10Micron GM2000 HPS II COMBI
10Micron is an Italian company that is 100% focused on making high-end telescope mounts. From small mounts used by amateurs to large mounts used in professional observatories. The GM2000HPS II Combi is the second smallest in the collection. The total weight is 33.5kg, so pretty impractical for any mobile use. However, the mount can be taken apart in two pieces of 18 and 15kg respectively, which makes it remarkably easy to carry around. Maximum load capacity is 50kg. The GM2000HPS is equipped with absolute encoders. These are high-precision devices that allow the mount to know its exact position with <20 arcsec precision. And it remembers this position at all times, even if you unlock the clutches and rotate the mount manually. The absolute decoders allow unguided imaging with exposures up to 15-30 minutes.
For unguided imaging, a mount-model is required. This model is built by taking images at several positions and plate-solving those images so that the actual RA and DEC can be determined. A model needs at least 3 points, but the more points, the better. With enough points, the mount can correct for tracking errors and flexure, atmospheric refraction, etc. Building a mount model can be automated using software such as MountWizzard4, which is specifically designed for 10Micron mounts. This mount is permanently stationed at the observatory in Spain, where the models typically have 80-99 points. One of the benefits of using mount models is that small deviations in polar alignment or levelling are automatically corrected. If polar alignment is not completely perfect, there is a small risk of field rotation, but only when imaging at high altitudes (>80°) and long exposures (>15min).
The GM2000 HPS II COMBI is controlled with exactly the same control-box and hand-controller as the GM1000HPS. For firmware updates and updates on comets, satellites, as well as earth rotation data, a small piece of (Windows only) software is provided by 10Micron. In this blog post there is more detailed info on how this works.
Specifications
Mount Type: German Equatorial
Weight: 18.5kg (bottom), 15 kg (top), 33.5kg (total)
Payload capacity: 50kg
Counterweight shaft: 40mm, stainless steel, 4kg
Tracking: absolute encoders on both axes
Guiding: unguided, accuracy 0.6” RMS for 15min using multi-point model
Electronics: Control box with Linux-based operating system
Connectivity: Ethernet or WiFi
Altitude adjustment
There is one adjustment knob for altitude adjustment and two knobs on each side to keep altitude in place. The mount can be used at locations within latitudes 20° - 70°. There are multiple attachment points for the altitude adjustment mechanism. Depending on the desired latititude, orientation of that mechanism has to be changed
COMBI
The ‘COMBI’ in the name indicates that the mount can be taken apart into two pieces. The DEC axis on top and the RA axis with mounting mechanism at the bottom. A multi-pole connector in the mount ensures full electrical connectivity between both parts of the mount. Unfortunately it does not support through-the-mount cabling.
Balancing.
A 40mm wide counterweight shaft is screwed into the top part of the mount. It supports the use of either 6kg or 12kg counterweights. The software in the mount has an auto balancing routine for both axes. With some close attention and a bit of time, it is well possible to balance the scope within 0.0% accuracy.