Thinking through my first build... and like everyone trying to keep it simple and low cost. I have modified a plunge router in the past so that I could install it in a router table and by modifying the threaded rod, having a simple router lift. Basically I replaced the threaded rod that sets the bit extension so that that I could access it from above the router table. So I wonder, why can't I just turn this upside down to use as a simple z axis.
Hopefully this picture will explain:
A longer threaded rod (which on a Freud is 3/8-16) would replace the stock threaded rod. With a nut at the top of the handle, a turn of the threaded rod will cause the router to "plunge" 62.5 thousands of an inch (1/16). If I built a box around the router and mounted a stepper on top, and hung all of this on the y-carriage, would this work as a cheap and hopefully accurate Z-axis? I realize the travel would be limited to the travel of the plunge router - but this is about three inches or so, which should be enough for me.
Am I missing something that would prevent this from working?
Thanks for the input,
The Elu and Trend routers amongst others have a fine feed adjustment that uses a screw arrangement as an accessory. Whilst the plunging action is of the basic router is a two hands on action the twin bearing rods will bind if the push is applied to one side. Suggest you test the router you intend using by pushing down on one side in the place you intend to mount your motorised 'Z' drive. The other problem is that there are some very tough springs used which you motor will have to overcome and the sliding parts of the router plunge mechanism is not intended for constant use. The amount of use will depend on how and what you are intending to machine. Some machining will use very little 'Z' axis.
I would suggest you think about adding a proper slide for the 'Z' as well as for the other axis. There are threads on this site for the use draw slides for inexpensive mills which might give you some ideas for a first off venture.
Hope this inspires you to have a go - dive in and get cutting - ther is no such thing as a perfect solution!