I see all these ads for acme and ball screws. Most don't come with end bearings, just the screw and the nut. Some acme/ball screws have non-threaded ends, some look like the thread goes to the end.
1. Do all proper screws have non-threaded ends (both ends) for bearings?
2. Do the bearings just press-fit on the screw shaft? Do you use a rubber hammer to tap them on?
3. Once you place the bearing on the screw shaft then what? Most bearings look very smooth and round with no mounting hardware.
I have heard people say they just drilled a hole for their bearing in their aluminum plate. Are you press fitting the bearing into the plate? That just doesn't sound like it will hold. Is it a tapered precision hole in the aluminum plate? Why doesn't it just fall out?
If you use a "Base-Mount Ball Bearing" then you have some nice bolt holes to mount the thing.
4. If the screw is threaded all the way to the end how are you going to put a bearing on that end? Is that screw useless?
5. If the non-threaded end of a screw is exceptionally long (like 6 inches or more) is it OK to use a compound-miter saw to hack off some of it?
6. Many pictures of ball or acme screws are very bad. The Nook ball screws always show the nut where you can't see any way to bolt something to it. Do all ball-nuts and acme-nuts have a round or square flang with bolt holes?
7. Am I correct in assuming that the non-threaded end of an acme/ball screw with a grooved keyway is for a motor coupler? Some just look like they have a groove for something.
8. Is there any hard and fast rule about the width of the screw? Like a large machine with a screw of 50" long should be at least 1" diameter. And a Z-axis screw should be at least 3/4" diameter for large machines?
9. I'm having a little trouble with my design. Mainly that I have 53.5" THK rails for the Y-axis (side to side), the Z-axis is probably going to be at least 5" wide. Am I wrong in thinking the screw should have 53.5" travel? Or should the minimum travel be larger?
10. Please answer any questions I wasn't intelligent enough to ask. LOL.
Any help appreciated...........Sam
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Questions courtesy of 'Newbies-R-Us'.
