Telescoping
Metal Pole
This pole can be extended from 5' to over 8' high. It is
easy to make and costs about $6 per pole (year 2000 prices!)
It is suitable for bluebird houses since they are light and will not
overload such a long pole. The birdhouse can be lowered for inspection, then
raised up to its higher position for safety.
Parts needed to make two telescoping metal poles:
2 pc 1" EMT Conduit 10' (about $8)
1 pc 3/4" EMT Conduit 10' (about $2)
4 pc 1/4 x 1&1/2" bolt with matching wing-nuts (2)
and hex nuts (2,) (about $1)
2 pc 1/4 x 2&1/2" carriage bolt with washer and nut (for
attaching houses to pole)
2 pc #8, ¾" sheet metal screws
2 pc 8" 16 gauge galvanized wire (for attaching houses
to pole)
Tools needed:
Hacksaw, vice, drill or drill press with drill bits, pole
driver, level, metal file, pliers, screwdriver, wrench set. [Note: often a store
like the Home Depot will cut the conduit to any size for free. In this case you
do not need the hacksaw and vice.]
To make it:
=== Cut the two 1" EMT to 7', 8' or 9' (your height
plus 18" to 24".)
Use the vice to hold the conduit as you use the hacksaw. Save the short pieces
for some other project.
=== Drill a 1/8" hole 4' 6" from ONE end of each
of the 1" EMT pieces. The hole should go clear through the metal pole (you
will drill through two surfaces, along the diameter of the pole.) If you need to, you can use a center punch to mark
the starting point for the drill bit not to slide. Usually a small hole like this is
easy to start without a punch mark. Start to drill slowly, once the drill bites
you can drill with more force.
=== Drill these same holes larger to 9/32" (drilling a
hole in metal requires first a small hole, then the second time use a drill up
to the size wanted.) It is a good idea to file the "burr" which
results from drilling in metal. Now you have two pieces of 1" EMT, each
with a hole through it about 4' 6" from one end.
=== Put a 1&1/2" bolt and nut in each of the two holes just
drilled. These will act as a stop
to prevent the inner rod from falling through inside the outer rod and disappearing on
you…
=== Measuring
from the same end, make a second hole in each of these two pieces, this
time 18" from the end. Again
start with the 1/8" bit, and then the 9/32" bit.
File the metal burr. This
hole represents the "highest" position of the bottom of the inner tube
when it is used to lift the nestbox. You
can make more holes for positioning the nestbox at other heights. [Recommended: make two more holes at 24" and 30" in
each piece, measuring from the same end as before. This gives three heights for the pole.]
The
diagram shows the relative positions of these four holes in one of the two pieces,
the second piece is identical.
=== Drive these two pieces of 1" EMT into the ground
using the pole driver. MAKE SURE THE right
end shown above IS at the bottom. Driving a pole into the ground takes about 5
minutes (less if my 19 year old son is helping). As you drive it the first few inches, check using the level that it is going down straight
(vertical.) Put the level along the
conduit and check at two points around the pole, 90º apart. Drive these EMT
conduit down into the ground till the top of the conduit is at the level you
want the nestbox to be when you monitor it. Checking for vertical is not essential if you have a good
eye for it. I often look against the corner of a house to tell vertical
quite accurately.
=== Cut the 3/4" EMT conduit in the middle (result:
two 5' pieces).
=== Attach the houses to the ends of the 5' pieces just
obtained. Best way is to use one or two carriage bolts through the box and the
pole with nuts and washers. First drill a hole one inch from one end of the ¾"
EMT. As before, start with
1/8" and finish using ¼" drill bit.
I use one 1/4 by 2" carriage bolt, washer and nut at the top of the box, and a wire
through two holes in the box around the pole and I twist the wire ends around the
pole. This ties the bottom of the
house to the pole, while the carriage bolt holds the box tight to the pole.
Click on the image to the right to see a larger view. [Note: the second 1/4"
hole seen at the top is not needed in this application.]
=== Insert the thin pole (with the house attached) into the
EMT which is in the ground. It should be at eye level where you can inspect it when
monitoring. Raise the box up and put a bolt and wing-nut in one of the holes in the 1" conduit which
is in the ground. This bolt is the "stop" for the
inner conduit at the height you like when the box is raised to its higher
position.
=== Make sure the inner conduit is resting on the 1/4" bolt. If this is not the height you want,
there are two other heights to choose from. Now orient the box in the
direction you want. In general it is OK to let the entrance hole face any
direction except West. Your specific location may dictate the direction to
orient the box. Drill a hole 7/64" through both the outer and the
inner conduits (but don't drill clear across to the other side of the pole.) Now screw
the sheet metal screw (3/4" #8) to hold both conduits together. The first time
the screw is driven into the holes, it will be hard since it has to cut the
thread as you drive it in. In the future it will be easy to take it out
and drive it back in. the purpose of this screw is to prevent the box from
facing the wrong direction and to firmly hold the two parts of the pole
together.
Operation:
=== To lower the box, remove the
3/4" #8 screw, then remove the bolt holding the inner pole up. Make
sure to hold the box so it will not fall down suddenly or too quickly, and guide
it down to the lowest possible level for inspection. When done, raise it
up and place the bolt back under the inner pole. Replace the wing-nut and
tighten it a bit. Rotate the box and when the two holes match, insert the
3/4" screw back and tighten it.
That is all! If you have any questions or need more detail,
please send me e-mail.
Fawzi Emad, Laytonsville, MD <femad"AT"comcast.net>