Cloud Break Optics

2-inch to 3"x24tpi Male Thread Adapter (17666)

2-inch to 3"x24tpi Male Thread Adapter (17666) - Main image
$68.4 $95 In stock

Category: Astrophotography Accessories

Description

Adapters for 2-inch Focuser Drawtubes

2-inch O.D. Adapters to fit the TCF-S and other 2-inch focusers.

Each of our 2-inch Drawtube adapters are machined to tight tolerances for a smooth, snug fit into the TCF-S and TCF-Si 2-inch focuser drawtubes. A dovetail cut directly matches the thumbscrews on the TCF-S for a secure fit.  By tightening the thumbscrews, the adapter is drawn tightly into the focuser's drawtube.

These 2-inch drawtube adapters will usually fit very well into other manufacturer's focusers as well.   Contact Optec for any 2-inch drawtube adapter not listed here.

#17666 - 2-inch to 3"x24tpi male  thread Adapter.

The 2-inch to 3-inch thread adapter was developed to easily adapt the Apogee and SBIG cameras and filters wheels for the TCF-S focuser.

By holding tight tolerances (+/- 0.003") Optec has achieved a slip-fit that is second-to-none.  When used with the TCF-S focuser, the #17666 with its  precision machined dovetail cut exactly matches the three thumbscrews on the focuser's  drawtube.  By tightening the thumbscrews, the dovetail is drawn tighter to the face of the drawtube completely eliminating flexure.

A word of caution, however, the FLI cameras and filter wheels featuring a 3-inch x 24tpi thread are slightly larger (3.005").  Be certain the #17666 2-inch nosepiece fits snugly into the FLI camera or filter wheel before installing into the TCF-S focuser.  Additionally, the FLI filter wheels allow only 0.100" of thread to extend into the filter wheel body without obstructing the moving filter carousel.

Specifications

  • Overall Outside Diameter:  3.2" (81mm)
  • Outside Diameter (drawtube body):  1.995" (50.7mm)
  • Overall Height: 2.32" (59mm)
  • Height of 3x24 threads:  0.22"  (5.6mm)
  • Clear Aperture: 1.80" (45.7mm)
  • Weight: 3.0 oz (85 g)
  • Back-focus Usage: 0.10" (2.75 mm)

Compatible with:

  • TCF-S or TCF-Si focuser,
  • TCF-S3 or TCF-S3i focuser with #17804 3-inch to 2-inch reducer,
  • Any manufacturer's 2-inch focuser or receiver.
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Customer Reviews (4.8 / 5 · 5 reviews)

John ★★★★★

Threads on perfectly into my 2-inch focuser drawtube, no wobble or play at all after tightening. The machining really is precise—that snug fit gives me confidence my camera won’t shift during long exposures.

Lily L. ★★★★★

The machining on this adapter is noticeably precise—it slides into my focuser with zero wobble. I was worried about threads not catching, but they engage smoothly and hold firm. Exactly what I needed for my imaging train.

Ryan Q. ★★★★★

I needed a solid adapter for my 2-inch focuser drawtube and this one slides on snug with zero wobble. The tight machining is noticeable when you first fit it.