Farpoint Dovetail Plate - Celestron 8 Inch RASA

Product Overview

The Farpoint FDC8-RASA is a complete mounting kit that carries a Celestron 8″ RASA astrograph on any D-size (Losmandy-style) saddle. It is built around a 19″ dovetail bar paired with radius blocks machined to the curve of the 8″ RASA tube, and the mounting screws come with it. The parts are CNC-machined in the USA from aluminum with a black anodized finish, and the kit weighs 2.375 lb.

Who It's For

This is a good match if you own a Celestron 8″ RASA and a mount with a D-size (Losmandy-style) saddle, and you would rather buy the bar, the tube interface and the hardware as one kit than source them separately. It also suits you if you move the RASA between several mounts that share the D-size standard and want one bar that drops into all of them.

Key Features & Design

• 19″ dovetail bar: The full 19″ length gives the saddle a long clamping run and leaves room to slide the tube fore and aft for balance once a camera and filter drawer are hanging off the back.
• Radius blocks matched to the tube: The blocks are machined to the curve of the 8″ RASA specifically, so they sit flush on the tube rather than touching at an edge.
• D-size (Losmandy-style) profile: The bar follows the wider D-size dovetail standard used by Losmandy-style saddles.
• Mounting screws included: The screws that join the blocks to the tube's existing mounting points ship in the box.
• Black anodized aluminum: The anodized finish keeps the bar non-reflective next to the optical path and resists handling marks.
• CNC-machined in the USA: Every part in the kit is machined rather than cast or extruded to profile.

Mechanical Design

The RASA tube is round and a dovetail bar is flat, so on their own the two meet along a narrow line. The radius blocks bridge that gap. Each block is machined to the exact curve of the 8″ RASA tube, which spreads the clamping load across the whole contact surface instead of concentrating it at the bolt holes. The connection between tube and saddle comes out stiffer, and the tube carries less local stress — something that shows up on a fast wide-field astrograph, where any flexure in the mounting chain lands in the corners of the frame.

Recommended Uses

• Mounting a Celestron 8″ RASA on a Losmandy-style German equatorial for wide-field imaging runs.
• Rebalancing the RASA after adding a camera, filter drawer or off-axis guider, using the length of the 19″ bar.
• Moving one RASA between a portable D-size mount and a permanent pier setup without changing the tube hardware.
• Replacing an original short bar that leaves the tube nose-heavy at the saddle.

Compatibility and Accessory Notes

The radius blocks in this kit are cut for the Celestron 8″ RASA optical tube assembly, and the block curve is specific to that tube diameter — the 11″ and 14″ RASA models take their own kits. The 19″ bar is a D-size (Losmandy-style) dovetail, so it seats in Losmandy saddles and in the D-size saddles used by mounts such as the Celestron CGEM and CGX families, iOptron and Sky-Watcher D-size heads, and any third-party D saddle cut to the same standard. A V-size (Vixen) saddle takes a narrower bar and is a different fit. The kit bolts to the tube's own mounting points using the screws supplied. If you are unsure which RASA you have or which saddle standard your mount uses, let us know the model and we'll confirm the fit.

Good to Know Before You Order

• The telescope is not included. This kit covers the bar, radius blocks and mounting screws only.
• The blocks are tube-specific. They are machined to the 8″ RASA curve and will not sit flush on a tube of a different diameter.
• The bar is D-size only. Fitting it to a Vixen-size saddle would call for a saddle change or an adapter.
• Kit weight is 2.375 lb. That mass rides on the mount alongside the tube and counts toward the mount's payload figure.
• The 19″ bar extends past the tube at both ends on some configurations. That overhang is what gives the balance range, and it can sit close to the mount head at extreme declinations.

Frequently Asked Questions

Is it difficult to install?

It is a straightforward bolt-on. The radius blocks fasten to the RASA's existing mounting points with the supplied screws, then the bar attaches to the blocks. A hex key and a few minutes on a bench are the whole job.

Does this fit the 11″ or 14″ RASA?

No — the radius blocks here are machined to the 8″ RASA tube curve. The larger RASA models use kits cut to their own diameters.

Will it fit a Vixen-style saddle?

The bar is a D-size (Losmandy-style) dovetail, which is wider than the Vixen V-size profile. It seats in D-size saddles.

Are the mounting screws included?

Yes. The kit ships with the 19″ bar, the matched radius blocks and the mounting screws.

Why use radius blocks instead of bolting the bar straight to the tube?

The tube is curved and the bar is flat. The blocks fill that curve so the clamping force spreads over the contact area rather than loading the bolt holes, which keeps the tube from being stressed.

Bottom Line

In short: a 19″ D-size bar with radius blocks cut to the Celestron 8″ RASA tube and the screws to fit them, CNC-machined in the USA and weighing 2.375 lb — the complete interface between that astrograph and a Losmandy-style saddle in one box.