[eschaider]

Actually there is another option.

It is possible to build a one piece countershaft with gears that can be slid into position and located with either fastners like spirolocks or simply spacers that position the gears opposite their corresponding driven gear on the mainshaft. A nice colllateral benefit if a gear failure were encountered would be the ability to replace only the failed gear(s) not the entire countershaft.

Another benefit would be the ability to select premium steels such as 4340, 9310 or 300M should you want/choose to. Flexibility would be dramatic, tuning of individual ratios for individual gears would be possible (with individual mainshaft gear alternatives) and the overall strength of the box could be substantially improved.

Ed