Hello all,
I have been tasked with building a 1 meter X 1 meter Cartesian bot. I already have some experience in building 3D Printers, so I had assumed that I can just use 1 meter lead screws and smooth rods and be done with it. But I was so wrong. Soon I discovered that lead screws are not fast enough and smooth rods(10 mm) might sag.
I have already spent few hours reading many posts on the forum and learned a lot regarding ball screws, R&P, linear guides etc. I am confused between what to choose. I will list out the specs of my future machine:
X-Y axes length - 1 meter (Z axis not required for now)
Payload - 1 to 5 kgs(2 to 11 pounds)
Accuracy/Resolution desired - 30-50 micron(0.001' inch) [I arrived at this figure by taking average of accuracies offered by a Rolled C7 Ball Screw and a industrial Cartesian robot)
Speed - 1000-1500 ipm [ This is the speeds what a Industrial Cartesian robot offers]
There will be no forces acting on as it does nothing heavy and will be used for glue dispensing.
I am torn between ball screw and Rack & pinion. Does the price of a Ball Screw justify in a machine with no heavy loads? I am leaning towards R&P but still haven't found anywhere in the forum what is the actual accuracy offered by it. And then I also discovered that you can't drive the pinion directly and need a 3:1 reduction.
Second doubt is of linear motion. Will 16mm linear rods with bearing blocks suffice or linear guides are necessary?
For driving both the axis I will be using NEMA23 motors having 19 kg-cm torque.