JMI Heavy-Duty Medium Universal Wheeley Bar — Telescope Dolly

The JMI Heavy-Duty Medium Universal Wheeley Bar is JMI's most popular telescope dolly — the one that fits the widest range of tripods used by imagers and visual observers alike. Roll your fully assembled rig from storage to your observing spot without breaking down the setup, disconnecting cables, or losing polar alignment. Lock the wheels, level the base, and start observing.

With a 34″–42.5″ tip-to-tip range, it covers the Celestron HD Pro Wedge tripod, Losmandy tripods, iOptron tripods, and many others. Rated to 300 lb. Ships with 5″ polyurethane wheels and heavy-duty 5/8″ leveling screws. Built by JMI on welded steel. Made in California, USA.

Product Overview

The JMI HD Medium is a 300 lb-rated steel telescope dolly for tripod-mounted telescopes with a tip-to-tip spread of 34″ to 42.5″ at observing height. It is the most versatile model in the heavy-duty Universal line and fits the majority of popular GEM tripods used for imaging and serious visual observing.

Who Is This Product Best For?

Astrophotographers and serious visual observers with GEM-mounted setups in the 50–300 lb range. If you own a Celestron CGX, AVX, CEM60, or similar mount on a standard tripod, and you store the assembled rig in a garage or observatory-adjacent space, this is the right model.

Why Choose This Product?

• Most popular HD model: Fits the widest range of commonly used tripods in the 34″–42.5″ tip-to-tip range.
• 300 lb capacity: Fully supports heavy imaging trains — mount, OTA, cameras, counterweights, and cabling together.
• Session-to-session alignment: Roll out, observe, roll back — polar alignment and cable routing survive every session.
• 5″ polyurethane wheels standard: Stable and smooth on concrete, driveways, and patios.
• USA-made: Welded steel frame, powder-coat finish, engineered to last.

Compatibility and Accessory Notes

Fits tripods with a tip-to-tip distance of 34″ to 42.5″ at observing height. Tripod foot receptacle is 2-3/4″ I.D. Optional 10″ pneumatic all-terrain wheel upgrade and full-size Tie-Down Bracket Kit available separately.

Important Limitations

• Tip-to-tip range 34″–42.5″ — measure your tripod before ordering
• Tie-Down Bracket Kit sold separately
• Standard 5″ wheels for hard surfaces; 10″ pneumatic needed for grass or gravel
• Always push or pull below the telescope's centre of gravity

Frequently Asked Questions

Will this fit my Celestron CGX or AVX tripod?
Most Celestron HD-grade tripods fall within the 34″–42.5″ range. Set your tripod to observing height and measure tip-to-tip to confirm before ordering.

What is the difference between the HD Medium and HD Shorty?
The HD Medium spans 34″–42.5″ and fits most popular mid-size tripods. The HD Shorty spans only 26.25″–31.25″ and is designed for compact tripods and maximum doorway clearance.

What is the difference between the HD Medium and HD Large?
The HD Large spans 49″–56.5″ for very large-leg telescopes like the Losmandy Titan and observatory-class tripods. If your tripod falls in the 34″–42.5″ range, the HD Medium is correct.

Our Recommendation

The HD Medium is the right starting point for most serious imagers. Measure your tripod tip-to-tip first — if it lands between 34″ and 42.5″, this is your model. For wider tripods or the tallest observing positions, check the HD Large. For tight doorways and compact tripods, consider the HD Shorty.