On Thu, 29 Oct 2009 00:37:07 -0500, cavelamb wrote:
James Waldby wrote:
On Wed, 28 Oct 2009 01:57:44 -0500, cavelamb wrote:
....
Mcmaster ruined my bright idea.

Thread rod couplers aren't all that long. Now, it I could find one 6
or 8 inches long???

You could use the screw and nuts from a wood clamp, if you invert the
arrangement you show in your picture,
http://www.home.earthlink.net/~capri26/#tiller. That is, put the
clamp screw in place of your tube, and put tubes in place of the
threaded rod, with the clamp nuts captured in the ends of the tubes.
The wheel suggested by Gunner could be fastened at the center of the
clamp screw.

It would still take a left and right hand thread to make this work.

I went by the local fastener place today. They can get L and R threaded
rod (but not bolts), which is ok. And they can get L and R nuts.

They also had several sizes of largish turnbuckles. (All of which felt
like a lawnmower full of bailing wire)

By "wood clamp", I meant clamps which each have 2 screws, with several
inches of left-hand thread and right-hand thread per screw. See
http://search.harborfreight.com/cpisearch/web/search.do?keyword=Handscrew
and http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=6987.
In the latter $4 item, the screw diameter is about .28" and one screw
has 2.6" LH and 3.2" RH thread, while the other screw has about 3" LH,
a .5" unthreaded middle section, and 3" RH.

My Jorgensen 10" clamps have 3/8" diameter screws with about
4" LH and RH per screw; my Brink and Cotton 12" clamps have
..45" diameter screws with about 6" LH and RH per screw.


--
jiw