waynec
07-08-2006, 11:18 PM
I'm noodling out plans for a remodel on my PR, which will involve replacing the Y carriage unistrut and the Z axis.
I'm considering a beam Y axis that is more along the line of the Tech Isel LC machine with a single cross beam mounted on two vertical endpieces. Theirs is aluminum, but I think I'll use tube steel. In order to keep flex to a minimum, I'll need to space rails on the beam surface some distance apart. ALso, the beam material should be stiff enough to have minimal flex under common loads, with say a 5hp spindle cutting ply goods (a typical task for me).
My questions are
1) I'm thinking a 5" x 2.5" x 1/8" HSS steel tube will be more than sufficient. It weighs about 6lbs per foot, and is several times stiffer than the current unitstrut (thanks Gerald for the steel tube PDF!) The beam will be 7 feet long. IS THIS TOO HEAVY? IS THIS STIFF ENOUGH?
2) How far apart do I need to space the rails on the Y axis beam to get stabil and stiff Z axis? I'm thinking of either Bishop Wisecarver rails, or maybe HiWin linear guides. Obviously the farther apart the better, balanced against the need to keep the mass of the beam reasonable. So, how narrow a beam can I place the rails on and get good performance? Is 5" enough?
Hope these questions are not too difficult to follow. I'm learning to use Autocad, but I'm not quite ready to post a drawing yet.
Thanks for the help!
I'm considering a beam Y axis that is more along the line of the Tech Isel LC machine with a single cross beam mounted on two vertical endpieces. Theirs is aluminum, but I think I'll use tube steel. In order to keep flex to a minimum, I'll need to space rails on the beam surface some distance apart. ALso, the beam material should be stiff enough to have minimal flex under common loads, with say a 5hp spindle cutting ply goods (a typical task for me).
My questions are
1) I'm thinking a 5" x 2.5" x 1/8" HSS steel tube will be more than sufficient. It weighs about 6lbs per foot, and is several times stiffer than the current unitstrut (thanks Gerald for the steel tube PDF!) The beam will be 7 feet long. IS THIS TOO HEAVY? IS THIS STIFF ENOUGH?
2) How far apart do I need to space the rails on the Y axis beam to get stabil and stiff Z axis? I'm thinking of either Bishop Wisecarver rails, or maybe HiWin linear guides. Obviously the farther apart the better, balanced against the need to keep the mass of the beam reasonable. So, how narrow a beam can I place the rails on and get good performance? Is 5" enough?
Hope these questions are not too difficult to follow. I'm learning to use Autocad, but I'm not quite ready to post a drawing yet.
Thanks for the help!