Jump to content


Deforking an ETX125

  • Please log in to reply
4 replies to this topic

#1 highertheflyer


    Viking 1

  • *****
  • Posts: 724
  • Joined: 08 Jul 2005
  • Loc: Aledo, Texas

Posted 01 May 2013 - 09:54 PM

I've deforked an ETX90 following Weasners suggestions ande was thinking of doing the same with the ETX125.
Has anyone attempted this and is it possible to remove the OPA (and replace) back into the mount with little trouble?
Wanting to use the ETX125 OTA with another mount for star parties.

#2 cuivienor


    Viking 1

  • -----
  • Posts: 665
  • Joined: 06 Oct 2010
  • Loc: Tokyo, Japan

Posted 02 May 2013 - 12:27 AM


I've deforked and re-forked my ETX125 many times to make improvements in the motor mechanism. I've done the same for the ETX90. The system is exactly the same, but the ETX125 is much heavier, so it is more difficult to handle (you feel much more like carrying a baby and trying not to drop her).

- remove the screws on the sidearms (two per arm).
- put one hand under the tube. Never remove that hand. Always keep a bit of strength in that hand.
- try to slightly spread the arms while pushing the tube out of the mount (push the tube towards the front out of the arms of the mount)
- it will come off

Reforking is the reverse, but it is in my experience much more difficult to get the arms to click back onto the tube.



#3 highertheflyer


    Viking 1

  • *****
  • Posts: 724
  • Joined: 08 Jul 2005
  • Loc: Aledo, Texas

Posted 02 May 2013 - 10:08 PM

Thanks Yannick.
I thought they might be similar but needed some encouragement from one who has deforked and reforked that 125.

#4 Geo.



  • *****
  • Posts: 3132
  • Joined: 01 Oct 2008
  • Loc: Upstate NY

Posted 03 May 2013 - 11:39 AM

If you have the alloy forks they can't be spread so all the streaching has to be done by the trunion arms. Pretty sure you can get at the fork arm retaining screws through the inside of the base. Loosening them will make the whole process easier.

#5 Fish


    Viking 1

  • *****
  • Posts: 659
  • Joined: 13 Oct 2007
  • Loc: Norridgewock, ME

Posted 03 May 2013 - 05:24 PM


HINT: If you do defork the ETX-125 I recommend tube rings over using the built-in screw holes on the underside.

Those holes are nothing but inserts into a plastic base. They will either fail as mine did - I was lucky to catch it before gravity took it away - or give you way too much flexure with a dovetail.

Yes, a set of rings for that size OTA are hard to find but I believe it's the only practical way to do it.

Regards, Marc

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics