Any time shipping machinery in a box truck, I find it helps to look at it the same as the freight company does. When they (the trucker, the forklift driver, the office dispatcher, everyone) look at your mill, all they see is a cube that weighs "x" amount. If your packaging requires them to look at it in any other way, expect it to be damaged.
In other words, If your box has a handle sticking out the side, no amount of yellow tape will keep it from getting broken off.
The only difference between shipping freight and shipping parcels, is that the former is "expected" to stay upright and be moved with fork equipment, while the later will most likely roll from point A to point B and be moved by hand.
In my experience, 90% of a crates strength is in the pallet and how well the machine is secured to it. The sides are a barrier that establishes the size of the hole needed to fit it on the truck, but don't really protect the machine. I've seen crates with bullet-proof sides with the contents destroyed because it wasn't secured inside or it had a weak pallet that gave way. If your pallet can't be moved with a pallet jack or requires the forks to be positioned some way, expect the crate to be roughly shoved around as the driver tries to cram 100lbs. of stuff in his 10lb. box (which isn't his fault. That's on the dispatcher).
I haven't ever shipped one on a pallet, but anytime I move a knee mill long distance, I drop the knee as far as it'll go so it rests on a wood block (lower COG and takes strain off the vertical screw), and flip the head 180, which often requires it to be tilted front to back too. Taking the table off would save space, but it's really up to you and who's receiving it how much reassembly they want to do. However you decide to fold up or disassemble the mill, measure the widest, deepest, and tallest points on the machine, add 3" to each side as a buffer, and that's your crate dimensions. If you leave the table on the machine, you need to measure from the tip of one handle to the other, for example.
Anything over 1000lbs, I prefer to use 4x4's as the runners and have them directly under the machine with 2x4's on the ends, provided the arrangement allows a 30" wide pallet jack to fit in there. I also prefer to add 1x4 braces under the runners as a little added insurance in case it decides to tip, they'll catch under the forks. 2x4's are too thick and a pallet jack won't roll over them.
When you secure the machine to the pallet, your goals are to keep it from sliding and keep it from lifting/tipping. However you do that via bolts, boards, straps, rope, etc. is only going to be worthwhile if it does those things. I only use lag bolts on heavy machinery (1000lbs+) if there's at least 4" of wood for them to go into, any less I'd rather use through bolts to avoid having it pull through. Use carriage bolts with the nut on top. Any other bolts with nuts underneath will be a pain for the guy uncrating it as the forks will have bent or mushroomed the threads. I'd also add 2x4 cribbing around the base.
In regards to top-heavy machines, or machines that arrive lying on their side, I find that most accidents happen when the crate is going onto or coming off the truck. This goes back to the issue of keeping pallets easy to move with a pallet jack, and understanding the limits of lift gates. Most drivers know them, but the dispatchers not always. Remember that the crate will likely be offloaded and reloaded onto a different truck (think like a layover at the airport), unless you pay for divided service (non-stop ticket).
Putting arrows and messages on the outside of crates (lift here, don't stack) is helpful, but only if you can read it at a glance (I hate those "please please please don't stack me!" cartoons) and be prepared for them to be ignored. If you don't want a crate stacked, make the sides tall enough that it's not an option. The best crates have the weight centered on them and can be easily lifted and moved from any side.
