Last updated: 26 January 2007
Subject: ETX-ZOOM Sent: Wednesday, January 24, 2007 12:22:42 From: firstname.lastname@example.org found your ETX-side a few hours ago and maybe this is of interest for anybody. Since a few days i own a ETX 90-PE mount(not the optic) and fixed -due to lack of ETX OTAs- a Soligor Zoom lens 500-800mm in the tang-arms of the mount. Easy. A piece of wood 2 screws each side, a hole for the foto-screw, thats it. Nice but useless ;))
i thought i am too stupid when trying to use the Autostar as the scope pointed always anywhere but not to the selected object. It took a few hours (right now) to find out that this kind of mounting a scope to the ETX is basically wrong. Why ? well, it now has a wrong angle of 90 degrees. The scope must point in the direction of the two tangential-arms and not misplaced by 90, right ? Poooh ! now i need another solution how to fasten a scope (which has not the ETX tubering) on my ETX. But tell me: would you refuse a ETX+Autostar for 50 bucks ? ;)) Just kidding.... I searched your site but did not find a hint that somebody uses another scope on the ETX. Well, its a ETX side ;) But maybe you have an idea ? would be pleased to hear from you again.. greetings from Luebeck NorthGermany ArnoMike here: Hum, that's true about the fork arm adapters. Maybe our resident AutoStar expert Dick Seymour has an idea about changing the AutoStar to handle that.
i guess it is a question of the stoppers inside the RA drive fork. The Autostar and the encoders dont care how a scope is mounted. How about modyfing them: either -------- --disassemble (and replace somewhere else)for non-ETX use --assemble again for ETX use dont know how to fix that yet. or ------------- replace the finger at RA-drive fork-side. The finger rotates against the stoppers, blocking the RA within 90 area. If i would try to rotate the finger by 90 .... ...yeahh, i think that is the solution. Unfortunately you can not turn the finger.... understand what i mean or shall i make a foto ? best regards ArnoMike here: True there are hard stops that will be a problem. Your solutions might work.
From: richard seymour (email@example.com) You have three ways to "fix" your problem: (1) In the Autostar, simply change the -sign- of the Alt/Dec Ratio. (setup>telescope>Alt/Dec Ratio). That will reverse the fork motors, and the Soligor will be able to explore the heavens. It will still not be able to drop -below- horizontal, but it will be able to go "up". (you change the sign by moving the cursor left with the slew arrow, then tap the scroll arrow to change it from + to - ) (2) rework your "cradle" so that the original ETX support is "behind" the lens, instead of under it. (3) open the motor-side fork and remove the "hard stop". I don't know which model (new/old) ETX90 you have. The only DEC hard stop i have seen "removed" was an ETX105 which broke the metal casting (see: http://www.weasner.com/etx/archive/feedbackSep03/autostar.html and scroll far down to the photo, or search for the name "Hawkins") There is probably a corresponding plastic bit on the rotating component that might be easier to remove. have fun --dick
One more thing... turn the Soligor around so it is facing -away- from the RA/Az Clamp handle. As shown in the photo there is a second hard stop which will prevent further "up" motion, but if you arrange it so that the motor fork is on the -right- when you are behind the camera, then the cradle will be able to point the lens straight up (and over) have fun --dick
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