I purchased my Losmandy GM-8 mount in 1997 in preparation for the Total Solar Eclipse of 1998. After my positive experience with the Losmandy G-11 mount, I wanted the smaller, lighter version for international travel. I've also used the GM-8 in South Africa and Bolivia. Of course, that was back when you could check two 70-pound bags on all the major airlines. With the current 50-pound limit per bag, it's no longer possible to take the GM-8 on international trips without paying an excess baggage fee.
The GM-8 is a solid, portable German equatorial mount that can easily carry a 30-pound load. With its folding tripod, it is perfect for car trips. The periodic error of the GM-8 Worm Gear typically about 20 arc-seconds peak-to-peak over an 8 minute cycle. This quite good for a portable mount.
New versions of the GM-8 are also available with GOTO options, but the original model serves me well and is great for car trips.
The table below contains the technical specifications on the Losmandy GM-8. For more information, see the Losmandy web site.
| SPECIFICATIONS OF GM-8 MOUNT | |
| R.A. Gear Wheel: | 2.8", 180 tooth 7075 T35 aluminum |
|---|---|
| DEC. Gear Wheel: | 2.8", 180 tooth 7075 T35 aluminum |
| DEC. and R.A. Worm gear: | 440C Stainless (54 Rockwell hardness) |
| Worm gear support: | Dual supported ball bearings |
| Worm gear coupling: | Oldham |
| Laser Engraved Setting Circles: | Porter Slip Ring design, 3.5" DEC. and R.A., |
| Right ascension resolution: | 6-minute increments, pointer |
| Declination circle resolution: | 2 degree increments, pointer |
| R.A. Axis Thrust Bearings: | one 2.1", one 2"; two 1.5" needle |
| DEC. Axis Needle Thrust Bearings: | one 2.1", one 2"; two 1.5" needle |
| DEC. and R.A. Clutches: | Slip clutch, variable friction, one knob ea. axis |
| Latitude Tangent Arm range: | 0-64 degrees with polar scope, lower latitude wedge available |
| Azimuth adjustment range: | +-8.5 degrees |
| Dovetail Saddle Plate: | Optional "C" or "D" Series |
| Weight of Mount Head | Approximately 17 lbs. |
| Weight of Field Tripod | Approximately 15 lbs. |
| Semi-Pier Tripod Height | 36" to 48" |
| Load Capacity: | Approximately 30 lbs. |