I'm looking at making some large machinery moving skates and need some input. I'm starting with a design that our rigger uses.
Each skate has a top plate, 2 axles, 4 rollers and are heavy. The axles start out at 1.25" turned down to fit the roller id. Ihas a chunk of 1.25" thick steel 4" x 5" or so welded between the axles and top plate. The top plate is probably 3/8" steel
His rollers used some sort of off the shelf pallet jack load wheels for his main rollers. IT has a double row ball bearing inside of it I believe. Axles are lets say 1" or 30mm. I want to use a cam follower bearing for the main wheels to simplfy building these things. The cam follower I'm looking at is 3.25" OD 1.75 wide and has a 1" ID Bore. These are yoke mounts that I will slide into onto the 1: axle shaft and keep in place with use of a cir-clip.
I curious about side load (thrust) on these cam follower bearings. When we move a machine we I put 2 skates on the heavy end and 1 skate at the lighter end. This make the machine easy to move just jack up the machine a little and adjusted the 1 skate on the light end and you can make turns no problem..
We have a set of hillman skates that look like little tanks with swivel tops but our last machine destroyed them (too heavy) at 21,500 pounds.
Each Cam follower bearing has a dynamic load capacity of 15,000 lbs so each skate will have 60,000 lbs of dynamic load capacity giving the set of 3 a load rating of 180,000lbs - plenty right.
our hillman set was good for 30,000 lbs all together (4 skates)
Please help with any thoughts or input. firstname.lastname@example.org
Needle bearing cam followers are not intended to carry thrust loads. Have a look at roller bearing or ball bearing track rollers instead: http://www.loadrunners.com/default.aspx
PCI has similar products and are somewhat less expensive: http://www.pcimfg.com/products/rollers/track_rollers.html
I would not count on all the wheels carrying an equal load. Also keep in mind that the floor material is likely to be the limiting factor in load capacity -- I've seen concrete floors get chewed up by tank-type skates. I think Osborn or PCI's literature has info on calculating contact pressure, though it may not cover concrete.
This is what I made for skates. The rollers are 1-1/2" Thomson shaft running on needle bearings.http://www.suscom-maine.net/~nsimmons/news/skate.JPG
What exactly was destroyed?
If your skates were powdered beyond recognition that won't be much help, but if the wheel cracked, the axle bent, or the bearings failed that can tell you what you need to know about a new design.
How are you lifting 10.75 tons? Just curious. You say it like its nothing. I have a mini ram rated at 10 even, but I doubt it would really do it. My press jack is at 12, but again... with the air over its not to bad.
There was a guy on here that sold a nice set of plans for skates. I remember he lived on Florida Gold coast near Canaveral. Sorry, don't remember his name.
On Tue, 19 Jan 2010 14:27:40 -0500, the infamous "Karl Townsend"
Are you thinking about Ron Thompson, who moved to Mississippi?
Weren't some skate designs uploaded to the Dropbox? That or I've seen them here. Google group search might turn 'em up.