Machine moving carriages: Click each small image to see it full-screen
Disclaimer: This describes a tool made for my own use in performing an inherently risky task. Use at your own risk.
I made these machinery-moving carriages to ease the process of solo machine-moving.
These carriages have an advantage over the professional e.g. Hilman track rollers in that the machine only needs to be raised a mere 3/4" off the floor. This lowers the risk of catastrophy should a machine slip off and tip.
My heaviest machine is a Gorton mill that weighs 5500 lbs, pictured in the top photo, this was the design goal for the carriages. The eight casters are rated 700 lbs each. I did no bending or weld-strength calculations for the frame, but I'm pretty confident that they're good for it. In any event there was no visible deflection with the Gorton sitting on them.
The basic idea is a matched pair of carriages with a long finger that slide under a machine and support it just high enough to roll clear of the floor.
Each carriage has four wheels to make them independently stable, and the finger is located along the center of gravity so that even with a full load they can't tip.
The carriages are welded up from 2x3x1/4" and 2x2x1/4" angle stock, with reinforcements cut from 1/4" flat stock. The casters are no-name imports from MSC, 4"x2" steel-wheel with full roller bearings, rated 700 lbs each. The cheap imports are fine, but I deliberately selected steel wheels with full bearings to minimize the friction when rolling several tons.
The overall dimensions of each carriage are 17" x 42", with an inside clear width of 34". This means 34" is the widest that the narrow dimension of the machine can be. The length limited only by how flat the floor is.
They're hard to spot in the photos, but the top rails have holes drilled to facilitate bolting the carriages together to ensure they don't slip out from under a machine.
I also made a special 5' prybar designed to lift a machine the short distance to slide the carriage under. One end of the prybar has a short piece of 1/4" plate welded on at a 30 degree angle; the other end has a piece at 60 degrees.
The bar is schedule 40 steel pipe, and the pivot is 1/2" round bar.
Note the 4" gap in the carriage fingers, it's there to leave room for the prybar to reach under the carriage.
The prybar is also convenient for steering the carriages, lifting and twisting.