Farpoint 108mm Vixen Dovetail Rings with Dovetail

Product Overview

The Farpoint FVDR108 is a complete tube ring set — two rings of 108 mm inside diameter, each with three-point adjustment, supplied already mounted on an 8″ Vixen-style (V-size) dovetail bar. Nothing is left to assemble or drill: the optical tube clamps in the rings and the bar drops straight into a Vixen saddle. Farpoint machines and assembles the set in the United States, and the finished assembly weighs 2 lb.

Who It's For

This is a good match if you…

• have an optical tube of 98 mm outside diameter or less and want the rings and the bar in one purchase.
• are mounting a small refractor or a large guide scope on a Vixen-style saddle.
• want three-point centring rather than the two-screw arrangement used on lighter rings.
• would rather not measure, source and drill a separate bar to match a ring spacing.
• rotate the tube between sessions to reposition a focuser or finder.

Key Features & Design

• 108 mm ring inside diameter: accepts optical tubes up to 98 mm outside diameter — the ring I.D. less 10 mm — and any smaller tube within the adjustment range.
• Three-point adjustment: each ring carries three adjusters, so the tube is centred on three contact points rather than pinched between two.
• 8″ Vixen dovetail bar included: the V-size bar ships with both rings already fitted and spaced.
• Single-piece assembly: ring spacing and bar alignment are set at the factory, so the two ring bores arrive coaxial.
• Made in the USA: machined and assembled by Farpoint in the United States.
• 2 lb assembly weight: rings and bar together add 2 lb to the load the mount carries.

Mechanical Design

Three-point adjustment spaces the contact screws evenly around each ring, which holds the tube on its own axis instead of pushing it toward one wall of the ring. That shows up when the tube is rotated to bring a focuser or finder to a new angle, because the optical axis stays where it was. Both rings are mounted to the 8″ bar at the factory, so their bores are already in line and no shimming is involved. The bar is a standard V-size profile — the same cross-section a Vixen saddle clamps on — and its 8″ length sets how far the assembly can slide fore and aft for balance.

Recommended Uses

• Mounting a 3″ to 4″ refractor on a Vixen-saddle equatorial or alt-azimuth mount.
• Carrying a large guide scope beside a main instrument on a side-by-side plate.
• Rotating a tube to bring the focuser to a comfortable viewing angle while keeping pointing.
• Replacing clamshell rings where independent ring spacing along the tube is wanted.
• Building a travel setup where the rings and bar stay together as one unit between sessions.

Compatibility and Accessory Notes

The dovetail is V-size, the Vixen standard, and it seats in the saddles found on Sky-Watcher EQ and AZ mounts, Celestron CG-5 and Advanced VX, iOptron equatorials, and the dual-format saddles on Losmandy and Sky-Watcher EQ6-R class mounts, along with any other clamp cut for a Vixen profile. A saddle machined only for the wider D-size (Losmandy) profile takes a different bar or an adapter. On the tube side the working range runs from 98 mm outside diameter downward: a tube near 98 mm sits with the adjusters barely extended, a smaller tube with them further in. If you are unsure where your tube falls, send us its make, model and measured outside diameter and we will check the fit for you.

Good to Know Before You Order

• Ring I.D. is 108 mm, usable tube O.D. is 98 mm. The 10 mm difference is taken up by the adjustment hardware, so 98 mm is the largest tube the set holds.
• The bar is 8″ long. That length sets the available balance travel in the saddle; a longer bar gives more fore-and-aft range.
• The dovetail is Vixen, not Losmandy. A saddle cut solely for the D-size profile calls for an adapter or a different bar.
• Farpoint publishes no tube liner or padding for this set. The adjusters bear on the tube directly.
• Published weight is 2 lb. Rings and bar ship together as a single item.

Frequently Asked Questions

Is it difficult to install?

No. The rings arrive already on the bar, so fitting comes down to opening the rings, seating the tube, snugging the three adjusters on each ring until the tube is centred, and sliding the bar into the saddle.

What size tube does it hold?

Any tube of 98 mm outside diameter or less. The rings measure 108 mm inside and the adjustment hardware occupies the remaining 10 mm.

Can the tube be rotated after it is clamped?

Yes. Backing the adjusters off lets the tube turn in the rings, and the three-point arrangement brings it back to the same centre when they are snugged again.

Does it fit a Losmandy saddle?

It fits any saddle that accepts a Vixen (V-size) profile, including dual-format saddles. A clamp cut solely for the D-size profile is a different standard.

Is the dovetail bar sold separately?

Here it is included. The 8″ V-size bar comes with both rings already mounted to it.

Bottom Line

In short: a 2 lb US-made assembly of two 108 mm three-point rings on an 8″ Vixen bar, covering optical tubes up to 98 mm outside diameter under a single part number.