As you noted in your email.

The supplied ACME nuts are: 3/8-10 (2- Start).

Soon!

We have to get them assembled first!

You can loosen up the gantry or the ends a little bit, and then slide the shaft collars on the lead screws out so they are tight. When you tighten up the whole machine, the leadscrews will be tight and tensioned in the machine.

That's awesome!

That is almost always a loose leadscrew (or part connecting to a leadscrew). Check that your leadscrews are pretensioned well, and that all nuts and nut holders for the lead screws are secure. Which direction is the longer (oblong) part on? The X (length of bed) or the Y (side to side on the gantry)?

We are currently working on some improvements to the Z-axis.

We'll be offering CNC Building Blocks 2.0 early next year.

Did you back the project on Kickstarter? Or are you looking to buy just the Z-axis?

Checkout this thread here:

http://www.aquickcnc.com/forums/viewtopic.php?f=12&t=92

There is some information about that about 1/2 way down the page.

I highly recommend using the relay on the board, to trigger an actual relay rated for high power, on its own power cord. The one on the red board will only supply 24VDC, as far as I know.

That would do it.

Do you think you can get the old motor control chip off?

Cut the leads off, desolder it and get a new chip on?