ETX TECHNICAL TIPS
Your red dot Celestron finder will be a great addition to your ETX; I have one on my ETX 125 and it really helps in "knowing where you are looking." Because the tube is so short, you really cannot look down the tube to aim (like a rifle), so the red dot works good....but there are some things you must know!
1) the finder mounts on the black REAR cell (that rest in the fork arms) on the TOP for your convenience; put it anywhere that it DOES NOT interfere with the scope rotating through the fork arms, or storing in the box when not in use;
2) the finder is supplied with TWO (2) mounting plates; you want to use the THIN one; it has two holes, but you will NOT use the holes.
3) there are two methods to mount and you MUST be careful to make SURE you are putting the finder where you want it to be, because the mount may be permanent. First, after you have checked to see where you want it, position the mounting plate and draw with a pencil a light outline directly on the black rear cell of the ETX 70 using the mounting plate as a template. You can use TWO things to mount the finder: a) foam double-sided tape: this is good and NOT permanent (you have to "roll" the adhesive off if you remove) BUT if you mount improperly, you will NEVER be able to align the finder to the main telescope (SEE BELOW); AND b) your second mounting option (permanent) is to use SCOTCH heavy-duty double stick clear tape (found in the hardware, not office, section of a big store like Home Depot or Lowes): using this tape allows for a very tight and good fit and results in easy alignment.
NOW - regarding the foam tape which is what all suppliers of these focusers recommend: if you use foam tape, the thickness of the tape itself puts the finder so high above the optical telescope tube that you CAN NOT adjust downward far enough to align the finder. Thus, if you so mount, you must put a SECOND LAYER at the REAR of the mounting plate to TILT the plate and finder downward at an angle that will allow proper scope-to-finder alignment.
Good luck...you'll like the finder (I mounted mine permanently since it has the "dove tail" base which allows you to remove it if you need to).
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