Mounting Hardware

Dovetail Standards and Building a Rigid Connection

Nearly all mounting hardware follows one of two dovetail standards, and mixing them without the correct clamp is the most common cause of a telescope sitting loose on an otherwise good mount.

• Vixen-style dovetail (approximately 44 mm): The lighter standard, fine for small refractors and visual loads up to a few kilograms.
• Losmandy-style dovetail (approximately 75 mm): The wider, stiffer standard used for heavier optics and imaging trains where flexure must be minimized.
• Tube rings: Sized to the tube's outer diameter and lined to protect it; rings allow rotation for framing without unbolting the optic.
• Mount saddles: The receiving clamp on the mount head. Dual-fit saddles accept both standards, and face-clamping designs grip more securely than a single point screw.
• Side-by-side plates: Carry two optical tubes on one mount with balance adjustment in both axes.
• Adapter plates: Convert between standards, add accessory mounting points, or raise a guide scope clear of an obstruction.

Why Choose David Astro for Mounting Hardware

Rigidity is cumulative. Every joint between the optic and the mount either holds or contributes to the error you spend the night chasing.

• Standard matching: We confirm your mount's saddle type and specify a dovetail that fits it fully, rather than one that seats on an edge.
• Flexure diagnosis: If your guiding shows drift that guiding corrections cannot fix, we will look at the mechanical chain with you — usually it is a guide scope bracket or an undersized dovetail.
• Tube diameter fitting: Rings are matched to actual measured outer diameter, since nominal aperture and tube diameter are not the same number.
• Authorized dealer: Genuine hardware with full manufacturer warranty, shipped from Canadian stock.
• No cross-border fees: Canadian orders ship domestically with no duties or brokerage charges.

Mounting Hardware in Canada — Frequently Asked Questions

Vixen or Losmandy dovetail?

Losmandy for anything above roughly 7 kg or for imaging where flexure matters. Vixen is adequate for smaller refractors and visual use, and is lighter and more common on entry-level mounts.

Can I put a Vixen bar in a Losmandy saddle?

Only with a dual-fit saddle or an adapter clamp. Forcing a narrow bar into a wide clamp results in point contact, which is exactly the condition that causes slipping under load.

Why do my stars elongate only on one side of a meridian flip?

That pattern usually indicates differential flexure rather than tracking error. Check the guide scope bracket, the dovetail seating and the focuser drawtube, in that order.

How do I size tube rings?

By the tube's outer diameter, not aperture. Measure the tube itself, or tell us the exact telescope model and we will confirm the correct ring size.

Chasing flexure?

Tell us your tube, mount and payload and we will specify hardware that holds it solid. Ships from Canada with expert support.