Indexer B Zero

[waynelocke]

Does anyone have an accurate method of zeroing the Z axis? It usually doesn't matter but sometimes I need to get back to the exact position. I avoid it now and just don't use the SB again or turn it off if I know I am going to need to remachine something.

[Gary Campbell]

Wayne...
Do you have a square face left on the blank? If so, I have used a machinists square from the gantry to one face of the square (and mark which one).

You can also use the same process to a flat surface under the indexer.

This should allow you to get very close. See attached rotary class slides

[myxpykalix]

Here is a simple jig for getting zero on your indexer. Take a 2x6 piece of wood. Set it on edge of your rails for the indexer. Press it against the tailstock to make an indention in the wood.Draw a line across where the indention is and cut your wood to that height. You now have a surface on which to zero to that is at the center of your indexer Zero.

[Gary Campbell]

Jack brings up a good point, I assumed the OP wanted the B (indexer) itself zeroed. If looking to zero the Z to the indexer axial center, use the method shown in the picture below.

FYI: the syntax for ShopBot would be: VA,,,2.036

[waynelocke]

I have a Zero routine which zeroes to the top of the tailstock. I am wanting to make someway to repeatably zero the B axis. I don't always have a square side left and I am not real secure in trusting a square to the piece to accurately locate the zero. As an example, here is a shot of a piece with an inlay on a taper. The inlay had to be done in two separate cuts. One for the blue and the other for the brass after the blue resin was dried and flattened. I did not leave a flat because I squared everything up before turning.http://www.talkshopbot.com/forum/attachment.php?attachmentid=29631&stc=1http://www.talkshopbot.com/forum/attachment.php?attachmentid=29632&stc=1

[Gary Campbell]

Wayne...
I have used prox switches on some of my custom rotary's to allow setting a rotary zero. Not that hard to rig up.

[waynelocke]

That's what I'm thinking about Gary. I was thinking about using a solenoid activated actuater which I could activate in the routine and then have a target on the shaft which would swing around and make contact. The zero routine would be like the ZZero routine. Maybe the proximity switches are the way to go.

[waynelocke]

Gary,
I have a proximity switch mounted. How can I have the software make the sensor active during a zeroing routine and then turn it off? I know it can be done but it escapes me. I thought about just putting a manual switch and a push in the routine to activate it and deactivate it.

[Gary Campbell]

Wayne...
You can either use a switch on the + side of the prox switch, even put it on an output if you feel a need to turn it off. If you set the B limit input [VN] as a standard switch, you wont need to turn it off as your zero routine uses the state of the switch to stop movement. It will not cause a "limit hit" when set as a standard switch

[waynelocke]

Thanks Gary. I didn't realize that. I thought that it would stop every time it was triggered. Thanks for lifting out of my ignorant bliss. I was going to start with the X< Y Zero routine and modify the file. Thanks for all of your help. You greatly simplified what I am doing.

[Gary Campbell]

Wayne...
Don't forget to adjust the move speeds appropriate for the B axis