Explore Scientific Rack and Pinion Focuser Adjustments

A very BASIS instruction on how to adjust and control your Explore Scientific Rack and Pinion Focuser on the newer 80mm ED APO Essential Series refractor, 102mm ED APO Essential and Carbon Fiber refractor, 127mm ED APO Essential and Carbon Fiber refractor and the 152mm ED APO Carbon Fiber refractor.

[jonholt]

This helped me so much. My focusser kept slipping and I thought it was missing a part! Nope! After watching this, I tighened the hex screws and it now works like new.

[JohnReadAuthor]

I have four of these telescopes (two carbon fibre and two white-tube), and the one thing that is consistent between them is that when they arrive from the factory the micro focus knob is not activated (it spins freely on all four telescopes). This video seems to be missing that part of the setup which is how to engage the fine focus mechanism.

[charvey]

Ahh finally I know what the central knob on top is for... rotating the focuser. Thank you! I wish there was a manual for my hexa foc focuser (if there is I couldn’t find it).

[juanma]

Great video. Explore Scientific should be doing more of them for their community. The included instructions with the ED CF 127 telescope are by far not enough and there is a lot of room for improvement.

[AMadScientist]

My course knob on the right started to just spin freely. Although you didn't cover it here, I was able to see a tiny hole for a hex. There is a tiny hex screw in there. I tighten it and it works perfectly.

[nelsonrivera]

Great video, i even found out stuff nobody posted before about focus adjustment , thank you

[ACEOFSPACE]

Thanks for the info I just bought my ED102 fcd 100 on jan 9 2019 can't wait to use it. i'm a Celestron guy have two celestron scopes Edge Hd 800 and C9.25 XLT.Bought this scope for wide field Astrophotography.I like the scope so far the build quality and focuser are Excellent.
Explore Scientific

[kennethshaw]

I have the Essential Series 127mm ED refractor purchased in 2016 with this type of R and P focuser. The three Allen head grub screws constantly get loose and causes significant play in the body of the focuser. I've carefully adjusted and tightened them numerous times. During a viewing or an AP session, it is unavoidable to not overly tighten the single thumbscrew that locks the focuser in place when the Allen screws loosen and the focuser wobbles. As indicated over tightening the thumbscrew causes a permanent dent in the metal ring where it makes contact. This occurs over and over and results in multiple rough spots causing the rotation to be very rough. Tightening this thumbscrew is the only reliable option to keep the focuser from having play. Ironically, this thumbscrew does not have a nylon tip so it's metal on metal. Watch the video at 5:59 to 6:03 seconds to see this play and wobble in the video. I spoke to an ES representative at NEAF 2017 and the only advice was to keep the Allen screws adjusted and to not overtighten the thumb screw. There are numerous forum comments on Cloudy Nights about users who dislike these focusers and seek to change them. This is a design flaw that degrades an otherwise excellent scope.

[Justoneoftheguys]

Great video. How do you adjust the micro focuser when it has too much play?

[fatboy]

I need to stop overtightening things... Life long bad habit! I have some grittiness going on so I'm going to try out taking that block off and seeing if I can get it cleaned. Great video, thanks!

[rodsmolter]

Good informative video. My ED 127 won't come to focus so I'll try adding and extension tube to the focuser.

[jinzai]

I just ordered my ED80CF, field flattener and case. My first astrograph.

[NMagturo]

Hi there. How would you adjust the ES ED 80 CF? Is it with the two hex screws just "below" the focus release thumb screw?

[boyanpungov]

I installed a zwo eaf and since then I can't get it to work like it was :(
When focuser goes in, it moves smoothly, when backing up it moves hardly and the 1:10 knob stopped working for some odd reason. It looks really easy thing to do, but for some reason it turned out to be a pandora's box for me. :(((

[markc]

Thank you for the video. I have an ED 80 and ED 127. I enjoy them. However the eyepiece clamp can be a problem when I try insert the 2” diagonal or camera. Does a Baader clicklock fit the focuser by screwing on the focuser just as an extension tube to replace the eyepiece clamp?

[YTMegiddo]

Doh! Unscrewing the holder for extensions - ESRPEXT2. I've been struggling with finding the right extensions to achieve focus with my Flattener/CCD. Oh and be careful, the rack and pinion can fall out! (don't ask how I know)

[vicamaral]

Just replaced the 3 helen screws with the NYLON TIPS, CAUSE OLD 1 WERE CHEAP AND NYLON TIPS FELL OFF, AND I DRILLED 2 MORE HOLES L AND RIGHT BOTTOM FOR EXTRA SUPPORT AND SLIDING WITH VERY LITTLE GREASE, NOW I NEED TO WORK ON THE PLASTIC BUSHING REPLACE WITH TEFLON. WORLD CHEAPEST FOCUSER FROM DAY 1, FOCUSER WOULDNT EVEN ROTATE ALL 3 CRUB SCREWS WERE TO TIGHT, IF THE TUPE COMES OUT MORE THEN 15MM TRAVEL THE TUPE WOBBLES, ON AN 3.000 DOLLER SCOPE, CARBAGE, were can i bye an replacement they have an hex 2.5 inch replacement put not in stock backorder

[Astro-George]

What size allen head do you use for the focus knobs? I am needing the diameter of the collar under the large\course knob so I can fit an autofocus motor.

[davidbrandenburg]

who makes the focuser for those explore scientific telescopes?

[ronkramer]

mine I think is older. It has no rotating screw and has no focus tension - other than two thumb screws on the bottom - but they don't do anything. If anything, it seems looser if they are tightened? I contacted chat on your website and someone said they would email me the adjustments to be made. and recieved nothing.