Farpoint 6 Inch 57.3 Series Universal Dovetail Plate (Radian Bar)

Product Overview

The Farpoint FDP573-6 is the shortest bar in the 57.3 Series — a 6″ light-weighted D-size (Losmandy-style) universal dovetail. The series began as the Radian lightweight universal D-style bar that Farpoint manufactured for OPT (Oceanside Photo & Telescope), sold under the Radian Telescopes brand. With OPT closed, Farpoint continued the line under the 57.3 Series name on the same tooling, and extended the design into this compact 6″ length alongside the original 14″ and a longer 21.5″ bar. It is machined from sturdy aluminum with a black anodized finish and carries the same light-weighted profile and mounting hole options as the longer bars.

Who It's For

This is a good match if you…

• run a mount with a D-size (Losmandy-style) saddle and are carrying a compact optical tube.
• are assembling a guide scope rig or an accessory stack where a 14″ bar is more length than the job asks for.
• already own 57.3 Series or Radian bars and want a matching short one for a second tube.
• are watching payload on a smaller mount and want the light-weighted profile rather than a solid bar.

Key Features & Design

• 6″ D-size bar: a full Losmandy-standard dovetail profile in the shortest length Farpoint offers in this series.
• Light-weighted construction: material is machined away where it does not carry load, which is the design the Radian bar was known for.
• Mounting hole options: a variety of hole positions along the bar rather than a pattern drilled for one telescope.
• Black anodized aluminum: machined from sturdy aluminum stock with an anodized finish.
• CNC-machined in the USA: same tooling and same shop as the original Radian bars.

Recommended Uses

• Mounting a small refractor or compact optical tube on a D-size saddle.
• Carrying a guide scope assembly parallel to the main tube.
• Building an accessory platform that needs a Losmandy-standard interface in a short footprint.
• Adding a second short bar so two tubes can share one mount.

Compatibility and Accessory Notes

This is a D-size bar, the standard also called Losmandy-style — the wider of the two common dovetail profiles. It seats in any mount saddle cut for D-size hardware. Mounts supplied with only a small Vixen-style (V-size) saddle take a V-size bar, or a D-size saddle conversion, instead. The hole options along the bar cover a range of ring and tube spacings rather than one fixed pattern, so the fit depends on the holes already in your rings or tube foot. The longer members of the family — the 14″ original Radian length and the 21.5″ bar — share the same design if you need more reach. Send us your tube and ring models and we will check the hole spacing for you.

Good to Know Before You Order

• The bar ships on its own. Rings, radius blocks, and tube screws are separate items.
• 6″ is a short bar. It gives a smaller clamping footprint in the saddle than a 14″ or 21.5″ bar, which is what suits it to compact tubes and guide scope work.
• D-size and V-size are different profiles. A D-size bar seats in a D-size saddle; a V-size saddle takes the narrower V-size bar.
• Bare aluminum dovetail edge. Saddles that clamp with a set screw bear on the anodized edge; saddles with a clamping bar spread the load across the face.
• Vendor pricing on this item is under review. The published figure at the manufacturer currently reads 0.00, so our price is pending verification — get in touch and we will quote it directly.

Frequently Asked Questions

Is this the Radian dovetail bar?

It is the compact extension of it. Farpoint manufactured the original 14″ bars for OPT, who sold them under the Radian Telescopes brand. With OPT closed, Farpoint sells the line direct under the 57.3 Series name, and this 6″ brings the same design to the smallest rigs. The original length continues as the 57.3 Series 14″ bar.

Why choose the 6″ length?

Small refractors, guide scope rigs, and accessory assemblies do not call for 14″ of bar. The 6″ keeps footprint and weight down while still giving a full D-size dovetail.

What mounts does it work with?

Any mount with a D-size (Losmandy-style) saddle. Mounts that ship with a small Vixen saddle can take a D-size saddle conversion instead.

Is it difficult to install?

Installation is bolting the bar to the rings or tube foot through the matching holes and sliding it into the saddle. It calls for hand tools and no modification to the bar.

What does light-weighted mean here?

Material is machined out of the bar in the areas that carry little load, so the bar keeps its stiffness while shedding mass — the feature the Radian design was built around.

Bottom Line

In short: the 6″ member of Farpoint's 57.3 Series, a black anodized light-weighted D-size Losmandy dovetail bar CNC-machined in the USA on the original Radian tooling, sized for compact tubes, guide scopes, and accessory mounting.