Instead of using screws, I'd drill holes and use lag/carriage bolts. They're much stronger and you can easily get ones long enough to go all the way through
DIY
Share your self-made stuff and half-baked projects here.
Also check out [email protected]
There is also a related XMPP chat.
Yeah you'll break the wood before having issues with the bolts.
Maybe even some threaded rod with nuts and washers at each end.
4x4 might be more trouble/overkill and money than it's worth for something that only weighs 600lbs? I think you'd be able to get by with 2x4s (+plywood?)and some deck screwed.
This right here. If you have any doubts, go look at a regular wood pallet. Those things can handle thousands of pounds. Some 2x4s and some 3 inch deck screws will do just fine with 600lbs.
Switch to 2x4, make sure the ones on the bottom (known as 'runners') are standing on edge. Then use 3" coarse thread screws to attach the slats. We build them like that at my workplace to ship and store drums of material that are 1600 - 8000 lbs per pallet. So unless your machines are more then 2000lbs per square foot, you should be fine. The important part is to mark the center of gravity, NOT the center of the machine. As long as the pallet is lifted at CoG, it should move around just fine.
I get that 4x4 might be overkill, but the feet on these machines are 3.5" wide, so I can't realistically put them on the narrow end of a 2x4. I'm also ok with overkill since I'm shipping 4 machines worth at least 100k each.
I also can't lift the pallet width-wise since it needs to get through a door that is exactly 8 feet wide. We'll be moving it slowly with two jacks, or a jack and some kind of dolly for the other end.
I'm not paying for it, so I don't care about the cost. I'm trying to get the simplest solution. If I do it with 2x4, then I need cross bars under the feet, and I need to attach the bottoms as well, and I need a lot more measuring and cutting to get the job done.
I see why you choose that method then. I only need to build for forklifts going through large bay doors, so I'm afraid I can't give good advice for the constraints you have.
You're over thinking this. For only 600 pounds, you can just use a regular pallet. Just strap it down with steel strapping, you'll be good.