I made the test bench in order to test the threadless ball screw system for position deviation.

The test bench was designed for 6.2T MDF laser cutting.
Please check out the video on Youtube http://youtu.be/NA_9GeFxV0o.

The testing starts from 5:47 on video.

The threadless ball screw carriage starts from X0.0 point, and after some moving, it returns to X0.0 that it checked out by dial-gauge.

The maximum carriage speed was F24000 -> 400 mm/sec.

In a short testing, the threadless ball screw shows big deviation.

I think I have to try to find the reducing conditions of the deviation.

--- Jan 4. 2015 ---
Please checkout following link..
zero-max.com/rohlix-linear-actuators-c-24-l-en.html

they say as follows..
"Positioning Accuracy -- The Roh’lix is a friction drive device and as a result, will show an accumulated error that is, in general, up to 0.002 inches per shaft revolution. Where greater accuracy is required, linear encoders can be used to indicate position."

I think the threadless ball screw system is not good choice for 3D printer without position sensor.

Please save your time. :)

the .dxf files are for laser cutting.

• 20140411_thread_test.dxf is for 6.2T MDF

• 20140411_threadless_bench_cap.dxf is for 2.7~3T MDF

• One of LM8UU linear bearing
• Two of 350 mm smooth lod
• 20EA of M3x20mm bolt
• 6EA of M3x10mm bolt
• 22EA of M3 nut
• Two of ball bearing nut http://www.thingiverse.com/thing:126537/#files