Sidewinders, Targetrons & Zerotators use the same port rings and require an optional Docking Port Ring to attach directly to your scope's existing focuser or SCT's visual back. This separate ring design creates a more versatile Sidewinder that can be used on literally any scope on the market. Just pop the circular dovetailed (flanged) ring into the front input body of the Sidewinder and tighten the two SS thumb screws and single 8-32 set screw that are opposed by 120 degrees. The flange provides a failsafe coupling between the docking port ring and the housing of the Sidewinder. Tightening the three set screws around the angled flange actually draws the port ring into the flat surface of the housing creating a bond that is as solid as the 6061 T-6 aircraft aluminum itself.
VSI offers a myriad of very special [exclusive] adapters, couplers, and accessories that no one else could begin to duplicate. This unique offering allows you to build an extremely flexible imaging train, that is not even rivaled by professional research observatories, but envied.
QUALITY ASSURANCE NOTE: It has come to my attention that others use less than adequate coupling methods on their products that induce flexure. They look very similar to VSI's exclusive docking/coupling systems. They are NOT! VSI's exclusive docking/couplings are not like any other flimsy, flexure-ridden connections used on other products. A good analogy would be a comparison between a (less than) $50 and a $300 (and up) rifle scope. The lesser rifle scopes looks identical to the more expensive ones but, in operation, the differences are very apparent, optically and [especially] mechanically. Let the buyer beware, you receive quality and functionality only when you are willing to expend an appropriate dollar amount. VSI's proprietary flared flange (circular dovetail) docking inserts have extremely thick-wall construction and are locked in place by three set screws opposed by 120 degrees. When you tighten these set screws against this special [angled] flange, it not only pushes directly against the insert ring, but it also pushes laterally to compress the ring inwards against external and internal shoulders, which locks it in place like a good weld - rock-solid! - PBVS
|Coupling Port Ring, 2.9" to 2.9" back-to-back flange, Item
This 2.9" back-to-back flanged coupling ring is primarily designed to couple a Sidewinder's input to a Zerotator's output (as part of the super stack, etc.), via the 3 set screws that are opposed by 120 degrees around the edge of either product. Or any other similar 2.9" format application. This coupling ring consumes about 3/8" of profile. Usually this type of 2.9" coupling ring has a shorter 1/8" profile. However, this extra 1/4" of profile is necessary for clearance between the Sidewinder and Zerotator.
|Coupling Port Ring, 2.7" to 2.9" back-to-back flange, Item
This back-to-back flanged coupling adapter will allow you to couple a (now discontinued) MicroGlide focuser, with it's 2.7" docking format, to the output of a Sidewinder, Targetron or Zerotator (2.9" format), via the three set screws that are opposed by 120 degrees around the output of the three items above. The profile of the coupling is about 1/8-inch.
|Coupling Port Ring, 3.1" to 2.9", back-to-back flange, Item
This back-to-back flanged coupling adapter will allow you to couple a Sidewinder, Targetron or Zerotator to the output [moving tube] of your 3" MacroGlide ALPHA or OMEGA focuser, via the three set screws that are opposed by 120 degrees around the edge of the MacroGlide's moving tube output. The profile of the coupling is about 1/8-inch.
|Extension Flange, 3" Outside Diameter for Targetron/Sidewinder rear
This extension flange has a male 2.9" outside diameter circular dovetail flange on one end, and a 2.9" inside diameter on the other. It will extend the rear port of the Targetron to accommodate special reverse parfocusing requirements. Normal installations should not require this extension, but in some circumstances, this may be the only solution. It should not be used unless necessary because it extends your profile, which is a NO-NO! However, if you can spare the profile, and need this extension to address a reverse parfocusing issue, then this extension flange may be what you need.
1" Extension Flange (shown), Item EXT1: $89
2" Extension Flange, Item EXT2: $99