Drilling holes in steel tubing

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.

In article .com,
"wright1902glider" wrote:



Epoxy doesn't offer enough strength.

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. (EMT isn't very
strong, and you're going to need a 0.187" hole for a #10 bolt.) But
that's just a feeling. I was the guy who built the weakest cardboard
bridge in high school physics, so I'm probably wrong.

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.

The best (strongest) epoxy is Belzona 1111 also refered to as Belzona
Super Metal.
Super Metal is machineable, no VOC's, no solvents, does not rot, does
not rust, does not shrink, or does not corrode. It is compatable with
all metals.
The same can not be said of Devcon, JB Weld, and most other epoxies on
the market. Yes many claim to be as good as Belzona but experience and
research has proven time and again they do not produce results as good
as the Belzona product. Belzona is may be more expensive but, if
results are important, is actually less expensive.
www.belzona.com

In article .com,
"Clay" wrote:

The best (strongest) epoxy is Belzona 1111 also refered to as Belzona
Super Metal.
Super Metal is machineable, no VOC's, no solvents, does not rot, does
not rust, does not shrink, or does not corrode. It is compatable with
all metals.
The same can not be said of Devcon, JB Weld, and most other epoxies on
the market. Yes many claim to be as good as Belzona but experience and
research has proven time and again they do not produce results as good
as the Belzona product. Belzona is may be more expensive but, if
results are important, is actually less expensive.
www.belzona.com

And speaking of epoxy and bicycles, recumbent bike guy might want to
know, if he's still hanging around here, that there's a carbon fiber
bicycle whose tubes are secured to titanium lugs with epoxy.

Thanks for the tips guys.

Epoxy is pretty much out of the question for me. Kinda hard to find
things like that out here in Denver. Its gonna hafta be machine
screws... that's what I have on hand. The table saw is also packed away
right now.... grumble... grrrr.

I'd use better tubing and just braze everything, but my MAPP gas torch
just isn't hot enuf. Already tried it.

I am going to use another EMT tube running from the bike's down-tube to
the wheel as a brace. This setup is similar to the way old delivery
bikes were made. Most of the replica Wright test-bikes that I've seen
use pannier-style struts attached to the front fork and handlebars. But
this would introduce a lot of lateral motion into the experiment wheel
as the bike is ridden. I'm guessing that the Wright boys knew that and
used a frame-mounted setup.

Smitty Two wrote:

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.

If you're going to do all that cutting on a table saw, then just set the
blade at a 45 degree angle and run a block through twice so that it cuts
a nice V. If you use a 2x4 block, set your fence at about 2.25" from
center and you'll get a 1/2" wide V. Drill a couple holes to bolt it to
the drillpress table. It won't be a permanent tool, but it'll work
perfectly to build one bike.

A further enhancement, I welded a short piece of angle to a C clamp.
Makes holding the tube much easier.

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."

In article ,
Ernest Christley wrote:

Smitty Two wrote:

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.

If you're going to do all that cutting on a table saw, then just set the
blade at a 45 degree angle and run a block through twice so that it cuts
a nice V. If you use a 2x4 block, set your fence at about 2.25" from
center and you'll get a 1/2" wide V. Drill a couple holes to bolt it to
the drillpress table. It won't be a permanent tool, but it'll work
perfectly to build one bike.

A further enhancement, I welded a short piece of angle to a C clamp.
Makes holding the tube much easier.

It seems you're talking about a fixture to drill one piece of tubing at
a time, while I envisioned a fixture to drill all three pieces at once,
while clamped together. I don't have the patience to draw in ascii, and
I know my written description was somewhat lacking.

I think having access to a machine shop has made me more particular
about how things fit, probably too particular. If it were my project, I
wouldn't drill mating holes in any two pieces of anything ever, unless
they were either clamped together, or dialed off to the 0.001 on the
mill. I'll freely concede that that may be overkill for this project.

"Smitty Two" wrote

Anyway, I can see you like the bolts.

It kinda' more in lines with what the Wright brothers would have used, too,
isn't it? I'll bet they didn't have epoxy to put their bicycle wind tunnel
together, right? g
--
Jim in NC

Anyway, I can see you like the bolts.

It kinda' more in lines with what the Wright brothers would have
used,

In keeping with the way the brothers might have done it - how about
drillining 3 holes in a couple of pieces of wood of the diameter needed
to fit the EMT and the bicycle tube, saw in half and bolt together
clamping the tubes together? Might need 3 sets of blocks to keep
things torsionally rigid.

--0-O-0--

====================
Leon McAtee

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.