OK, I have introduced my initial ideas on the intros thread and already received some really useful pointers.

The plan is (after some advice from you guys!) to build an aluminium framed 3 axis 1500x1000mm CNC router driven by 2no. ball screws on the x axis. In order to drive the 2 ball screws on the x axis I intend to use timing belts, linking them to a single stepper motor.

The ball screws will be either 2005 geared up or 1610. So far I am thinking 2005 because of the potential whip issue over such a large distance.

Having decided to go down the HTD timing pulleys/belts route for connecting my steppers to the screws I have a few querys I hope someone can shed some light. Please excuse my ignorance! - I'm here to learn.


My questions are:

01 which belt width / pitch would you recommend for this application?

02 I am unsure as to how the pulleys will be attached to the stepper / ball screw - do you have any photographs, technical manuals or just a description of how this can be achieved?

03 Is the lateral pressure on the screw and motor shaft likely to cause damage to the bearings?

03 If I mount the steppers through 20mm alu plate will this allow enough length in the motor shaft to connect it to the pulley? if not is there a way of extending the shaft?

04 in order to adjust/maintain tension on the x-axis drive system I intend to use idler pulleys - how do the bearings work for these pulleys?

any images people have of successful arrangements would be really useful as I try to move the design of my machine along.

Thanks in advance!

Joe