Hi all,

I am building an X,Y,Z robot for my end of year school project. With reference to the diagram attached, can I use the ball screw as a rail and as a linear mover? (normally two rails are used and the ball screw is placed in the middle, but to reduce space I was planning to do it this way). Also, when buying a stepper, what are the specification that I have to keep into consideration?

Thanks in advance.

 

If your tray is sufficiently wide, it could work. Otherwise it is going to bind up.

 

I would tend to use a T shape at the upper end with a linear bearing at each end of the T top.
This would help prevent skew or 'Walking' and binding.
Max.

 

Thanks for the replies. If the distance between the ball screw and the rail is of 1 meter, will this cause extra stress on the ball screw or stepper motor?

 

Any work side loading of the horizontal X? axis would aggravate it some.
If you want to get some idea of the stepper motor drive size, see the Gecko site.
Also sizing here http://www.electromate.com/technicalsupport/?c=kollmorgansoftware
Max.

 

Thanks for the replies. If the distance between the ball screw and the rail is of 1 meter, will this cause extra stress on the by all screw or stepper motor?

Yeah IMO you should reevaluate your design.

 

Also is is usual to make one side non-compliant, the upper side for example, otherwise the two sides have to be Exactly parallel if both are compliant.
Max.

 

See the reprap Mendel at this link.
http://reprap.org/wiki/Mendel_Build_Manual

This design uses two slides and a toothed belt and toothed pulleys (looping one stepper motor and each end of the belt attached to the moving platform.

This design (this device) has become a standard for 3D printing.

 

Yeah IMO you should reevaluate your design.

Like Strantor said.

 

Another option that is growing in popularity is the core xy (like an old-school drafting table). Actually an etch-a-sketch uses the same mechanism.

Here for videohttp://vimeo.com/40914530

One stepper controls x-axis and one for y-axis but the use one common belt.