What is the 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 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-2 is a 2" black-anodized aluminum focuser with knurled knobs. The motorized focuser lifts up to 4 pounds. Manual control is over 1½ times finer than most rack-and-pinion focusers.
The motorized 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
- Integrated Motor For Smooth Performance
- Lifts Up To An Eight Pound Payload
- 1.25" Eyepiece Adapter And Hand Control 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: EV2NM
- Additional Information
SKU JM-EV2NM Manufacturer JMI Focuser Design Crayford Focuser or Mask Size 2" Drawtube Focus Control Motorized Warranty 1 Year Warranty
- Included Items
- JMI Event Horizon EV-2nM Motorized Newtonian Focuser
- 1.25" Adapter
- Integral Drive Motor
- Hand Control
- Questions & Answers
Product QuestionsHi, I have a GSO made 8" Newt at F4 and I am interested in this focuser as a replacement to the factory one. What I would like to know, is
what do I need in order to mount this focuser to the tube? Does it come with adapter plates or do I need to buy a kit to install?
Thanks.Question by: Goran on May 25, 2015 8:03:00 PMHello Goran,
Thank you for your question. The hole spacing on the adapter plate that comes with this focuser is 72mm.
That is the same for the hole spacing on this telescope so nothing else is needed to get this focuser on this optical tube.Answer by: Rod Gallardy (Admin) on Jun 2, 2015 4:05:00 PM
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