APM GE-300 (Worm Gear)

Our professional APM GE-300 mounting starts at a point where the carrying capacity of other mountings is too low. This mount has been developed for large Cassegrain telescopes and Hypergraphs from 24" aperture onwards, but it is also a perfect match for long and heavy refractors like our large APM-LZOS apochromatic refractors. Hollow shafts with a inner diameter of 90mm and a outer diameter of 140mm provide a very high carrying capacity of 660 lb. If requested, the mount is also available in a complete stainless steel version.

The APM GE-300 is available in two variants depending on the field of application, here:

Worm Gear model

This version of the APM GE-300 is equipped with high precision wormwheels with 350mm diameter. Very interesting are the extremely smoothly adjustable friction clutches, which you can easily handle with a small grip.

The wormgear drive has its strengths when using multiple telescope setups with different balances (e.g. often change the optical equipment like eyepieces and cameras at the rear of the telescope). So this version type of our biggest mount is perfectly suitable for public observatories.

In the basic configuration you will get this mount either with:

Technical data:

MaterialSteel / Stainless Steel
Type of mountParallactic GOTO mount
Motor controlSiTech Control
MotorsServo Motors
Weight equatorial head990 lb without Counterweights
Length / Width / Height1209mm / 370mm / 1112mm
Payload max.660 lb Photographic / 880 lb Visual
(depending on using and demand)
Polar hight adjustment0 - 90°
Telescope attachmentOptional
Diameter of Gear /
Number of Tooth
Material wormwheelBronze
Periodic error+/- 3 Arc Seconds RMS
Counterweights3 x 88 lb inclusive
TripodEquatorial Pier
Weight over allca. 1255 lb

Mounting Blueprints

Observatory installation example with 12" F/12 LZOS Apochromat

Configuration and Shipping

  • Equatorial Head incl. 3 Counterweights á 88 lb
  • Wormgears 2 Pc.
  • Motors and Controllers as described above
  • Power Supply
  • Delivery time is 9 to 12 months

Equatorial pier

The GE-300 can be configured as an equatorial pier version with 1,5m height. All other features are identical to the regular GE-300 mounting, except a more heavy weight.

Equatorial Pier Mounting Blueprints

Fork version

The GE-300 can be configured as a fork version. All other features are identical to the regular GE-300 mounting, except a more heavy weight. The fork width can be adapted to the telescope of the customer.

Fork installation example with 24" F/8 Ritchey Chrétien

Prices on www.apm-telescopes.de!