Jump to content


DEC worm wheel location?

  • Please log in to reply
4 replies to this topic

#1 Space99


    Mariner 2

  • -----
  • Posts: 220
  • Joined: 14 Aug 2008

Posted 17 May 2011 - 05:05 AM

Hi everyone,
my question is, way the pro EQ-mounts (AP, MI, PM) has the
DEC worm wheel at the 'north' of the shaft?
Logic dictate it should be on the 'south' to reduce counter-weight.
What am I missing?
I'm in the agony to decide between
Germ vs Fork for my ATM EQ mount, and if it's a Germ. then
where the worm should be located.


#2 jmiele


    Patron Saint?

  • *****
  • Posts: 4331
  • Joined: 04 Dec 2010

Posted 17 May 2011 - 08:04 AM

Forks are def easier to view from. As to locating the DEC worm on a GEM, I'm going to have to side with the engineers :) I'm thinking if it belonged in the south, Roland and the rest would have it there. :)


#3 Eddgie


    Voyager 1

  • *****
  • Posts: 13672
  • Joined: 01 Feb 2006

Posted 17 May 2011 - 10:00 PM

The reason that the dec worm is usually located at the top of the housing is because to put it under the dec housing would require that the RA shaft extend out further so the wheel dec worm could clear the RA housing.

Most mounts made these days put the Dec worm wheel at the top of the dec housing.

#4 Space99


    Mariner 2

  • -----
  • Posts: 220
  • Joined: 14 Aug 2008

Posted 18 May 2011 - 03:44 AM

You right Eddgie.

Thanks guys,


#5 Geo.



  • *****
  • Posts: 3144
  • Joined: 01 Oct 2008
  • Loc: Upstate NY

Posted 18 May 2011 - 09:15 PM

I've read that having the worm wheel closer to the tube is a better design. Something to do with torsional effect along the axle. But putting the gears at the lower end was common in the day. I've seen problems with the clutching mechanisms stressing the axle keepers as the tension wants to pull the whole thing out the bottom.

Meade made some EQ (MTS) forks that didn't sell all that well but were a nice concept.

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics