FAQ

What is the load capacity of the Model 9 Spring Caster?

The Model 9 Spring Caster is rated for 550 pounds per caster. The spring constant is 540 lbs/inch with up to 1 inch of spring travel before bottoming out. For optimal shock absorption, total equipment weight should fall in the 500-1,000 pound range across four casters, which keeps each caster in the 25-40% static deflection zone where suspension performance is best.

What wheel sizes fit the Model 9 Spring Caster?

The Model 9 accepts 6×2 and 8×2 wheels (6-inch or 8-inch diameter, 2-inch wide). A wide range of wheel materials are available including polyurethane, rubber, phenolic, and nylon depending on your floor type and load requirements.

What makes the Model 9 swivel so smooth?

The lower raceway uses a tapered roller thrust bearing that counteracts radial thrust for exceptionally smooth swiveling action under load. The 2-9/16″ bearing raceway is precision machined and hardened, running on 3/8″ hardened ball bearings. This combination keeps steering effort low even at full capacity.

Is a brake available for the Model 9 Spring Caster?

Yes. The Model 9 is available with the FCB weld-on face contact brake for applications requiring position locking.

What finish does the Model 9 Spring Caster have?

The Model 9 comes standard with a zinc plated finish for corrosion resistance in industrial environments.

What size is the kingpin and axle on the Model 9?

The Model 9 uses a 3/4″ integrally forged kingpin and a 1/2″ axle. The forged kingpin eliminates threaded weak points found in bolt-on designs.

Can I use spring casters for server racks and data center equipment?

Yes. Server hard drives are rated for 50-70g shock during operation. A rigid caster rolling over raised floor tile transitions transmits impact spikes around 150g, which causes head crashes and data loss. The Model 9 spreads that same impact over 50-100 milliseconds instead of a 5-millisecond spike, reducing peak force by 60-70%. Network switches and routers with 100-200g shock limits also benefit from spring-loaded transport.

Are spring casters used for medical imaging equipment?

Yes. MRI magnets risk quench events and calibration drift from shock. CT scanners suffer detector array damage and gantry misalignment. Ultrasound transducers experience crystal damage from shock exceeding 30g, and X-ray tubes can develop filament damage or focal spot shift. Hospital environments with elevator thresholds and door transitions create repeated impacts that spring casters absorb.

Do aerospace facilities use spring casters?

Yes. Composite structures delaminate from shock exceeding 50g. Hydraulic components suffer seal damage and contamination. Avionics experience solder joint failures and connector damage. Optical systems shift alignment from shock as low as 20g. Transport from factory floor to assembly station, across loading docks, and over rough pavement subjects components to combined shock exposure that spring casters mitigate.

Can spring casters protect precision optics and laboratory instruments?

Yes. Laser systems experience cavity misalignment from shock exceeding 10g. Interferometers develop measurement errors. Microscopes suffer focus drift and stage positioning errors. Optical tables can experience surface flatness changes. Even in cleanroom environments with smooth floors, the extreme sensitivity of this equipment makes spring-loaded casters the appropriate choice for any movement.

What kinds of damage do spring casters prevent?

Spring casters prevent solder joint failures, hard drive head crashes, component lead fractures, and connector damage in electronics. They prevent calibration drift, optical misalignment, and bearing interface wear in precision instruments. They prevent fracture, mounting stress, and internal element displacement in glass and optical components. They prevent composite delamination, fastener loosening, seal damage, and hydraulic line stress failures in aerospace components.

How do spring casters reduce shock compared to rigid casters?

Rigid casters create a direct mechanical path from floor to cargo. When the wheel hits a floor transition or pothole, the force transmits directly to the equipment in under 5 milliseconds. Spring casters insert compliance between the wheel and the mounting plate. The spring compresses and absorbs energy, spreading the impact over 50-100 milliseconds. Peak force drops by 60-70%, which is the difference between component survival and failure.