Sometimes a picture is worth a thousand words. This is the case here.  Below are shown some ways to attach the ST-7 to the rear of an LX200.  Anyone can do that so what's the big deal?   A few of the attachments are a bit unusual.  On the left is shown a parfocal adapter for use with the ST-7 that gives parfocallity with the ST-7 with the Optec 0.33 reducer attached.  As is shown in another place on this web site. It is not possible to place the focussing attachment between the Optec focal reducer and the CCD chip because it has to be only 29 mm from the chip.  When the parfocal adapter is outside the focal reducer it requires almost 8 inches of extra tubing to be made parfocal.  The adapter shown does just that.  A diagonal makes the direction more convenient and a 12 mm Celestron illuminated eyepiece is used for precise focus and centering.  Final precision focus is checked using the ST-7 image directly.

As shown in the left-center picture, the adapter can be used directly on the JMI focuser. After close focus and framing is established,  the ST-7 is plugged in in place of the parfocal attachment as shown in the right-center picture.

On the right the parfocal attachment is shown mounted with the ST-7 on the Van Slyke Slider mirror attachment.  Notice that every thing is attached with short 2" tubing to ensure rigidity of the connections.  In all cases two set screws are used to insure integrity of the connections.
 

The slider can also be used with the smaller parfocal attachment and the ST-7 directly, in the compact arrangement shown at the left . At the left-center the slider is shown with the 0.63 focal reducer in place.  It goes between the JMI and the Slider  The combination of the slider and the tubes places the focal reducer at the correct distance from the CCD chip to give 0.63 reduction.   The normal connection of an eyepiece is shown in the right-center picture.  Even hear there are two hidden modifications.  At the right can be seen the v-grove cut into the tube to ensure it locks firmly into the JMI focuser.  With the grove, the set screws can be loosened enough so that the diagonal can be rotated without danger of falling out.  Additionally, the diagonal has had a 48 mm filter ring added so that standard 2" (48 mm) filters can be used at a convenient location.
 

I will soon add some pictures of the above attachments adjusted to take account of the AO unit which I am about to mount on the ST-7.  These attachments might seem like a lot of stuff to hang on the rear of the LX200, but they go on either a 10" or 12" and each has the Meade big blue dew hood on the front which needs weight on the rear to balance it anyway.

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