Mountain Instruments MI-250 German

PRICE - $3350

MI-250 FAQ's

The Mountain Instruments (MI)-250 is a rock solid German equatorial mount that features the renowned precision of a Losmandy 7.5" RA drive and matching worm. This robust field mount was engineered and designed for SCT's, refractors, and Newtonians alike. For those requiring true versatility in an affordable package without sacrificing incredible stability, this is your mount.

 The conical polar housing has been expertly cast in a #319 aluminum alloy and then painstakenly machined. Based in part on the Russell Porter designs, the polar shaft is also conical in shape for maximum stability. An internal slip clutch has been integrated for silky smooth movement of the RA axis. The entire gear train, electronics, and bearings are internal.

Like the polar base, the German equatorial head features a conical shape offering total rigidity. The isolated counter weight shaft is independent of the declination shaft and is easily removed for transportation. A unique tangent arm assembly features instant response with NO backlash. This design is exclusive to Mountain Instruments! You won't find lead screws or lead screw backlash in this German declination assembly, but you will find total responsiveness and control.

Your MI-250 purchase also includes features not found on competing mounts in this price range. With its built in electronics package, operating on 12 volts dc or a 9 volt battery, it is a pleasure to use. The microprocessor even offers PEC! The four guide rates, sidereal, solar, lunar, and King are all push-button simple. A palm-sized hand paddle not only features directional control but also has focuser control and a map light. The pre-installed, high resolution 8192 step encoders, enable the user to interface with the Mountain Instruments STAR PILOT and most other popular digital setting circles or THESKY from Software Bisque.

*** The redesigned base offers features not found on previously models. Fine tuning in altitude and azimuth are effortlessly performed without the need of tools! Micro smooth adjustments in both axis. Positive ratchet type lock-down then secures both axis for trouble free use.***

A custom pier can be ordered with the mount for field use or designed for permanent installation. For those with a Meade or Celestron field tripod, a convenient adapter plate can be supplied to secure the Model 250 equatorial head.

The wear resistant powder coated castings, with black anodized aluminum, flawless lines and fine craftsmanship, make it as beautiful to look at as it is to use. And the best for last.......Timely delivery!

Polar Assembly

• 65-70 pound payload capacity (dependent on moment arm of OTA)
• Easy 5 minute set up time
• 7.5" Losamndy RA drive
• Matching precision ground Losmandy stainless steel worm
• Conical shape for maximum rigidity
• Conical polar axis
• Major polar axis bearing-3.74" diameter
• Pre installed internal 8192 step encoder
• Variable friction slip clutch
• Internal electronics package (see below)
• Beautiful powder coated and black anodized finish
• Redesigned altitude and azimuth adjustments!
• Total RA (conical section) weight-27 pounds
• Tripod adapter plate available
  

German Declination Assembly

• Conical shape
• Massive 3.74" major bearing
• Unique "no backlash" tangent arm assembly
• Easily secures onto polar base in less than 2 minutes
• 16 pounds total-42 total pounds when assembled to RA assembly. (not including c.w.'s or shaft)
• Isolated and removable counter weight shaft
• 15 pound counter stainelss steel weight
• Same attractive powder coated and anodized aluminum as polar base
• Pre installed and protected 8192 step encoder
• Saddle plate easily accepts most commercial tube rings including the LOSMANDY dovetail series
• Easy access to RA clutch adjustments

Dual Axis Digital Drive Electronics

• Microcomputer electronics package
• Pre installed and panel mounted
• Selectable guide button direction
• Compact hand control
• CCD autoguider capabilities
• Northern/Southern Hemisphere operation
• Periodic error correction (PEC)
• Guiding rate +/- 35% sidereal
• Star centering rate +/- 4x's sidereal
• Accurate tracking speed +/- 0.1%
• 9 or 12 volt operation
• Battery- up to 25 hours operation
• Focuser plug in and buttons on hand control
• Hand controller map light
• Tracking: Sidereal, Lunar, Solar, King
• RA motor-DC Servo with magnetic encoder- very high torque- low energy use