I need some help with a project: Our club has a portable layout that we haul
from place to place. The legs consist of PVC pipe with plastic caps equipped
with leg levelers. The levelers currently use a threaded brass furniture
insert with a carriage bolt threaded inside and the legs are leveled by
rotating the bolt. The problem is that this is a kind of cobbled approach.
What we REALLY need is an "insert" (for lack of a better term) that is made
of steel (brass is too soft) that is about 1/2" in ouside diameter with a
machine thread, maybe 1/2 x 13, and an inside 1/4 x 20 thread. It needs to
be at least 3/4" long. 1" would even be better. Does anyone know where we
could find something like this, or failing that, where we could get 50 or so
manufactured?
Jeff
On 8/22/2009 11:14 AM Jeff Stanton spake thus:
I'd look into ordinary T-nuts, like these:
formatting link
(you can get ones with longer, skinnier prongs than this)
They'd go on the bottoms of the caps, on the outside, so the weight of
the layout would hold them tight. Drill a center hole for the screw and
four small holes for the prongs, maybe use a dab of epoxy to keep them
from falling out.
Much cheaper and easier to obtain than Robert's pool-table-leg levelers.
We tried the T nut rout for our 2x2 legs on our club layout. The nuts
kept falling out, the bolts would vibrate out and in general it was
unsatisfactory.
We changed to EZ-Lok inserts and hammered the threds befor inserting
into the legs. No more problems.
On 8/22/2009 3:14 PM Chuck Kimbrough spake thus:
There's another kind of T-nut that hardware stores have in the "nifty
little miscellaneous parts" section, that has 3 holes instead of prongs.
One could fasten these to the PVC caps with sheet metal screws, which
ought to hold them in pretty well.
Or you could just forego the caps, epoxy dowel into the end
of the legs, and use plain ole tee nuts. A jam nut threaded
onto the elevator bolt will lock the bolt in position, and
allow for easy adjustment.
fl@liner
Thanks to all for your help. We have tried all the mentioned variations of
T-nuts, but none can stand up to lateral forces generated when the position
of modules is shifted. What we really need is some sort of threaded insert
that can be securely bolted into the cap. In addition, we have found that
epoxy or similar products just don't hold well in PVC pipe.
Jeff
Perhaps the term "insert" is getting in the way. Everything I have found so
far is a self-tapping product. What I really need is something that I can
fasten into my leg caps with nuts, so it needs to be at least 3/4" long,
preferably 1"
Jeff
How about a wood plug with the inside diameter of the cap. screw it in from
the sides so it won't move. drill it and the cap then remove the plug and
put a T nut in and put the plug back and then the cap on the leg.
The problem we have had with T-nuts is that they cannot withstand the
lateral forces of moving the modules around, or even the flexing that occurs
when the modules are leaned on during the normal course of operation. Those
with tabs pull out, even if secured with adhesive, and those with screw
mounting require screws so small that they pull out of the wood. Believe me,
we have tried virtually everything with T-nuts.
Jeff
Jeff, how about a piece of 1/4" pipe threaded on both ends so it can be
bolted into the leg? The problem to me would seem to lie in the thinness
of the pipe cap. Perhaps you could find smaller PVC pieces that could be
used to reduce the inside diameter of the leg to the same as the pipe
outside diameter. If so, you might not need the pipe. Then install a
long machine screw and secure it. I would even consider epoxying it in.
The club I belong to uses eye-bolts threaded into nuts in the caps. Looks a
bit flakey, but you can then use a rod to turn the eye-bolt when leveling
the module. We then use a 3/4" piece of ply 6" square between the ground
and the eye-bolt when we're on dirt instead of concrete. Have had the
occassional problem of the nut popping loose, but we keep spares on hand
during shows.. The modules themselves are light enough that we just get a
few members together and lift them when we need to move them. Can't recall
what we use to glue the nuts onto the caps with though - probably epoxy, but
maybe some of the newer 'gorilla' glues would work as well...
Matt
Actually, I'm getting a little closer to a solution. It appears that the
simplest solution is something called a reducing bushing. They make them
with a male thread of 1/2" and a female thread or 1/4". Unfortunately, the
female thread is a pipe thread, and I need a 1/4 x 20 machine thread. The
male thread can be almost anything. I may have to find someone to custom
make them for us. I appreciate all of the suggestions offered here, but many
of them would require us to go back almost to square one. Our legs and leg
end caps have been purchased or constructed, and all we need is a reliable
adapter to mount the leg levelers.
Jeff
On 8/23/2009 5:16 PM Jeff Stanton spake thus:
I was going to write, before my Usenet access was so rudely cut off,
that what you need is one of these--
formatting link
--except not plastic and with machine threads, as you pointed out.
Regarding threads, I wonder if you couldn't just buy plumbing bushings
and re-tap the threads with a regular tap to remove the taper? I think
the FIP threads are the same as regular machine threads, except tapered.
You also get threaded plumbing adapter and use *steel* caps instead of
plastic ones. You can drill and tap the *steel* cap. Or if more
ambitious, get a solid steel plumbing plug, and drill and tap that.
You'll probably want a (heavy duty) drill press for this.
On 8/22/2009 11:14 AM Jeff Stanton spake thus:
Just ran across this page and thought this guy's shop-made leg levelers
looked interesting (near bottom of page):
formatting link
Of course, you couldn't use these with your pipe legs, but they would
work nicely with wood legs.
"Jeff Stanton" wrote in
news:d_kkm.182505$ snipped-for-privacy@newsfe12.iad:
How about something like this?
formatting link
They're called "insert nuts" and I've found them at my local hardware
store. The style I got drive in with a hex wrench, then the machine
thread bolt inserts into the center.
Puckdropper
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