Binocular Chair Usage and Functionality

This binocular chair has components designed by Milky Way Lounge. See the usage and functionality details below:

Overview:

Comfort	Relaxing for head, neck, upper and lower body; a sleep inducer!
User height/size	Adjustable for typical user heights and weights, including adults and teenagers.
Teeter holder	Fine adjustment of the viewing elevation, with one hand. Used in combination with the cradle described below.
Binocular cradle	Used in combination with the teeter described above. With the same hand, fine adjust the eye-to-binocular position. Used when other large viewing elevation changes have been made. The cradle fulcrum options can match to the binocular’s center of mass.
Chair rotation	Easy smooth azimuth control while the other arm is controlling elevation.
Binocular weight balance	Adjustable with rear counterweights. Doesn’t need to be exactly matched because of added friction.
Chair backrest tilt	For course elevation changes. A zero gravity chair is best suited but a reclining lawn chair can be used.
Chair-front counterweight	Weight-assists when tilting the backrest of the loaded zero-gravity chair, and prevents tipping the chair.

Functionality and stability:

View direction stability	No drift, due to added friction for both azimuth and altitude. Also true when the hands are released, or when the ground is not completely level.
View direction bounce-back, after setting the view direction	Almost zero, due to choice of materials.
Head/eye positioning to binoculars	The eye distance to the oculars and the angle with the oculars are both completely adjustable.
Head/eye position as elevation changes	The eye position tracks the binocular position very well, and can be adjusted for neck cushion thickness and user body size.
View settling time	Negligible, due to the stability rods.
Elevation drift	Negligible, due to the stability rods.
Body pulse vibration aka. “heartbeat”, seen in the view	Mitigated by the stability rods, and better in general with a sturdy chair. More noticeable on bright stars at high magnification, and less noticeable on extended objects.
Elevation extent	A zero gravity chair typically tilts back to about 75° of elevation, then the teeter can tilt up past zenith, as the neck is slightly arched. With a cushion on the nape of the neck, this can also be comfortable.
Tested with	10×50’s, 16×70’s, 82mm 20-60x fieldscope

Easy assembly:

Sections	5 to 6 sections. The heaviest and bulkiest section is the zero gravity chair itself.
Setup time	A few minutes: stack the base sections, place the chair with its attached binocular holder, slide in the chair front counterweight, and clamp on the wheel mount crossbar using the two nylon wingnuts. This excludes transport time.
Collapsible	The zero gravity chair is collapsible with the teeter/cradle and stability rods installed, otherwise easily remove them with the nylon wing nuts.
Stacking	The turntable bearing section (see pic below), is flipped over and just sits in the friction cavity of the octagonal base. The chair is opened up with its binocular holder, then placed on the four rubber guides on the platform section (see pic above). The large heavy duty turntable bearing reduces tipping and wobbling.
Self-adjustable wheel mount	When clamping on the wheel mount crossbar, it conforms to the geometry of the chair frame, and self-adjusts to the required height off of the base track.

Body strength to operate chair:

Arm strength to operate azimuth and the fine elevation controls	little
Torso strength to tilt back a zero gravity chair	moderate
Leg/arm strength to return a zero gravity chair to upright	moderate
Strength needed to transport and assemble the sections	moderate

Cost and commitment:

Parts and materials	From recommended external sources; total ~US$275, excluding the zero gravity chair.
PDF plans	~1/4 of the above number; discounts available.
Tools	Table saw, cross-cut saw, power drill, small belt sander, common hand tools. A router and a drill press are great but there are workarounds shown in the plans. Safety: dust mask, safety glasses, ear protection, ventilation for the finishing.
Time commitment	A few days to acquire the parts and to do some organization, then a week or two to build and adjust the components. The plans accommodate your chair dimensions, but expect some trial and error as you fit your new components.

This work © 2024 by Milky Way Lounge is licensed under CC BY-NC 4.0