Zeroing A & B axis?

[William Couie]

I just purchased, received and have setup my first ShopBot Desktop Max with a 6" Rotary Indexer. I have installed everything and read all the documentation but am not sure how to physically zero the A & B axis properly. I have learned that the "B" axis is the rotational axis around the X axis and the A axis is the rotational axis around the Y, (is that correct?). I've read through a multitude of posts but haven't came across one that instructs me on proper zeroing. Does anyone have a link to proper instructions or perhaps can you post this procedure so a newbie to indexing can accomplish this? Thanks for any info and/or assistance in advance.

[Brady Watson]

ZB zeros the B axis, which on a SB is always the rotary regardless of orientation. The A is usually reserved for a 2nd Z.

For rotary work I'd recommend zeroing the Z at the center of the rotary axis. You can make yourself a custom zzero routine to offset for the indexer.

-B

[William Couie]

I have already created a jig for zeroing at the center of the rotary axis. Good advise. Makes things much easier. Where do I place my spindle and bit prior to zeroing the B axis? I'm not understanding the B zero procedure. Unsure of what configuration I need to be in prior to clicking/selecting ZB.

[coryatjohn]

It doesn't matter where you place the spindle prior to zeroing the B axis, as long as the point lines up with the center of the rotational axis of your indexer. I have a chunk of 2x4 that I stand next to the work on the indexer mount that lines up with the center. To zero, I back off the X axis by 2", zero the B, then move back to the "zero" position. My indexer is oriented on the X axis and the gantry moves the Y car only.

If you examine an indexer machine code file, the axis your indexer is oriented on doesn't even have a number. It's blank. As I am on the X axis with the indexer, all X axis values are missing from the machine code. That means that it is irrelevant what value the X axis reads on your machine when you are doing indexer work. I zero the Y axis about 2" away from the chuck. It is very important NOT to run your end mill into the chuck. It can be a costly and embarrassing error. Don't ask me why I say this.

[William Couie]

Perfect. Thank you for breaking it down for me. I was beginning to think I was going to be required to climb a mountain in the Himalayas and offer sexual favors to some monk to be worthy. LOL. That’s just what I needed. I figured because the axis is 0-360 degrees that it would be the proper position. Thanks again for helping out this neophyte. Can’t wait to begin now.

[coryatjohn]

Don't forget to post pictures! (not of you and some monk, but of your work!)

[William Couie]

LOL. Looking forward to it and thanks for the help!