I'm in the process of building a workbench and an assembly table for my shop. Mobility is key to my operation. I'd like to put retractable casters on them. I'm not finding much available in the form of bolt-on, side mount units. The only thing that even comes close is an item that Woodcraft carries designed for a contractor saw. Has anybody else solved this?
From contributor B:
Don't know about retractable casters, but you may want to take a look at Zambus casters (zambus.com). These are leveling casters, and the leveling foot can be turned down to transfer all the weight to the leveling foot. I have all my equipment and work tables on Zambus casters for the same reason you mentioned. A set of four Ac-300 (660lbs per caster) runs about $140 with shipping.
I admit that my expectations are perhaps a bit high. Mobility is almost a universal requirement in a shop. And workbenches arenít terribly mobile. Go figure. I thought that the industry would have seen a market for this, and responded to it. The suggestion regarding the Shopsmith caster set was something like what I had in mind before I posted this question. Why? I first got into woodworking over twenty years ago, and my first machine was a Shopsmith Mark V. It had an optional retractable caster set accessory. Twin casters mounted on a common axle with spring-loaded cam detents. Stepping down on the lever rotated the axle, rotating the cam, pressing the casters at either end of the axle down, lifting one end of the machine. Simple, easy to use, and out-of-the-way. The drawback: they were light duty, as the SSMV wasnít a heavy machine. These donít lend themselves to being adapted to a workbench application.
Necessity and frustration are the mothers of invention, right? So, I adapted/upgraded the Woodcraft retractable caster set (PN 141550) as follows (any Woodcraft product engineers in the reading audience please take note):
1. I removed and replaced the original light-duty caster wheels with a 3Ē Fairbanks swivel caster with threaded post units. Weight capacity 125 lbs.
2. I replaced all of the original softer boron steel bolts with beefier SAE grade 8 stuff. Note: the retractable caster action is actually made of pretty decent stock. The bolts were a different story, hence replacement.
3. I milled a set of wood shims which I glued and screwed to the legs of my workbench. This created the amount of mounting surface required to securely bolt the retractable caster set to the bench leg.
So, for about $75.00 (the cost of the Woodcraft stuff, the replacement casters, and the replacement bolts), voila - retractable casters that'll lift 500 lbs or so.
Lastly, to Woodcraft product engineers (or to any other caster engineers looking for a fresh idea), a couple of suggestions from a guy that would prefer to buy this stuff rather than to have to fabricate it. Remember custom fabrication is time away from running the business - lost revenue, lower profit.
The retractable caster set consists of three parts:
1. The steel mounting flange which is bolted to the retractable caster action.
2. The actual retractable caster action.
3. The caster wheels.
Consider making 4 or 5 different mounting flanges which can be mated/bolted to the retractable action. The design of the various flanges would allow them to be engineered to fit various types/styles of equipment. This is what I was originally thinking of doing, but didn't because it was a pain to shorten the length of the bench legs to keep it the same height as the rest of the surfaces in my shop, and because it was easier to fabricate the wood shims, than to fab a steel boot that would slip over the leg of the bench.
Easy pickings here guys. Little additional engineering costs. Stamped steel flanges will add only pennies to the product cost. The stronger bolts, likewise, are low cost additions. The market is huge. To my knowledge, nobody has a universal mobile base for workbenches and assembly tables. This is your customer calling. Step up. Make it, and we will come...
Comment from contributor A:
Retractable casters: some excellent ideas have been floated here. I particularly like the hinge and block caster concept. Donít throw out the use of those Shopsmith caster sets though. Their weak link is the heavy rod the tri-peddle is attached to. By cutting both rods and extending their lengths for a wider work bench design, I then welded an additional solid rod, then welded 1/8" plate about a 1/2" wide webs across the full length at 120 degree offsets for three webs per rod, giving the rotational rod serious extra strength to properly rotate the mechanism without undue flex. Each set can now lift a 500 lb table easily at an additional design width of over 30". The original wheels are iron, and can take the loads. Everything else about the Shopsmith wheel housing is beefy enough too, no other upgrades are required.