Parts for Binocular
In the design of the binocular
mount, I considered use of a parallelogram mount that could be
attached to the chair base. I decided against this because of
the additional weight this would add to the system and need for
portability and quick setup. The bino mount I built is relatively
light, requires no modification to the reclining chair and can
be adjusted for the size of different observers. This design works
well for a single observer.
Altitude (up-down) position is
controlled by the observer shifting his weight and by leg and
foot pressure on the reclining chair. This is how these reclining
chairs are designed. I used a chair that was given to me by my
daughter that she got free for purchases made from a supermarket.
Look for a chair that is comfortable, well built and easy and
smooth to operate when reclining. My daughter said she has seen
the lawn chair for about $50 at Walmart, "Bed Bath and Beyond"
and "Big Lots".
With the additional weight that
the binocular mount and large binoculars add to the system, I
use bungee cords on the front of the chair to assist with returning
to the upright position and also to balance the large binoculars
on the mount. Use of the bungee cords instead of counterweights,
minimizes the weight of the system. Minor altitude adjustments
while observing can be made by lifting and lowering the binoculars
Right Ascension (left-right) position
is controlled by a DC powered reversible and variable speed drill.
The drill has a switch that is activated with the thumb and forefinger
to change direction. How hard you press on the drill's trigger
determines the speed. The drill chuck also has a clutch that I
found works best at a high setting for my system. The binoculars
can be rotated on the computer tray for observing to a certain
degree, before moving of the chair with the drill drive is required.
The position of the binoculars
from an observer's eyes can be adjusted as needed while observing
since the binocular support (computer tray) is spring loaded.
The binocular mount can be swung upward out of the way for sitting
down or getting up off the chair.
1. Drill a hole in the center
of the computer tray for mounting the 25X100 binoculars on its
center post with 1/4-20 bolt and washers.
2. Make four spacers for mounting
the metal pipe arms to the side of computer tray. The spacers
for my chair needed to be 1 1/4 inch. I used a 1.5 inch diameter
hole saw in a drill to make 8 spacers out of 5/8" plywood.
I stacked two of these spacers for the needed 1 1/4 inch spacing:
3. The sliding computer/keyboard
tray comes with four brackets for mounting the tray under a desk
top. I removed two of the brackets (back) since they were not
needed. I used the other two brackets (front) for mounting a long
spring. I used the existing holes at each end of the sliding tray
brackets to install four 3/16" by 3' bolts for mounting to
the conduit pipe arms.
4. Cut the 10 foot conduit pipe
into three pieces: two 4-foot sections and one 2-foot section.
I marked the location of the holes needed in the two 4-foot pipe
sections to line up with the holes for the 3" bolts in Step
3. Drill these two 3/16" holes through each pipe section
as shown below. Attach two 1/2 inch EMT
to EMT Pull Elbows to the end of the 2-foot pipe.
5. Complete assembly of the tubular
frame by installing the spacers and metal pipes and tightening
all screws of the EMT to EMT Pull Elbows:
6. For attaching the binoculars
to the computer tray, I made two spacers out of 5/8 inch plywood
using a 1.5 inch hole saw and a 2 inch hole saw. Add felt strips
to the front and back of computer tray where the binoculars make
contact to avoid marring the binoculars. Tighten just enough to
allow the binos to be rotated left and right:
7. Place two 1/2 inch conduit
hangers on the tube assembly 23 inches from the binocular end
of the tube assembly.
8. Use a 1x13/32x1/16 flat nylon
washer and a stainless steel washer between the 1/2 inch and 3/4
inch conduit hangers and fasten with a 1/2 inch long bolt and
locking nut. The locking nut will keep the joint from coming loose
in time as the bino mount is rotated.
9. I installed two long springs
from the front brace of the computer tray to an existing bolt
on the back end of the tray. The tension of this spring helps
support the weight of the binoculars when they are pointed near
10. The Binocular Mount is now
complete! It can be placed on the the chair with the two 3/4 inch
conduit hangers positioned about five inches from the top of the
chair on the chair frame and fastened with wing nuts. I used rubber
grippy material found in dollar stores on the tubular frame under
the conduit hanger to prevent marring of the chair frame and to
keep the conduit from slipping out of position:
11. The completed bino mount attached
to the reclining chair. The bino mount can be left on the chair
for transport; it folds flat with the chair when it is folded.
12. Bungee cords were added for
the optimum motion of the chair in altitude. I used two 18"
cords (blue) on the front and two 40 inch cords (yellow) along
with two 32 inch cords (Green) on the back.
Page - Setting Up For Field Use
Big Astronomy Binoculars - Large Astronomy
Detailed procedure for drill-powered
astronomy binocular chair.
Binocular mount for Apogee 25X100 large
Comfortable observing with big astronomy
Reclining chair for large astronomy binoculars.