Here's a video showing the (almost) right way to install the dovetail bar in the saddle. Mounts of all kinds have standardized on this style of saddle so that tube assemblies, cameras etc. can be easily moved from one mount to another. There are two standards - Vixen, suitable for small to medium telescopes, and Losmandy, for large telescopes. Yours is Vixen. When installing a scope/ring combination at once, the saddle should be in the horizontal position - rotated 90 degrees from the video - with the knobs on top. Loosen them enough to drop in the bar from the middle as is done here. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Fu4HWgkRP2g.html
The dovetail bar is meant to be angled into the saddle from the middle, then put flat against the saddle and the bolts tightened (not too much, just finger tight). This should be done so that the dovetail bar is level - so in this video, rotate the saddle 90 degrees so that the knobs are on the high side. Remove the rings while doing this.
Could you just take the primary mirror out and place the telescope against a white wall or simply just cover the open area with paper or something white ? Or perhaps make a custom backplate with the center having a circle to enable more accurate if youre using a laser.
Those annoying non counter sunk bolts are that way for a reason. It is a safety feature preventing your OTA from sliding all the way off of the mount if your tensioner is not tight enough.
Actually that setup is to correct cone error in pointing - to get the tube exactly parallel to the RA axis. But yes that also works as a safety feature.
Hello I saw your video & I know my question isnt exactly about the telescope in the video but I thought Id take a chance & ask a question I desperately need an answer to. I recently was given the celestron starsense explorer dx 130az but its didn't come with the tripod. Im sure celestron sells a replacement tripod for this. I kind of looked around and the ones I found on celestron site were very high. What im wanting to know is if they make an off brand or cheaper tripod for this telescope. What type of tripod is exactly needed for the celestron starsense explorer dx 130 telescope? Thank you so much!! ANY INFO WOUND BE GREATLY APPRECIATED
I own a Celestron 114GT (15+ years), another Bird-Jones Newtonian Reflector and totally concur about the need for proper collimation. Excellent explanation about the need to go 'back and forth' checking alignment of secondary and primary, until laser beam remains centered. I use my Cheshire for first aligning the center of all elements, then use the laser collimator for final collimation but unlike you I keep my Barlow Correcting lens intact without an issue (the laser dot is magnified (!) but still centerable). It's an excellent telescope! I have read too many negative posts regarding the Bird-Jones style telescopes which use cheaper-to-manufacture Spherical primary mirrors, rather than true parabolic mirrors in a true Newtonian configuration, where the outer light rays do not come to the same focal point as the center rays. Thus the corrector lens appears to discard the outer rays, and keeps only the central portion rays, thus causing a magnification increase (noted by larger focal length in Bird-Jones telescopes of similar mirror size in true newtonian but with only half the focal length). You lose some light as well so that camera require more exposure times. I've just added the SVBony 8-24mm Zoom Lens (very sweet!) and will be acquiring the SVBony SV305 color camera later this year, and controlling my 114GT via laptop running Stellarium software (highly recommended!).
Thanks for superb instructional video. You really should be writing the owner manuals for Celestron. Two questions. When you ensure that the laser is hitting the centre of the primary mirror, don’t you need a central mark on the primary? And you did have a centre dot on the primary, would that stop the laser beam from being reflected? Thanks to anyone who can help.
Thank You Thank you Thank you!!!!! I just bought a laser Collimation tool for my AstroMaster 114Az. Guess what? I encountered the same problem you identified with the laser due to the correction lens. God Bless You Tube and Mr. Roupe. I Followed the steps and now have a crystal clear image. Looking forward to Aug 25 - Sept 2 to snap some photos of the moon now. You Rock!!!!!
Great video. I own the exact same telescope you used in the video. Unfortunately I found a big issue with my scope, which has to do with the focusing tube. I found it impossible to collimate my scope and after watching many how-to videos and read several instructions, I finally discovered my problem. On my scope, the plastic focusing tube mount was not manufactured correctly, causing the focusing tube to be at a slight angle vs perfectly perpendicular to the scope main housing and secondary mirror mount. This causes issues getting a perfectly clear view, at almost any focusing position, since the reflection off the secondary mirror will never be perfectly centered thru-out the entire focusing tube. The manufacture had tried to correct this by installing a adhesive backed vinyl shim to the inside of the focus tube mount. They were attempting to correct the angle of the focusing tube, once re-installed into the mount. Unfortunately, they did not get the angle corrected, only close enough to get the scope "somewhat" collimated. Since Celestron does not have replacement housing parts for such a inexpensive and basic beginners scope, I decided to see if I could correct the issue myself, by placing adhesive shims (multi-layered scotch tape) to specific points inside the focusing tube mount. I then removed the rear primary mirror, made and installed a collimation cap. I completely reset and re-aligned the secondary mirror, as you explained in your video, but also using the collimation cap without the primary mirror installed. This appears to be the best way to obtain a perfectly or as close to perfectly aligned secondary mirror to the focusing tube. This is something that should be checked on every Bird-Jones style Newtonian telescope, and not assume the tube is correct and perpendicular to the main housing from the manufacturer. Once that is completed, then I was able to continue withe collimation procedure and correct my scope. One way I was able to verify the focusing tube alignment, was quite simple. Just remove the front main housing dust cover and eyepiece (if installed) from the focusing tube. Move the focusing tube all the way down, look at the refection inside the focusing tube and begin to raise the focusing tube upward. while slowly raising the focusing tube, look at the outer perimeter of the reflection and see if it begins to look off-center in relationship to the tube opening. If all is correct and perfect, the reflection should be centered ALL height positions of the focusing tube. If not, the focusing tube needs aligned BEFORE collimation is performed.
Thank you very much for the tape tip. I've just collimated my 130EQ and the wobbly tube was the only thing I disliked about this scope. Looking forward to trying it out on some clear sky.
You could have avoided all that work by using a Collimating Cheshire Eyepiece! With Bird Jones Style Newtonian's that have that corrective lens, it is best to use a collimating cap or eyepiece that is not laser. www.ebay.com/itm/311823543773?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
My telescope came without the power module attached to the end of the telescope, rendering it useless because there's no way to power it on.... a little awkward production error since it's the most important piece
Thanks, this helped. First telescope I've ever owned and as with most things in life the instructions left a lot to be desired. Think I got 'er together now!
Nice Job explaining this process, Thanks for the careful step by step instructions. I'll have to buy the tool because I really think i need to collimate my 114 EQ scope. images seem washed out.
