JMI EV-3n Event Horizon Newtonian Focuser

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JMI EV-3n Event Horizon Newtonian Focuser
$219.00
Item # JM-EV3N
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  • A JMI Event Horizon EV-3n is a 2" black-anodized aluminum focuser that lifts up to 4 pounds.
  • Newtonian version mounts onto a range of surfaces, from a tube that is 7.25" diameter or larger, to a flat surface.
  • The JMI Event Horizon EV-3n provides zero image shift, zero backlash and tolerances that are 100X better than rack-and-pinion focusers!
Description

Details

What is the JMI Event Horizon Focuser?

The Event Horizon Focuser (EV) is a low-profile, friction-drive focuser designed for both the amateur and professional market. The highly acclaimed Crayford design (see below) permits tolerances up to 100 times better than conventional rack-and-pinion focusers. Zero image shift and zero backlash makes it fantastic for visual and photographic work and a must for CCD imaging. The modular design makes changes and upgrades extremely easy to accomplish. Add the optional variable-speed Motor and Smart Focus, Digital Read Out (DRO) or Digital Focus Counter (DFC), for the ultimate focusing system. The EV is truly a masterpiece of engineering and workmanship that you will be proud to own for years to come.

What is the Crayford Design?

The Crayford Eyepiece Mount (CEM) was invented by John ("Jack") Wall. The Crayford name comes from the Crayford Manor House Astronomical Society (UK) to which he belongs. The Crayford design uses high pressure on a metal drive shaft pressing against a metal drawtube which is held by bearings on the opposing side. This direct surface-to-surface drive mechanism eliminates backlash and shifting of the drawtube as seen in other designs such as the rack-and-pinion focuser and allows for very fine adjustments. JMI recognized the benefits of this design and was the first company to bring it to the amateur market in a commercial product.

The Event Horizon EV-3 is a 2" black-anodized aluminum focuser with knurled knobs. The focuser lifts up to 4 pounds. Manual control is over 1½ times finer than most rack-and-pinion focusers.

The Newtonian version mounts on a range of surfaces from a 7.25" diameter, or larger, tube to a flat surface. The focuser gives 1/2" of travel and is designed for fine focus after rough adjustment with the normal telescope focusing knob.

The JMI Event Horizon EV-3 Features...

  • Sealed Stainless Steel Ball Drawtube and Drive Shaft Bearings
  • 1.25" Eyepiece Adapter Included
  • Interchangeable Base
  • Modular, Black Anodized Aluminum Body Style
  • Knurled Aluminum Knobs
  • Surface-To-Surface Drive To Elminate Backlash
  • Modular Design For Easy Changes And Upgrades
JMI Product Number: EV3N
Additional Information

Additional Information

SKU JM-EV3N
Manufacturer JMI
Focuser Design Crayford
Focuser or Mask Size 2" Drawtube
Focus Control Manual
Warranty 1 Year Warranty
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Included Items

Included Items

  • JMI Event Horizon EV-3n Newtonian Focuser
  • 1.25" Adapter
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