Measuring casters part 2: Capacity
When we last left our heroes, we’d just learned how to measure the height of a caster. I taught you this not because I fear you may not know how to operate a tape measure, but because I wanted to prove to you that I knew how to operate one. But now that we both know that we know what we both know that we know, we can move one to other things.
The second thing you’ll need to know before ordering your new casters is about how much weight you’re expecting them to hold up. If it’s chair casters, this is a fairly simple (though deeply embarrassing for those of us inflicted with an allergy to gyms) calculation to make: Of all the people how might realistically sit in the chair, which one is … erm … biggest boned?
If you’re building a cart or dolly, then perform a similar guesstimation. Moving a fridge? Rocks? Lumber? Baby seal pelts? (Don’t forget the extra weight added by shame and guilt!) A good rule of thumb is to add a couple hundred pounds margin on top of whatever you think the actual heaviest load might be.
Let’s say you’re building a cart. You work for the local zoo, and you’ve been tasked with the enviable job of moving the rare miniature legless elephants from their sleeping area to the display cages every morning. Each elephant weighs 1,000lbs. Assuming you’re building a fairly standard 4-caster dolly, you’ll divide 1,000lbs by 4 (as the weight will be distributed across each caster). Factoring in the rule of thumb I mentioned above, you’ll probably want four 300lb. capacity casters.
Other things to keep in mind: the compound the caster is made of and the diameter of the caster with both affect how easily the load will roll and what type of environment it will work best in (indoors on smooth cement, outdoors on gravel, in an airlock in zero gravity, on a Civil War reenactment battlefield littered with badly acted corpses, etc). In general, larger wheels tend to work better on rough surfaces, and harder wheels tend to handle heavier loads better.
Wheel and Caster is a locally owned business located in Spokane, Washington. We ship all over the country and strive to provide quick, helpful service. Wheel and Caster is a division of Norlift, Inc, which is also a pretty cool place. You can read more about it at the Norlift blog.