Software Bisque Permanent Piers

Figure 1: Sample 46 cm (18-inch) Paramount ME Pier

Cost: $680.00 + shipping each

The Software Bisque Paramount ME permanent pier (sold separately) is available in heights ranging from 30.5 cm to 122 cm (12-inches to 48-inches). Software Bisque generally stocks 30.5 cm (12-in), 61 cm (24-in.), 91 cm (36-in.) and 122 cm (48-in.) piers. Custom height piers require up to 10 weeks delivery. Please call for availability.

Figure 2 – Paramount ME Pier with scale.

The bottom of the pier has four slotted holes that provide approximately 10 degrees of rotation (± 5 degrees) that allow adjustment of the polar azimuth.

The Paramount ME pier is constructed of two steel plates welded to a 25.4 cm (10-in.) diameter steel tube. The piers are powder coated on both the outside and inside to protect the steel from corrosion.

Figure 3 – Photograph of pier base plate. Note slotted holes.

Pier Base Plate

Figure 10 – Pier base plate dimensions shows the footprint of the Paramount ME pier. The pier can be attached to the ground with four 12.7 mm (0.50-inch) J-bolts placed in the concrete (J-bolts are available from any hardware store). We recommend that the base plate remain in contact with the cement surface to optimize damping.

Figure 4 - Pier base plate dimensions.

Pier Top Plate

Figure 5 - Paramount ME Pier Top Plate

The Paramount ME Pier Top Plate is slightly larger than the Base Plate. It is constructed out of 12.7 mm (0.50-inch) thick steel plate and is drilled in the corners to accept the Paramount ME. North is indicated in the above drawing (“South” for Southern Hemisphere installations). However, since the 23.9 cm (9.40-inch) hole pattern is symmetric about the center of the pier, any multiple of 90-degrees is acceptable.

Damping Pier Oscillations

A common "litmus test" that astronomers use to "measure" an imaging system's overall stability is to gently tap the side of the mount and then watch a star's motion through the telescope's eyepiece. The behavior of the star can give insight to the overall stability of the pier, mount and telescope system.

For example, if after only a few oscillations, the star returns to its original position within about one second (or so),  then the whole system is deemed "stable" and ready for imaging.

If, however, the star continues to oscillate for more that a few seconds, then one or more system components is either loose or somehow unstable. This can lead to problems when imaging and the mount is "moved" by wind or other sources of vibration (trains, highway traffic, etc.).

If you've stabilized every component of your imaging system (pier to mount, mount to telescope, eyepiece to telescope, filled the pier with sand), and still observe oscillations in the system, then check the pier to ground interface.

Problem

The interface between the pier's mounting surface (normally a concrete pier or pad) and the base plate of the Software Bisque Permanent pier can be a source for high-frequency oscillations.

This comes from the fact that the base plate is essentially "suspended" at the four corners, and may not be properly "grounded". The result is a mechanical "diaphragm" at the bottom of pier.

Since the pier is supporting a large amount of weight, small "taps" on the mount create a significant torque (force at a distance). So, a "weak link" is the pier's 0.5-inch thick metal base plate, which actually "bends" (by a very small amount) when the mount is tapped, and causes oscillations.

Solution

Place material to dampen vibrations between the pier's cylindrical bottom and the pier's mounting surface. Treated plywood is perhaps the best choice, and will last a very long time under most operating conditions.

Many Paramount ME customers report significant reductions in damping time using this technique.