How to Teach an Old DOB New Tricks

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Bryan Stone, MD, PhD, NSAAC President

Bryan Stone, MD, PhD, NSAAC President

EconoDobs

Asian Dobs, aka “EconoDobs” include Synta (Orion, Skywatcherm Buschnell, from China and GSO (Zhumell, Apetura, AstroTech, Lightbridge, DBA and X-Class, from Taiwan

How they do out of the box:  Usually pretty good optics but hit or miss

  • Low price and good value, bang for the buck
  • Included eyepieces, crayford focusers and finder scopes are OK but not the best.
  • Metal tubes are good and bad…allow use of magnets for balance, but scratch and ding prone.

These EconoDobs are often available used on Astromart or CloudyNights Classifieds.

Shortcomings of EconoDobs:

  • Some have poor optics….luck of the draw
  • Collimation adjustments are difficult especially secondary mirror
  • Balancing issues arise when you add aftermarket finderscopes or heavy eyepieces
  • Motions are not as smooth as premium Dobs
  • low quality hadrware/screws
  • Particleboard bases “fallaparticleboard” are heavy, and prone to water damage.
  • Lateral slip in the rocker box
  • Fast f/ratios demand expensive wide field eyepieces or stick with 50 degree plossls or orthoscopics
  • Navigation knob no longer included standard

Hacks can address many of these shortcomings and make EconoDobs more fun and earier to use because they work better!!!

Hack #1   Mirror Collimation aids

  • Fender washer to prevent divots in secondary holder $0.50 at any hardware store
  • Large Allen Screwdriver $3-4
  • Bob’s Knobs    www.bobsknobs.com  to replace Allen screws and allow no-tool secondary mirror adjustment

Hack #2  Balance

American Science and Surplus makes 1/2 pound donut magnets $3.75 each, compared to $12 at Scopestuff.  Item 2823P1 www.sciplus.com   Line them with felt from Jackson Fabrics or AC Moore, $2

Hack #3  Smoothness of Motions

  • Azimuth motion can be improved for free with milk jug washers or CD’s between ground board and rocker box
  • Scope stuff makes Dob kits with ebony star rings  www.scopestuff.com
  • Or upgrade to a premium aftermarket Dob mount like GoldenEye (Hack #5)

Hack #4 Hardware upgrade

The screws that hold the primary mirror cell strip easily.  Replace with stainless steel screws from Home Dpeot or Lowes 4mm x 6mm Dr # 313  $2-3

Hack #5 Particleboard base upgrades to baltic birch to reduce weight and get smoother motions and improve longevity all at once

Or do-it-yourself using original particleboard as templates and get ebonystar and real virgin teflon at scopestuff or Astrosystems

Hack #6  Prevent lateral slip

Install bumpers on the insides of the rocker box.  Self adhesive felt furniture glides or 1/8 inch thick teflon squares with scotch mounting squares

Hack #7  Get better eyepieces to improve the view. 

Talk to Bryan about this.  He will give you individual advice based on your needs and budget.

Hack #8  add a navigation knob

Hack #9  Cosmetic touchups for battle scars

  • cafepress.com stickers $$$$  best on flat surfaces
  • Powered by Televue sticker:  free with Televue eyepieces
  • Astronomical League 3 inch diameter sticker $0.25
  • Many free stickers are given at NEAF
  • Sharpie
  • black auto touchup paint

Hack #10  Flocking to enhance contrast

Hack #11  handle straps  

John Hobbs and the Millers found these for only $7.29 at Amazon.com     Velcrovel Strap item # 90482

Hack #12    Finder upgrades

  • Telrad has more support than Rigel quickfinder.
  • Telrad from scopestuff or Amazon
  • Quickfinder from www.rigelsys.com

Hack #13  Focuser upgrades

Ron at www.focuser.com makes the Moonlite which is expensive but wonderful.

Hack #14  inexpensive computerized locating

  • computer gives alt and az cordinates.  Planetarium software for palm pilot www.aho.ch/palmplanets/
  • you need an inclinometer, analog from home depot for $8 or digital from Amazon.com, $30
  • This really works….we found Saturn in broad daylight using this hack.

Hack #15  Optics upgrades

This can be expensive but many of us have had mirrors refigured with great results.  First step is to buy book on star testing by Suitor.     Refigurers include Owl, Swayze and Waite among others.

Do you have a hack to teach an old EconoDob new tricks?  Share it!

Clear skies,
Bryan Stone, MD, PhD
President, NSAAC

One Response to “How to Teach an Old DOB New Tricks”

  1. Kandy says:

    For inexpensive computerized locating, consider SkEye for Android devices – http://lavadip.com/skeye/. It gives you push-to directions (like the Orion Intelliscopes). The challenge is to mount your smartphone firmly to the optical tube.


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