The clamp lugs are made from 1/2" O.D., .058" wall Chromoly tubing.
This tubing should allow 3/8" threaded rod inside just right. Do you
have different lugs, or have you made them from different tubing?

The lugs are welded or brazed to either side of a slit you cut in the
forward end of the main tube. When the bike is complete you insert
the sliding boom and adjust it to the correct length and position,
then you tighten a couple of bolts through the lugs. That pulls the
main tube tight around the sliding boom, securing it.

There's a picture on the upper-right side of page 9 showing this, if
you can see it properly. I found the pictures in the instructions to
be awfully dim and grainy and not much help, but you can sometimes get
the idea.

I hope that helps.

-Ed

--- In bentechriders@yahoogroups.com, "mnzeiter" <mnzeiter@...> wrote:
>
> Hi - I'm hoping someone can help. I'm starting to work on the frame -
> but I am stuck on step 28 on page 9 of the Bentech plans. It calls for
> a 7" piece of 3/8 inch all thread to hold the clamp lugs in place. The
> clamp lugs I have will not accept a 3/8" threaded rod. It almost seems
> like I am missing a piece - I do not see how the clamp lugs I have is
> going to clamp the sliding boom in place. I've been trying to look at
> the completed frames online but I cannot get a detailed picture of
> that area. I'm sure it's something simple I am just not seeing. Any
> help would be most appreciated - thank you!!!
>