Avalon M-Zero mount and tripod
A portable tracking mount with plenty of unusual features
An obvious way of combating light pollution is to carry out your observing and imaging sessions from a location with dark skies. However, that assumes that you can easily transport all your equipment – and if you want to image deep-sky objects in particular, that can be problematic.
Many mounts claim to be portable, but the Avalon M-Zero really is. Both the mount itself and the T-Pod 90 tripod are fabricated from lightweight alloy with a beautiful red anodised finish and stainless steel fittings – even the counterweight is stainless steel. Each is supplied in its own padded carry bag.
The diminutive size of the M-Zero mount means that the StarGo electronic control box needs to be mounted externally on one of the tripod legs and connected to the right ascension (RA) and declination (dec.) motors via fly leads. The control box incorporates a host of additional connections: an industry-standard ST-4 port for autoguiding; a direct connection for the popular Baader Steeldrive motorised focus system; and two auxiliary outputs for controlling additional stepper motor devices such as focusers and filter wheels. To emphasise the mount’s imaging credentials, there is a built-in electronic shutter release for a DSLR camera.
Another built-in module, this one for Bluetooth wireless, allows you to control the mount via an Android smartphone or tablet (control via iOS devices is not currently supported). A final connection is provided for the simple handpad, on which are buttons to slew the mount and operate an electronic focus motor. Surprisingly, the handpad feels rather cheaply made in comparison with the high quality of the rest of the mount and its ‘retro’ appearance also seemed at odds with the overall design.
The mount can be used in both equatorial and altaz modes by selecting the relevant mounting hole on the altitude adjustment’s quadrant. Rather surprisingly, the mount can be configured as a standard equatorial for any type of telescope or as a single tine equatorial fork for use with short tube scopes such as Schmidt-Cassegrains and Ritchey-Chrétiens. In the latter mode, there is no requirement to carry out a meridian flip, which is a real plus point for imaging.
The drive system is unusual too, as it uses pulleys and toothed belts instead of the more usual worm gear. This results in zero backlash and very smooth tracking, giving the mount a claimed periodic error of ±5-7 arcseconds.Setting up the mount was a straightforward task for one person, but we had to adjust the position of the single tine fork to achieve balance with our refractor – a suitable Allen key is supplied for this purpose.
To get the best performance from this mount, we found it necessary to balance both axes very accurately. During the balancing process, we had to be very careful not to snag the rather short declination fly lead. We used a smartphone app to determine the position of Polaris, as seen through the supplied polarscope, to achieve accurate polar alignment. Then, using free planetarium software Cartes du Ciel, we synchronised the mount with the bright star Vega in Lyra. We chose a series of different objects to observe along the Milky Way but – as was suggested in the manual – we found that it was necessary to resynchronise the mount as we went to ensure that each subsequent object appeared in the eyepiece.
There isn’t an option to carry out a multiple-star alignment, which would have increased the accuracy of the Go-To system. However, our tests showed that once centred, an object stayed there until we completed the test two hours later. Using our SXVF-M25C camera with a focal reducer and off-axis-guider we were able to easily capture 10-minute exposures with good star shapes. For observers and imagers looking for an easily transportable mount, the Avalon M-Zero would make an excellent choice.
Avalon’s earlier mounts were controlled by Synta’s motors, control boards and SynScan hand controllers, but the M-Zero introduces the company’s own control system, called StarGo. The StarGo system has been designed very much with the future in mind, relying on the use of a computer, or an Android smartphone or tablet, rather than an ‘intelligent’ wired hand-controller such as those supplied with most other Go-To mounts.
Connectivity is achieved by a USB cable for computers or Bluetooth wireless for Android devices. The ASCOM driver acts as a ‘hub’, allowing various other ASCOM programs to be connected to the mount at the same time. This means that planetarium software such as Cartes du Ciel or Stellarium can be used to supply an inexhaustible range of objects to observe, while positional feedback can be supplied to other software such as MaxIm DL.
Alternatively, the StarGo software (supplied on a rather smart memory stick) can be plugged into a computer and used on its own, allowing you to select from the 14,000 objects stored in the editable data files included with the mount.
Dovetail clamp - The Vixen-compatible dovetail clamp represents a great improvement over the standard clamping bolt design employed on most mounts of this size. In addition to the use of precision anti-marring clamping surfaces, the clamp is spring-loaded and has a generous locking knob that is easy to operate, even when wearing gloves.
Altitude adjustment - Adjusting the altitude of an equatorial mount to match your latitude is an important part of the polar alignment process, but it can be a delicate operation. The unusual method employed in the M-Zero uses an adjustment wheel and a quadrant with four mounting positions, allowing four ranges of adjustment to be made.
StarGo handpad - The supplied handpad can be used to manually slew the mount in RA and dec., and can also be used to control an electronic focuser – but it has no Go-To functionality. We found it very useful for fine tuning the pointing of the telescope after we had issued a Go-To command from our planetarium software.
Avalon tripod - The substantially built but light tripod is very simple to level and adjust for height. It includes a built-in spirit level. Two clamps retain the extendable tubular legs in position, and we particularly liked the ball and socket feet. The centre leg spreader is made from rectangular aluminium spars.
Illuminated polarscope - Obtaining accurate polar alignment is vital for ensuring precise slewing and reliable tracking during long-exposure astrophotography. The simple, illuminated polarscope supplied with the mount can to do this with the aid of suitable computer software or a smartphone app. The brightness of the LED is software controlled.
This review originally appeared in the November 2014 issue of BBC Sky at Night Magazine.