Quote Originally Posted by JAZZCNC View Post
Ok jonathan you seem to know something all the top Ballscrew manufacturers in the world don't so get on with it and good luck.!!
All the top manufacturers are aimed at industry where the expectancies (life, accuracy etc) are significantly greater. So if we slightly reduce the life by using double nuts or springs with the same preload it's still going to last a very long time. Most DIY builds don't lubricate the ballnut which clearly is reducing the life expectancy similarly to what we're discussing, however they still run for years... I did consider lubricating mine properly, but when you're rotating the nuts it's easier said than done. Even if you could connect the tube for the oil the oil just flys out.
My comments apply to the C7 screws almost all of us buy where the spring helps compensate for the lead error, not your C1 ballscrew!

James: You can check how accurate the square is by placing 4 equal diameter cylinders in it arranged in a square and measure the diagonals (i.e. placing the caliper across the tangents). If they are equal you know it's good. That's fine in theory... the problem is finding 4 accurate cylinders, bigger the better-I don't advise using your router's rails!