Seeking advice regarding ballscrews

Hi All,

The plans for my self-designed 3D printer involve using one RM1204 ballscrew for Y and and two for Z axis motion, and an RM1605 ballscrew for the X axis, all on 8020inc linear bearings.
My build volume will be 1000mm x 500mm x 500mm and I'm using 40 series t-slot extrusions from 8020inc for the frame.
I'm wondering if anyone else is going this route, and why or why it may be a good (or bad) choice.

Thanks!

The ballscrews for the X and Y are way too small of a pitch you need high lead ballscrews. Hopefully you have not purchased them yet somewhere around 20 mm per turn or above would be okay. You should be able to find some used on eBay this would be your best bet. You're probably going to need some large motors some people have said they run fine with standard reprap electronics but other people have had problems. I'm going to get grilled for showing this picture again but this is a picture of one I built with ballscrews

Edited 2 time(s). Last edit at 08/24/2014 07:20AM by cnc dick.

Wow! Very cool. Thanks for showing me the CNC stuff - that is quite impressive, and probably more of a long term goal for me.
May I assume you are recommending more lead because the axial motion will be speed constrained?
It was my (newbie) thought that 4mm of lead per turn would allow greatest accuracy and repeatability - am I way off on that?
Thanks for the advice, unfortunately the hardware has shipped, so I'll be moving forward with this configuration. This time.
Cheers

P.S. - I was wondering what the red and green tubes in your photo do - is this printer actively cooled? Why is that plate where they connect spring-loaded?
Thanks again.
Cheers.

Water cooling for the extruder itself spring loaded because of difference in expansion and contraction with different materials and temperature here is a picture of some high lead screws I have laying around

Edited 2 time(s). Last edit at 08/25/2014 04:11AM by cnc dick.

I wish that was my kitchen table.
May I confirm that you recommended using the high lead screws because of the print speed or accuracy?
I expected the shorter lead would allow better accuracy, which is what I was trying to achieve. Is that obviated by micro-stepping?
I apologize for the newbie questions, and if there's a more convenient source for ballscrew information would you let me know?
Otherwise you're going to get too many requests for information or advice from me!
Thanks again!