Originally Posted by tatfiend

Carefully read tcs post above. He clearly describes how to set it up and use it. The adjustment for second gear is the critical one. Get it wrong and you can damage the hub. Choose an index position for second gear adjustment which allows the shifter to fully slacken the cable when choosing first gear and fully tighten it when choosing third. As noted you will need to count clicks for the shift to second gear or memorize the bar end shifter lever position. Not idiot proof but it can work well.

If you read the procedure for adjusting a SA 3 speed hub shifter cable and still cannot understand tcs post then doing your wanted build is not recommended.