That was it. There is a 2" aluminum tube over a 1 1/4" stainless steel
"jackshaft". It's held with two 1/4" bolts. Holes thru aluminum tube were
elongated. Drilled to 3/8". Unfortunately, these aren't perfectly round,
either, since I drilled 'em with a hand drill, but I'm hoping the torque I put
on the 3/8" bolts will crush the aluminum tube into clamping on the stainless
steel. We'll see. If not, I can drill more holes thru that assembly and put
more bolts in. It seemed more solid, but next big wind, I'll have a look.

Thanks again for the tip.

Dave Head

On Sun, 22 Feb 2004 14:46:54 -0600, "Crazy George"
wrote:

Dave:

From that description, I suspect you are going to find all the bolt holes in
the tubing elongated from torque. We usually drill slightly oversize holes
for our fasteners, but in this high stress application, the holes should
start undersize so the fasteners have to be driven in and are tight from the
get-go. Also, it is necessary to select fasteners which do not have threads
where they pass through the walls of the tubes. This is often the most
difficult challenge.

Dave:

I've forgotten the exact construction you described, but I suspect you are
going to have to increase the friction between the two tubes by splitting
and clamping the outer. It sounds like the aluminum is simply too thin and
too soft to withstand that kind of torque against a small diameter fastener.

--
Crazy George
Remove N O and S P A M imbedded in return address
"Dave Head" wrote in message
...
That was it. There is a 2" aluminum tube over a 1 1/4" stainless steel
"jackshaft". It's held with two 1/4" bolts. Holes thru aluminum tube were
elongated. Drilled to 3/8". Unfortunately, these aren't perfectly round,
either, since I drilled 'em with a hand drill, but I'm hoping the torque I
put
on the 3/8" bolts will crush the aluminum tube into clamping on the
stainless
steel. We'll see. If not, I can drill more holes thru that assembly
and put
more bolts in. It seemed more solid, but next big wind, I'll have a look.

Thanks again for the tip.

Dave Head

On Sun, 22 Feb 2004 14:46:54 -0600, "Crazy George"

wrote:

Dave:

From that description, I suspect you are going to find all the bolt holes
in
the tubing elongated from torque. We usually drill slightly oversize
holes
for our fasteners, but in this high stress application, the holes should
start undersize so the fasteners have to be driven in and are tight from
the
get-go. Also, it is necessary to select fasteners which do not have
threads
where they pass through the walls of the tubes. This is often the most
difficult challenge.

On Sat, 28 Feb 2004 20:10:56 -0600, "Crazy George"
wrote:

Dave:

I've forgotten the exact construction you described, but I suspect you are
going to have to increase the friction between the two tubes by splitting
and clamping the outer. It sounds like the aluminum is simply too thin and
too soft to withstand that kind of torque against a small diameter fastener.

Hi George,

I took the antenna down last weekend (layed it over using the screw operated
hinge base) and, after considering a few alternatives, and trying one
unsuccessfully (new bolt hole - broke off bit), I drilled out the 2 1/4" bolt
holes already there that were holding the hollow mast to the stainless steel
shaft to 3/8". Installed 2 3/8" bolts and tightened them down very tightly.

We've got a moderate wind right now, and the antenna is doing about 5 degrees
of swing, so i think it helped. Will probably tilt it over in a couple weeks,
drill some more 3/8" holes, and tighten them down smartly as well.

BTW, for anyone with a quad that has "hose clamp" construction to hold the
spreaders, it pays to retighten them. Nearly all of mine were stretched, and
this antenna hasn't been up all that long - a few months.

Dave Head
K8DH

BTW, Dave: If you ever do disassemble that tubing over tubing joint, put a
solid block of something inside where the bolts go through. No tubing is
strong enough to resist collapse when you tighten the through bolts enough.

--
Crazy George
Remove N O and S P A M imbedded in return address
"Dave Head" wrote in message
...

snip
We've got a moderate wind right now, and the antenna is doing about 5
degrees
of swing, so i think it helped. Will probably tilt it over in a couple
weeks,
drill some more 3/8" holes, and tighten them down smartly as well.

BTW, for anyone with a quad that has "hose clamp" construction to hold the
spreaders, it pays to retighten them. Nearly all of mine were stretched,
and
this antenna hasn't been up all that long - a few months.

Dave Head
K8DH

On Fri, 5 Mar 2004 20:24:59 -0600, "Crazy George"
wrote:

BTW, Dave: If you ever do disassemble that tubing over tubing joint, put a
solid block of something inside where the bolts go through. No tubing is
strong enough to resist collapse when you tighten the through bolts enough.

Hi George,

No, its tubing over a solid steel shaft. The shaft isn't going to deform. The
(aluminum) tubing, which is the 2" mast for the antenna, _will_ deform
sufficiently to clamp onto the SS shaft. That seems to be retarding the
excessive swinging in the wind now, but I think it might be made somewhat
better. A couple more 3/8" bolts, in a couple new holes thru the assembly
should help, I think.

Dave Head