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4-vane mounts

3-vane mounts

Curved mounts

Cassegrain mounts

ULS Quartz secondary mirrors

Pyrex secondary mirrors

Hi-tack flocked light trap

FlockBoard flocked light trap


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Information You Supply When Ordering Secondary Mounts

There are three dimensions you need to provide ('A', 'B', and 'C' below), and any optional features you want to add. If you have any questions or are unsure how to take these measurements, feel free to call us before placing your order.

1. Provide basic dimensions

Dimensions to provide for a
solid tube telescope

Dimensions to provide for a
truss-style telescope
(upper cage shown)

Dimensions to provide for a
curved secondary mount in a
solid tube telescope

A = The actual inside diameter of your tube or upper cage. Provide the actual inside diameter of your tube or cage. We will make your spider slightly smaller (about 1/4" smaller) than this so it can be properly tensioned and centered. A measurement accuracy of +/- 1/16" (+/- 1.5 mm) is sufficient.

B = The size of your secondary mirror (minor axis). In most cases, you will have a standard English or metric sized secondary mirror. If you feel your mirror is non-standard or custom-made, please measure the minor axis as accurately as you can.

C = The tube wall thickness. If it is a truss-style scope, please provide the strut diameter (the strut is what the spider will attach to). This dimension is not important for making your spider, but it lets us put the proper length mounting screws into your kit.

2. Optional features

Protostar straight-vane secondary mounts can be ordered witha finger adjustable collimation kit, antidew heater, and custom offsets. Read the options page for more information.

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Protostar, P.O. Box 368 New Albany, Ohio 43054 U.S.A. 614-375-3146
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