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Questar logo from 1990's (27,482 bytes)

Company Seven’s recommendation for fine tuning alignment of the Tristand or the Astropier.

Company Seven’s Riser attached to a Questar Tristand Head (72,480 bytes).

Overview: the Tristand and the Astropier each consist of a geared adjustable head with telescope platform that is attached onto a cylindrical aluminum pier supported by a tripod leg set that can be folded in for convenience in transport or storage. These were developed specifically to rigidly support a fork-mounted Questar 3-½ telescope, and to facilitate the precise aligning of the telescope mount to the celestial pole. When the mount is 'pole aligned' then the motorized base of the telescope rotates the fork and telescope optical tube assembly with enough precision to counteract the rotation of the Earth on it's own axis. By moving the telescope at the same rate as which the Earth rotates about it’s axis, about one rotation every twenty four hours, the telescope can track a celestial object precisely so that the object of study remains centered in the field of view of the eyepiece.

Right: Tristand and Astropier Leveling Screw, one of three in the set, shown at Company Seven alongside the leg tip of a pier (32,345 bytes).

The Tristand and the Astropier share identical top (head) and lower (folding legs) sections, only the length of their piers differs. The head of the Tristand is the same as we provide on the taller Astropier, and this head incorporates geared controls to adjust the tilt and azimuthal (left to right) orientation of the attached telescope mount. The gearing of the head is fine enough to align the mount and lock it in place with enough precision to facilitate visual studies however, some of our customers engage in long exposure astrophotography and for this they will obtain better results if the Tristand head can be adjusted with very fine precision to align with the Celestial Pole. To attain that fine extra bit of alignment precision the Leveling Screws set were developed. A secondary value is that even for simpler visual uses they can aid in leveling the pier to improve stability when operating on uneven ground.

When properly employed this accessory does not compromise the rigidity or the stability of a Tristand or Astropier.

Arrangement: each of the three Leveling Screws provided in the set consists of a threaded stainless steel jack screw mated to a precision-machined foot, this foot is made of a hard plastic that tapers down in diameter to a narrow flat bottom. The Leveling Screw includes a precision-machined locking disc perforated and threaded to be be run up the steel shaft and to lock the screw extension at the desired length. This locking disc features diamond-pattern knurling around it’s circumference to make it easier to distinguish from the foot of the Leveling Screw. Each has an overall length of 3-¼ inches from the flat of the foot to the top of the jack screw. The Leveling Screw set is fully precision machined in the U.S.A.

For some clients we have modified the design plan to make this of other materials, or with a sharp tip, or different thread bolt.

Installation And Use: each Leveling Screw threads into the threaded hole from the underside at the tip of the pier leg. No tool is needed to install or adjust the Leveling Screw.

If one seeks only to level their pier on uneven ground, then adjust each Leveling Screw to reduce or fully eliminate that undesired tilt. This can be accomplished by sight or with the aid of a simple inclinometer, or with some compasses that can double as an inclinometer such as some included with a smart phone.

If your goal is to obtain a good polar alignment, then we recommend you adjust the manual controls of the Tristand Head to align using visual references to the pole. In the case of the North Pole, we refer to Polaris and Cassiopeia for example. Once the telescope is reasonably well pole aligned lock the Tristand head tilt and azimuth controls. To obtain the more precise polar alignment you can then adjust the Leveling Screws but you will need to guesstimate which Leveling Screw(s) will need to be adjusted, and how far each may need to be moved in or out; you can guesstimate this by applying slight pressure to the Tristand Head platform to see which direction of shifting the platform improves the alignment.

Particularly when aligning the taller Astropier it can be helpful to have a helper at the telescope eyepiece to judge how the adjustment to each Leveling Screw affects the alignment to the celestial pole, or if employing the star drift alignment technique then how the adjustment corrects for the drift of a star.

When the desired extension of each Leveling Screw has been reached, the knurled ring is run up against the bottom of the pier foot tip, and once snug this locks the jack screw in place at the desired height.

For transport or for storage Company Seven recommends our clients thread the Leveling Screw all the way in (retracted) to reduce chances of damaging the assembly. The Leveling Screws can be left attached, even when storing the pier in our optional fitted carry bags.

Leveling foot attached to a Questar Tristand, retracted (37,761 bytes). Leveling foot attached to a Questar Tristand, extended (35,860 bytes).
Above: Leveling Screw attached to an Astropier foot at Company Seven. Shown at left retracted (37,761 bytes), and at right extended (35,860 bytes).

For more information about how to work your way through the decision making process of choosing and specifying a Questar 3-½" telescope, the common accessories, and desirable options please feel free to call us or send an E-mail inquiry, or visit our showroom. You may find more help by referring to the articles in our Questar Library section on line.


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