Wooden Screw Up

[Petemullen]

My first attempt at cutting a wooden screw for a vise had a few hiccups. The first was even though I was sure I had nailed the settings for my indexer, I was off by a factor of two.
My real question is is there an easy way to unwind the indexer ( B in my case) axis without calculating 360 modulo and doing a ZB command.
Any heel is appreciated.

[tlempicke]

Well here is how I did it and it worked very well. I mounted a pencil in the jaws of the chuck. Issued move commands till the point was vertical and then penciled a line right to the point. Tried my first guess at what the setting should be. Issued the command MB360 from the keyboard. Noted the space and then issued the command MB0 to move the indexer back to the zero point. Now the value was wrong but since I issued it in opposing directions the pencil returned exactly to the mark. I repeated this until I was quite close. Then I issued the command MB3600. The indexer makes ten revolutions and stops. I can find the third and fourth decimal places. It took about an hour but I got the indexer right on the money this way. I also installed a pointer on the indexer so that I can always return to the zero point for the job I am running. I mark the barrel of the chuck with a sharpie and then erase my mark with a little lacquer thinner when I am done.