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Equipment Discussions >> Reflectors

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Jaimo!
Pooh-Bah
*****

Reged: 10/11/07

Loc: Exit 135 / 40° North
Re: Mega-mod thread for Zhumell dobs new [Re: Sarkikos]
      #5493943 - 10/29/12 12:26 AM

Quote:

I keep my Z8 secured on its Dob base in a corner of my bedroom upstairs. When I want to take it outside, first I unhook the OTA and rest it lengthwise on my bed. The OTA is always in one of three places: in its base, on the bed, or on the bench outside. I would never chance setting an OTA vertically on its own.

When I take my 10" to the dark site, it's in a large OTA bag. When I remove it from the bag, I immediately place it on the Dob mount. There's a lot of dew in our area, so I bring along a tarp that I can lay the OTA on at the end of the observing session, while I wipe the dew off with towels. Only then do I return the OTA to the bag in my vehicle. The idea never crossed my mind to rest any OTA vertically unless it's in the Dob mount. Not something I'd ever do.

Mike





Why would you not rest an OTA vertically?

Jaimo!


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BSJ
Pooh-Bah
*****

Reged: 12/22/08

Loc: Grand Isle, VT
Re: Mega-mod thread for Zhumell dobs new [Re: Jaimo!]
      #5494170 - 10/29/12 07:24 AM





Why would you not rest an OTA vertically?
Jaimo!




Cause nobody is going to yell TIMBER, to warn you when it starts to fall over!


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Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Suburban Maryland, USA
Re: Mega-mod thread for Zhumell dobs new [Re: BSJ]
      #5494291 - 10/29/12 09:31 AM

Exactly! Resting the OTA vertically is inherently the most unstable position ... unless it's in the Dob base.

My advice: buy a bench for your yard and lay the OTA on the bench. Benches usually have a curved seat that will prevent the OTA from rolling off onto the ground. What's going to prevent the OTA from falling when resting vertically? Three little pegs?

At my dark site, I set up on grass. That is the best area to set up due to thermal properties. I would never rest an OTA vertically on grass. Not very stable.

Even inside my house, most areas are covered with plush carpet, not a very good surface for resting an OTA on-end.

YMMV

Mike


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Jaimo!
Pooh-Bah
*****

Reged: 10/11/07

Loc: Exit 135 / 40° North
Re: Mega-mod thread for Zhumell dobs new [Re: Sarkikos]
      #5494689 - 10/29/12 01:51 PM

Quote:

Exactly! Resting the OTA vertically is inherently the most unstable position ... unless it's in the Dob base.

My advice: buy a bench for your yard and lay the OTA on the bench. Benches usually have a curved seat that will prevent the OTA from rolling off onto the ground. What's going to prevent the OTA from falling when resting vertically? Three little pegs?

At my dark site, I set up on grass. That is the best area to set up due to thermal properties. I would never rest an OTA vertically on grass. Not very stable.

Even inside my house, most areas are covered with plush carpet, not a very good surface for resting an OTA on-end.

YMMV

Mike




Sorry Mike,

I think we will have to agree to disagree. The 3 little pegs work fine for my purposes, especially as a majority of mass of the OTA is concentrated closer to the ground, there is little chance of it just falling over. I have once placed a Z8 OTA horizontally on the tailgate of my truck, similar to your bench, and I was scared it could roll and slip off... When taking the scope outside, I will remove it from the base and set it on the stable concrete floor of my basement. I then walk the base outside and return for the OTA. I find the easiest way to manage the OTA is in the vertical position, both in the carrying up the stairs and the subsequent placement into the mount, I would fear dropping the tube while moving the tube from vertical to horizontal a few time while transporting.

To each his own, find out what works for you and do it. I also set up in the grass as I feel not only for the thermal properties but for the shock absorbing properties as well, it's not as devastating when you drop an eyepiece onto the dew covered sod, rather than the driveway.

Jaimo!


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bob irvin
sage


Reged: 03/22/11

Loc: Greater Los Angeles, CA
Re: Mega-mod thread for Zhumell dobs new [Re: Jaimo!]
      #5494939 - 10/29/12 04:32 PM

Great idea, thanks for the post. I may well give this a try on my Z10.; after I fix the back door (for my wife)



bob


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bob irvin
sage


Reged: 03/22/11

Loc: Greater Los Angeles, CA
Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5495005 - 10/29/12 05:14 PM Attachment (89 downloads)

Here's a transport/storage box I made for my Z10. I used the dimensions from the original packing box and the foam that was used in shipping. The wheels make it easy to move around and for storage I have a weather seal around the lid to keep dust out. Note the base can be strapped on top for easy moving of the whole scope around.

Great Thread, by the way.

bob

Edited by bob irvin (10/29/12 05:15 PM)


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tag1260
scholastic sledgehammer
*****

Reged: 10/07/12

Loc: Ohio, USA
Re: Mega-mod thread for Zhumell dobs new [Re: bob irvin]
      #5495011 - 10/29/12 05:18 PM

Hey Bob,

Guess who's gonna steal your idea for transport!!!

Edited by tag1260 (10/29/12 05:19 PM)


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Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Suburban Maryland, USA
Re: Mega-mod thread for Zhumell dobs new [Re: tag1260]
      #5495034 - 10/29/12 05:29 PM

That would not work for me. No way to get something like that down the stairs and off the porch!

Here is what I use to carry my 10" f/4.8 OTA out of my house and into my vehicle to travel to the dark site:

47"x17"x18" Orion Padded Telescope Case

But I don't remember it costing that much when I bought mine five years ago.

If I'm going to set up the 10" by my house I just carry out the OTA in my arms. No big deal.


Mike


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gene williams
member
*****

Reged: 01/17/11

Loc: Missouri
Re: Mega-mod thread for Zhumell dobs new [Re: Sarkikos]
      #5495372 - 10/29/12 09:44 PM

yes, Mike I had a Z8 many years ago. At F6 I wouldn't set it up vertically either. I imagine it would tip over pretty easily. The Z10 and Z12 are F4.9 and very stable in the vertical position. I can literally tip it a good twenty degrees from vertical while it is upright, and when I let go it assumes its upright position. The mirror at the bottom represents most of the weight.

It's also very, very hard on a persons back once you get into the Z10 and Z12 size. The Z8 is really easy compared to these beasts. Anything a person can do to make the lifting easier just makes it that much more enjoyable to use the scope. Doing the bearhug on the Z10 and letting it gently lower to the floor is very satisfying, easy, and natural.


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fnowat
member
*****

Reged: 06/12/12

Loc: N.E. Illinois (Chicago suburbs...
Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5526467 - 11/18/12 04:55 PM Attachment (42 downloads)

Quote:

When I decided to replace my 60mm refractor with a larger dob, I turned to the internet to compare scopes. That was how I discovered the Zhumell line. And further searching on Google turned up this thread called "New Zhumell owners upgrade mega list thread." That was my introduction to Cloudy Nights.

Once I got a Z10, I returned to that thread over and over for help and new ideas for improvements to make. Since that thread is now in the archives, and the Zhumell line has gone through some changes since then (different alt and az bearings), I thought it would be a good idea to collect suggestions and links people have that will help new Z owners get the most out of their scopes.

So, here are the mods I'll start us off with:

    Improvements for secondary mirror adjustment
  • Change the screws! Why? Using a screwdriver is a hassle, and has the potential of being dropped down the tube. Many people use Bob's Knobs, which have large plastic heads on them. I used allen-wrench screws, which have a barrel on the end that can be tightened with the fingers. These can be found cheap at the local hardware store.

  • Insert a washer (or two!). Jason D brought this great idea up in this post in the "squirrely secondary mirror adjustments" thread (the thread is a great read by itself). The basic idea is to cut out a washer out of a plastic milk jug to make rotating your secondary easier and allow adjustment of just one screw without having to also tweak the other two. I believe Jason now advocates stacking two of these washers together for greater improvement.

    Improve your laser
    Getting a laser with your scope--how cool is that! But, here's how to make it better...
  • Collimate your laser. Someone please locate a good thread for this with pictures! The adjustments aren't too hard, once you understand what you're trying to do. Use a jig, or two sets of nails in "V" formation in a block, or anything else that lets you rotate the laser freely while pointing at a paper taped to the wall. Use the three tiny allen screws at the back of the laser to adjust the beam until it rotates without inscribing a circle.

  • Add an aperture stop to your laser. Described in good detail in this thread. You can get your laser down to a dot instead of a "bar" (making it easier to collimate, and collimate with). You'll get diffraction rings that will cast a shadow of your primary donut back onto the target face of the laser for more accurate collimation (using a barlow is even better).

    Optical improvements
  • Flocking! There are lots of threads and articles on CN on how to do it. I went with a black velvet from Joanne Fabrics since it was highly rated in this test. You can choose to flock a little or a lot, but I went with the whole tube--turns it into a nice black hole for light to get sucked into!

  • Blacken all the mirror edges and shiny parts. Use a sharpie to darken all reflective edges and surfaces. Be VERY CAREFUL around the mirrors!

  • Check the primary mirror clips. They might be too tight. Back them off until there's a slight gap (enough to slide a business card in) to avoid "pinching" the optics.

  • Check your center spot. It might be accurate, then again, it might not. Mine was off a couple millimeters. Catseye tools has a template you can use to put a new spot in place, or you can make your own template.

  • Change your primary springs? Many people do. You can find stiffer ones at a local hardware store. I replaced mine, but then went back to the originals so I could get the mirror closer to the bottom of the tube.

  • Add a dew/light shield. I made mine out of a long strip of felt 3.5' long by 9" wide. I glued three 9x11" pieces of craft foam to one side, leaving about 1/4" between the pieces. I added velcro tabs to the ends, and now I have a cover I can wrap around the end of the tube. The foam gives it rigidity, it rests against the secondary holder screws, and it can be folded up for storage.

  • Dew/lightshields for your finderscope. For this, I cut a piece of craft foam in half, and added velcro to make a simple wrap for the end of my finderscope. Not pretty, but functional. I also made a small "sleeve" of black felt that sits around the eyepiece end of the finder. In dewy conditions, I can raise the sleeve to give some protection to the eyepiece. Easier than putting the cap on and off.

    Other additions
  • Add a Rigel Quikfinder or Telrad. Telrad seems to have the market share around here, but I went with a Rigel, because it fits perfectly between the focuser and the finderscope! Either one of these tools will be a benefit to your star-hopping.

  • Rotate your focuser. Why? In its stock position, the focus knobs are never horizontal unless you're looking at the horizon. Got this idea from Don Pensack: There are two tiny grub screws on the side of the focuser base--one toward the mirror, one toward the tube opening. Loosen them, and rotate the focuser 45° so that the focus knobs are level when the scope points at 45°. This mod's more of a personal preference, but I think it makes the scope more comfortable to use.

  • Improve your airflow. Adding a baffle to the back of the tube will direct more air up the pipe. Check out this sample posted by Hudson Yak.

  • Keep all things in balance... The adjustable hubs are a great "coarse adjustment" for balance, but a counterweight also helps. Numerous threads on this topic, but I recommend a heavy magnet like this bad boy. I wrapped mine in felt to protect the tube, added a little duct tape for friction, and put it on the belly just below the hubs, on the side opposite the focuser. When changing to different weight EPs, I just push the weight up or down the tube a bit. This saves the rubber in your alt brakes for light duty work only, and makes the motion smoother without the "bounce back" if the brakes are too tight.

  • Get a shower cap--to seal the bottom of the tube against spiders, etc., when stored. Very cheap, can be found anywhere.

  • Align your finderscope crosshairs. Somehow, for me it's just easier if the up-down and side-to-side motion of the scope corresponds to the crosshairs in the finderscope. You can change the orientation of the hairs by rotating the finder in the holder, or if you're adventurous, you can unscrew the EP and CAREFULLY rotate the ring the crosshairs are in.


So, what mods have you made? Feel free to add to this list, or include some links to help illustrate mods already mentioned. I hope this will be a help to others like the original thread helped me!




Thank you for the lead/link to cool mods for our "Z" telescopes! Here in the gap between the Midwest and the Northeast it is way-too often cold and cloudy. The Mrs and I did a simple thing, we gave our Dob 'pajamas' (aka-sweat pants) just to lessen the frost build-up. We leave the fan on under her to keep the mirror ambient.


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fnowat
member
*****

Reged: 06/12/12

Loc: N.E. Illinois (Chicago suburbs...
Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5526474 - 11/18/12 04:56 PM

Forgot- love it, love it, love it...

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Sarkikos
Postmaster
*****

Reged: 12/18/07

Loc: Suburban Maryland, USA
Re: Mega-mod thread for Zhumell dobs new [Re: fnowat]
      #5526681 - 11/18/12 07:32 PM

fnowat,

Judging from your picture, I see one obvious upgrade for your Z Dob: a chair to sit in! You'll hurt your back bending over like that.

Don't stand when you can sit, don't sit when you can lie. - Old Civil Servant Saying


Mike


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fnowat
member
*****

Reged: 06/12/12

Loc: N.E. Illinois (Chicago suburbs...
Re: Mega-mod thread for Zhumell dobs new [Re: Sarkikos]
      #5529176 - 11/20/12 12:05 AM

LOL
Thanks Mike, that is on my Christmas list. And in the trunk of the care there ia a little 3-legged chair/stool which is only about 14" tall.


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Tim L
Carpal Tunnel
*****

Reged: 12/17/08

Loc: Missouri
Re: Mega-mod thread for Zhumell dobs new [Re: fnowat]
      #5530528 - 11/20/12 04:06 PM

Quote:

Thank you for the lead/link to cool mods for our "Z" telescopes! Here in the gap between the Midwest and the Northeast it is way-too often cold and cloudy. The Mrs and I did a simple thing, we gave our Dob 'pajamas' (aka-sweat pants) just to lessen the frost build-up. We leave the fan on under her to keep the mirror ambient.




I like the idea! Is it really just a pair of sweat pants big enough for the tube or did you use some other material?


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csrlice12
Postmaster
*****

Reged: 05/22/12

Loc: Denver, CO
Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5530595 - 11/20/12 04:39 PM

+1 on a laser to collimate your scope; but I recommend a Howie Glatter laser. That way you don't have to worry about collimating your collimater. Howie glatter lasers stay collimated unless you drop it while skydiving...Sometimes a quality product just can't be beat.

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fnowat
member
*****

Reged: 06/12/12

Loc: N.E. Illinois (Chicago suburbs...
Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5561494 - 12/08/12 08:57 PM

Quote:

Quote:

Thank you for the lead/link to cool mods for our "Z" telescopes! Here in the gap between the Midwest and the Northeast it is way-too often cold and cloudy. The Mrs and I did a simple thing, we gave our Dob 'pajamas' (aka-sweat pants) just to lessen the frost build-up. We leave the fan on under her to keep the mirror ambient.




I like the idea! Is it really just a pair of sweat pants big enough for the tube or did you use some other material?




Sorry Tim, It was just a pair of xxxl sweat pants and then ripped out the seam. The pull string waist band is on the bottom, and the pockets hold my 4 "AAA" battery pack (also helps balance when using larger TV ep/s. Cut the rubber band on the ankle/bottoms and then tied each leg together and it is positioned above the thumb screws (spider vane screw) for preventing slipping down on the tube. I often have to guide the pants off of the bearings when setting the OTA onto the bearings. Total cost $1.99 from Goodwill/Salvation Army thrift store. Not pretty department store look...but it is dark when she is wearing


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kfiscus
Carpal Tunnel
*****

Reged: 07/09/12

Loc: Albert Lea, MN, USA
Re: Mega-mod thread for Zhumell dobs new [Re: fnowat]
      #5561796 - 12/09/12 01:41 AM Attachment (83 downloads)

Bought a new-to-me Z12 and had the seller ship it to me without the HEAVY particle board mount. I had him strip every part off the mount and send the parts. I used my buddy's stock Z12 base's parts as my patterns and then built my shorter, lighter, and prettier base. I needed to get rid of the stock mount's extra height because I'm only 5'8" and the scope rides on a dedicated Atomic EQ platform (no groundboard at all). The EP is right at my eye at the zenith.

Other mods done by me or previous owner: Refigured primary(OMI), premium slightly-smaller secondary, Telrad & dew shield at top of tube- right by focuser, straight 8x50 finder adjacent to telrad. Fully-flocked tube.
Next big mod: Astrocrumb original(?) filter slide and rotated spider.

Edited by kfiscus (12/09/12 01:52 AM)


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Tim L
Carpal Tunnel
*****

Reged: 12/17/08

Loc: Missouri
Re: Mega-mod thread for Zhumell dobs new [Re: kfiscus]
      #5563932 - 12/10/12 10:54 AM

kfiscus,

Wow--I love that front panel!


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pftarch
professor emeritus


Reged: 09/21/07

Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5564204 - 12/10/12 01:36 PM

That base DEFINITELY fall into the "way cool" category. Beautiful job.

Peter T.


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echoes1961
member


Reged: 09/14/12

Re: Mega-mod thread for Zhumell dobs new [Re: Tim L]
      #5564297 - 12/10/12 02:42 PM

If you want more freedom adjusting the focuser. I removed the 4 focuser screw & nuts and the focuser on my Z10. Then I took a 1/4" drill and carefully "slotted" the holes up and down (top to bottom) thereby giving the focuser freedom to be moved slightly up or down the tube, whatever the adjustment called for.

I did this because I could never get the final collamation right and it seemed that the whole focuser needed to be moved a little towards the primary mirror. And it worked in my case.


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