they can fit the 3/16" spec, and most drills
drill oversize.

Anyway, I can see you like the bolts. You could make your own clamping
fixture, a combination of the V-block idea and the two by four idea. If
you have a table saw, you could cut stepped grooves in two 6 or 8 inch
long wood blocks. The inner step has a width and depth of 1/2". The
outer step has a width of 1" and a depth of 1/2." Drill some holes for
drill bushings, available at the industrial hardware store, press them
in, clamp the two halves around the three tubes, and drill.

And leave the v-grooved blocks installed, extending past the fasteners
in the loaded direction.

Have you tried JB Weld. Tough as hell and sticks like glue.

Big John
`````````````````````````````````````````````````` ``````````````````````````````````````````````

On 30 Sep 2005 19:40:40 -0700, "wright1902glider"
wrote:

Has anyone seen v-blocks for sale at Lowe's or HD?

Epoxy doesn't offer enough strength. I'm attempting to recreate a
test-rig that the Wrights used before building the wind tunnel. It
consists of a regular bicycle with third wheel mounted horizontally out
in front of the handlebars. Attached vertically to either side of the
horizontal wheel are model airfoils or flat plates.

The theory was that using trigonometry, the wrights could evaluate
various airfiol sections by measuring the angle of deflection off
center, one airfoil vs. another.

Of course, it wasn't acurate enough for scientific purposes, hence the
wind tunnel, but it'll be fun to demonstrate at airshows.