Install a Y-Axis F8 Lead Screw on the Zen Toolworks 7×12 CNC Router

I’ve gone over installing the X-axis and Z-axis F8 lead screws, so now lets check out how to install the Y-axis F8 screw.  One could tear a whole machine up to do this, but after a little thought, the method I used made this lead screw install the easiest of the three.  Check out the video below for most of the steps, explanation to follow.  If you just want to see how fast my ZTW 7×12 is with upgraded X, Y, and Z axes, just skip to 0:32 (original test video at the end for comparison).

To explain the video, in the beginning you’ll need to loosen the set screws on both the driving motor and the collar holding the other side on the bearing.  Remove the circular piece that holds the bearing opposite the Y-axis servo motor.  Once this is done, just roll the lead screw out.  If you have a hand drill available, tighten it down on the end of the screw and reverse everything out. this will speed things up considerably.  After this is out, the Y-table will slide back and forth effortlessly on the bearings attached to the parallel shafts.  It’s worth pushing back and forth for your own entertainment in my opinion.

f8-y-axis-leadscrew-Zen-ToolworksOnce everything is disassembled, your parts tray (I really recommend using one so you don’t loose anything) should look like what you see at 0:16.  Put the new lead screw in under your table, and assemble the anti-backlash nut in place, then screw it in where the old one used to go.  You can then use a drill or your hands to turn the leadscrew where it needs to be, but either way it will go much faster this time (roughly 6.4 times faster).

Parts tray from Amazon.com!

Add a little oil, adjust your motor tuning to 5080 steps per unit, and the acceleration and velocity to 100 (100 is not set in stone) if you’re using Inches.  Try out your new axis, and I think you will be extremely happy.  This was the easiest of the three axes to swap out since none of the structural components had to be changed.  Only a set of Metric Allen keys (ball-nose hex keys – On Amazon – work excellently) and pliers or a Leatherman are needed to do this swap.

A full set of these new lead screws, in my opinion, really take your router up to another level.  Sure, you won’t be holding +-.0005 (5 tenths for you actual machinists) on this machine, but the speed difference is night and day!  For comparison, check out the video below of my router when I first got everything working with the standard lead screws.  It should be noted that depending on the stiffness of your tool and what you’re cutting, you may have to run things at a slower speed than the machine is capable of.

You’ll notice that I’m using a Dremel tool instead of the ZTW spindle in this video.  The Dremel is an acceptable solution generally speaking, but has some disadvantages.  If you’re thinking about building your own CNC router, be sure to check out my article about choosing the right spindle.


  1. The “Fast 8s” Lead Screw Upgrade | JCOPRO.NET - pingback on March 4, 2012 at 11:09 pm
  2. Change your CNC Router Jog Speed with Mach3 | JCOPRO.NET - pingback on March 7, 2012 at 6:29 am

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