Jump to content


Photo

WO ZS 80mm - need focuser recommendations

  • Please log in to reply
15 replies to this topic

#1 LoveChina61

LoveChina61

    Viking 1

  • *****
  • Posts: 925
  • Joined: 19 Jun 2009

Posted 25 April 2013 - 09:50 AM

I have an older model ZS 80mm that I have mounted piggyback on my LX200. The ZS 80mm's long focusing tube just slides way out backwards when I point the scope towards the zenith. Luckily, there is a catch which prevents the focusing tube and camera from falling to the ground.

There is a small screw on the underside of the scope that adjusts the tube's sliding tension. I have tightened that small tension screw as much as tightly as possible but it just keeps happening.

Perhaps I can bore out the original tiny tension screw and then put a more heavy duty screw in its place? But then I would have to carefully weigh just how much to tighten it cause I don't want the focusing tube to continue sliding yet I also want to make sure the focusing tube has a little freeplay in it so that my Rigel focusing motor can still budge it along during its focusing routine.

What are some other options (besides getting an entirely new scope)? Have some of you been able to lock the focusing tube into place but then mount another adjustable focuser to the back of the refractor? If so, please let me know what 3rd party vendor focusers you are using with your refractors. Of course, whatever focuser I use needs to be strong enough to handle the weight of my SBIG 2000xcm without slipping even when I am pointed at the zenith.

Mike

#2 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5452
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 25 April 2013 - 09:52 AM

the trouble is an aftermarket focuser like a moonlite or feathertouch will cost as much as the ZS80.

on both of my WO scopes i was able to tighten down the tension screw tight enough to avoid slippage.

#3 GOLGO13

GOLGO13

    Gemini

  • *****
  • Posts: 3109
  • Joined: 05 Nov 2005
  • Loc: St. Louis area

Posted 25 April 2013 - 10:50 AM

Have you tightened the both screws...the one which you can tighten by hand and the one inside of it which requires a allen key?

If you have something really heavy in the focuser I can see it still moving on you...but otherwise that should keep it tight enough for most situations.

#4 LoveChina61

LoveChina61

    Viking 1

  • *****
  • Posts: 925
  • Joined: 19 Jun 2009

Posted 25 April 2013 - 10:55 AM

Did you really crank down the tension screw or did you have to keep playing around with it till you came up with the perfect tension level that was both strong enough to hold your camera in place yet loose enough so that you could easily adjust the focus knobs?

I hope it is not too finicky because I still must be able to use my electronic focuser while operating everything remotely.

#5 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 43872
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 25 April 2013 - 11:00 AM

Did you really crank down the tension screw or did you have to keep playing around with it till you came up with the perfect tension level that was both strong enough to hold your camera in place yet loose enough so that you could easily adjust the focus knobs?

I hope it is not too finicky because I still must be able to use my electronic focuser while operating everything remotely.


In my experience, these older WO focusers are finicky. A couple of questions:

- Do you actually use the two speed? If you have an electronic focuser, the two speed is probably not necessary. These work better as single speed focusers.

- Have you ever disassembled the focuser and cleaned the pinion shaft and the drawtube flat? These can get contaminated and they tend to slip.

Jon

#6 LoveChina61

LoveChina61

    Viking 1

  • *****
  • Posts: 925
  • Joined: 19 Jun 2009

Posted 25 April 2013 - 11:05 AM

If I tighten down the larger bolt by hand, will I still be able to operate the focuser remotely the next time I need to refocus?

#7 LoveChina61

LoveChina61

    Viking 1

  • *****
  • Posts: 925
  • Joined: 19 Jun 2009

Posted 25 April 2013 - 11:13 AM

John, my electronic focuser attaches to the larger focusing knob and only gives me one speed.

No, I have never taken apart the focuser. Is it hard to do? Can you point me to some detailed instructions on how to do it? I don't find much when doing a general internet search for this older model ZS 80mm.

#8 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 43872
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 25 April 2013 - 11:48 AM

John, my electronic focuser attaches to the larger focusing knob and only gives me one speed.

No, I have never taken apart the focuser. Is it hard to do? Can you point me to some detailed instructions on how to do it? I don't find much when doing a general internet search for this older model ZS 80mm.


I can't provide any detailed instructions, maybe someone else can. For me it's easy, now.. I can do it in my sleep.. :)

How heavy is the camera?

Also, where are you located? If you were close by, I could help.

Jon

#9 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5452
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 25 April 2013 - 07:31 PM

This page worked well enough for my WO's even though they aren't GSO's.

http://polluxchung.c...o_crayford_fix/

But that said.. I could never get things perfectly right when hanging a heavy load off my WO focusers (and I am not using an electronic focuser). My load was a QHY8, reducer, Meade DSI Pro, and off-axis guider. Not that big of a load. It would slip when close to vertical, and the focuser could not lift it (needed help).

At the end of the day you need a focuser upgrade. In my case rather than spend $400+ for a Feathertouch, I sold the scope for $400 and bought a used AT90EDT. Total cash out was about the same (around $400) and I got a triplet. The AT90EDT has a huge rack-and-pinion focuser which, while not as smooth as a Feathertouch, will never slip.

#10 LoveChina61

LoveChina61

    Viking 1

  • *****
  • Posts: 925
  • Joined: 19 Jun 2009

Posted 25 April 2013 - 07:40 PM

Jon, according to the specs the camera weighs just two pounds. It sure feels heavier than that in my hands, however. I would have estimated 4 pounds if I had not just referred to the camera's specification sheets.

Unfortunately, I am in the Phoenix area. You are in San Diego, right?

I still remember back in 1984 how San Diego's Grossmont College came up to face my teammates and I in the first ever "Ventura Bowl" football game. We were undefeated and finished about 14th in the nation that year, but Grossmont had a similar record. It was a back-n-forth battle the whole way...(blah, blah, blah)..... :)

Thanks again for all of your help, Jon.

P.S. you can probably guess who won the game or I wouldn't even have brought the topic up, right? ;)

#11 timmbottoni

timmbottoni

    Surveyor 1

  • -----
  • Posts: 1725
  • Joined: 25 Aug 2005
  • Loc: W Chicago suburbs, IL USA

Posted 25 April 2013 - 10:17 PM

Hi Mike,

William Yang also replied to your post on the WO Yahoo group, and he said you could buy a new R&P replacement which is probably the way to go.

Timm

#12 orlyandico

orlyandico

    Fly Me to the Moon

  • *****
  • Posts: 5452
  • Joined: 10 Aug 2009
  • Loc: Singapore

Posted 25 April 2013 - 11:56 PM

That's news. Last time I asked them they weren't selling the new 2" R&P from the ZS71 stand alone...

#13 timmbottoni

timmbottoni

    Surveyor 1

  • -----
  • Posts: 1725
  • Joined: 25 Aug 2005
  • Loc: W Chicago suburbs, IL USA

Posted 29 April 2013 - 08:53 AM

For others who might be interested William is going to offer the newest R&P focusers for purchase as replacements on older scopes.

The entire focuser unscrews which makes is a simple replacement done in minutes.

Cost will vary depending on the model and they aren't listed on the WO website yet so for now you will have to email William if you are interested.

Timm

#14 jrbarnett

jrbarnett

    Eyepiece Hooligan

  • *****
  • Posts: 20270
  • Joined: 28 Feb 2006
  • Loc: Petaluma, CA

Posted 29 April 2013 - 11:16 AM

I really like the new 2.5" Asian R&P focusers being offered by APM, Stellarvue and others. I wish someone in the "widget" business (such as a Scopestuff) would pick these up and then develop adapter rings for common refractors. I have one with the Stellarvue logo on it, on a Kunming 6" achromat, and it's no Fethertouch or Moonlite, but it is a country mile better than the GSO 2-speeds that are often the preferred low dollar focuser upgrade.

Regards,

Jim

#15 timmbottoni

timmbottoni

    Surveyor 1

  • -----
  • Posts: 1725
  • Joined: 25 Aug 2005
  • Loc: W Chicago suburbs, IL USA

Posted 29 April 2013 - 08:41 PM

Hi Jim, WO actually has offered their focusers for Synta and SCTs in the past, as well as upgrades for their own scopes, but I'm not sure what they are going to do with their new R&P focusers. They have both DDG and non-DDG models in production now, and these are their own design, unlike the ones from others. Not saying they are better or worse, since I don't have any others to compare to, but my 2.5" DDG on my GTF102 is very good, capable of easily lifting 10 lbs.

Enjoy!

Timm

#16 dscarpa

dscarpa

    Gemini

  • *****
  • Posts: 3006
  • Joined: 15 Mar 2008
  • Loc: San Diego Ca.

Posted 30 April 2013 - 10:25 AM

Both of my WO focusers a WO ZS-110 and a Crayford on my C9.25 are slowly giving up the ghost. At present the fine focus doesn't lift anything heavier than 12oz when pointed up more than 70* degrees. This only happens where all my eyepieces come to focus. Going to either side of it the fine focus lifts the load and nothing I've done adjustment wise makes any difference. My work around is to focus downward with the fine knob. I called Starlight to ask about SIPS and told Wayne about my issue with the WOs as well. He told me that WO is looking into putting FTs on some of their scopes. As for myself when I've recovered from the expense of my new newt a FT for the ZS is next on my list. I've got a OPT Crayford on my IM-715 and the 1.25" version on my Lunt 60. Neither is pretty nor very smooth but both lift without any problen using the fine focus even with a heavy load. David






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics