Jump to content


Photo

Fine tuning Tak EM200

  • Please log in to reply
4 replies to this topic

#1 lernerda

lernerda

    Viking 1

  • -----
  • Posts: 589
  • Joined: 21 Jan 2007
  • Loc: New Jersey 40.0 N 74.9 W

Posted 07 July 2009 - 02:09 PM

I recently aquired a tak EM200 from a member of my local group.

Two things I noticed:

1) On the altitude lockdown, it doesn't matter how much I tighten the lever, the mount will still move up and down (as seen in the polar scope) when I turn the altitude adjustment key. Is this normal?

2) On azimuth, sometimes when doing a precision polar alignment, (using WCS alignment software), the star shifts to the west as I begin move in that direction, then as I continue to turn azimuth knob, the image begins to go back in the correct direction. Also I noticed there are little indentations on the azimuth peg on the tripod (I am assuming these are from tighting the azimuth screws). Should I loosen the azimuth peg, and rotate it 90 deg or should I leave wellenough alone? (although the "southern" post hole on the tripod is completly round it is doesn't look like there is a way to set the peg perfectly "square" with the northern leg of the tripod.

last thing. Once I get azimuth precisly polar aligned, should tighten both azimnuth knobs against the post, or leave a litte gap and just tighten the mounting bolt (underneath tripod)?

#2 revans

revans

    Surveyor 1

  • *****
  • Posts: 1653
  • Joined: 26 Sep 2005
  • Loc: Fitchburg, MA

Posted 07 July 2009 - 02:29 PM

I've used an Em-200 for a couple of years now. I think your mount is acting normally. I would leave well enough alone. I don't know anything about the precision software you are using. I am just a lunar/planetary person and the basic Tak alignment procedure has always been enough for me.

Rick

#3 Dennis_Oz

Dennis_Oz

    Ranger 4

  • -----
  • Posts: 335
  • Joined: 20 Aug 2006
  • Loc: Brisbane, Australia

Posted 07 July 2009 - 04:04 PM

I think that the lock down mechanism is more of a clutch than a hard lock system, so like you, I can also adjust the altitude despite the lock down being fully applied.

Cheers

Dennis

#4 johnnyha

johnnyha

    Fly Me to the Moon

  • *****
  • Posts: 6500
  • Joined: 12 Nov 2006
  • Loc: Sherman Oaks, CA

Posted 07 July 2009 - 08:41 PM

Once you get the az aligned I would tighten both bolts down. I actually tighten the main (underneath) mounting bolt first now because I find everything shifts if I don't, I'm not having any issues with that. As Dennis said the alt knob is a clutch. Most of the fine adjustments can be done with the lockdowns and knobs all tightened.

#5 Jaxdialation

Jaxdialation

    Gemini

  • *****
  • Posts: 3197
  • Joined: 01 Apr 2007
  • Loc: Northeast, FL

Posted 07 July 2009 - 10:40 PM

I never tightened anything but the clutches on my 200 or 400.
Work fine for 30 minute exposures for me.

Can't help you with WCS since I use PAM, but not all the time.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics