Bearing Alignment Question

[wkps2007]

Hey all,

still working on my design, but as of now I'm leaning toward using two 5-foot shafts as my linear bearings for my x-axis.

Question 1: Is there a way for the software to compensate for minor misalignments, or do I have to use shims, etc to hone the precision of the machine?

For instance. Let's say I run the machine the full length of the x-axis and over the course of say 48", the cut travels 0.100" out of line. Is there a way for me to have the software (mach 3) compensate for this misalignment?


Question 2: What resolution/accuracy is the "minimum" necessary to do wood carving, etc? (I'm thinking of the V-carve program examples) Currently I'm planning on trying for 0.001" resolution by using a 1" x 10 TPI acme screw.

[oldvan]

1) Shims are your friend. Critical if you are as human as I am when making things.

2) Necessary resolution depends on the size of the carving you wish to make. 0.001" is likely to be excellent for many things.

[wireb]

A easy tip is to make both end caps for the X (or any for that matter) identical. When you go to make them (pick your favorite material) clamp the two together then drill all the holes strait though both pieces in one go using a drill press or a plunge router (just to keep the bit square)

Long as your close to square when drilling everything should be dead on.

If your using 80/20 or other "modular" assembly stuff shims and a dead blow hammer will be your friend

[ger21]

1) The machine will probably bind and not move if you had that much misalignment. There is a way for mach3 to compensate using formulas, but they're a bit buggy, and can cause other issues. Best to shim it and get it perfectly aligned. Making the machine work properly is always better than trying to compensate for problems with software.

2) For resolution, you have 200 steps per rotation, which gives you .0005
1/2-10 is really a poor choice, as it will result in very slow speeds. Most use screws with between 2 turns per inch and 5 turns per inch.
I use 1/2-8 2 start, which is 4 turns per inch, and I can easily make movements of .002, and have no issues with very detailed carvings.
One thing to consider, is that your machine will probably flex more than .002"