TS 2'' Dual-speed Monorail Focuser for Refractors with 86 mm Flange

TS 2" Dual-speed Monorail Focuser for Refractors with 86 mm Flange

  (1 Review)
✓ 2 year warranty


Out of stock due 15-20 working days

About this product

Model:  ts_monorailr86
Part Number:  MONORAILR86

TS Monorail 2" Refractor Focuser - Dual Speed - for 86 mm Flange

TS-Optics 2" MONORAIL Focuser with 86 mm Flange

The TS Monorail focuser fits many Skywatcher, Celestron and Orion refractors and is an improvement over traditional Crayford focusers.

The MonorailR86 has an 86 mm connecting flange on the telescope side with three M4 internal threads. This allows the connection to Skywatcher, Celestron and Orion refractors with 90 mm tubes (often used with 80 mm and 90 mm objectives).

The advantages of the TS Monorail focusers at a glance:

  • higher load capacity than with normal Crayford focusers - instead of small ball bearings, there is a laterally clamped stainless steel rail
  • more precise guiding of the draw tube and no more tilting when locking
  • smooth motion and finest adjustment even at loads of up to 4 kg
  • 1:10 dual speed for accurate focusing
  • Motor focus can be retrofitted
  • Telescope connection: 86 mm flange with three radial M4 thread bores
  • Eyepiece side connection: 2" and 1.25" receptacle with compression ring
  • Minimal height to flange: 91 mm
  • Draw tube travel: 50 mm
  • Dual speed 1:10 for accurate focusing
  • Bearing via stainless steel rail - free from twisting
  • Central locking of the draw tube, guaranteed without tilting

Operating principle of the Monorail focuser and the advantage compared with Crayford focusers:

Instead of small ball bearings, like in Crayford focusers, a massive stainless steel rail handles bearing and lateral fixing.

The disadvantage of Crayford focusers with ball bearings: The small ball bearings of the Crayford focuser are loaded if locked. As the locking screw is not placed precisely between the ball bearings, one pair of bearings is more heavily loaded. This results in tilting and unsharp stars in one corner.

The advantage of the MONORAIL principle: Instead of ball bearings, a stainless steel bar is firmly connected to the draw tube. Nothing can bend anymore. Only lateral guidance is taken over by ball bearings. These bearings only fix the lateral position and no longer need to take on the load.

The drawtube is fixed with a locking screw centred at the upper side, so the entire construction is evenly loaded. Tilting is avoided. The draw tube stays precisely at the given position.

With the middle screw of the "quincunx", only the friction is adjusted.

Customer reviews

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Perfect swap for my old Vixen M80 focuser
15 May 2024  | 

Fits like a glove.
The 3 Vixen screws are a different thread to the TS M4 so found some M4s in my box of bits (the TS doesn't come with any).
The TS focuser has the 3 holes offset/rotated compared to the Vixen focuser, making the TS look askew relative to the red "Vixen" logo.
It really doesn't matter. But TS has a knob to loosen which lets you rotate it, so now everything looks neat and tidy.

I had a few grands worth of solar astronomy gear dangling off the back of my Vixen.
All that was keeping it there was a small 1p thumb screw on the Vixen focuser.
Replacing it with this TS 86mm was a no brainer for the insurance alone. It has an inner brass ring clamp with 2 heavy duty thumb screws.

A sturdy well made focuser. Very pleased with it.


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