Switch to horizontal dual x linear rails?

Okay so my corexy stage looks like this, it began as a smartrapcore alu:


Recently switched from 8mm rods (vertically stacked on x) to linear rails.

It prints well (running on re-arm now) but I'm thinking about trying dual horizontal x-rails to have no cantilevering of the hotend/extruder. I will end up losing a bit of y build space.

How much of an improvement might I expect? Anyone made the same change care to comment on what effect they saw doing this?

I just can't quite decide if the improvement will be too marginal to be worthwhile or not. Its only one rail and some redesigned y-carriages, and an x carriage.

Edited 3 time(s). Last edit at 04/30/2017 10:45AM by DjDemonD.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

Do you have play in your rails/carriers? Where does the cantilever effect come from?

What if you'd put two rails back to back? Their carriers would be 26mm apart ( with MGN12 ), which is plenty IMHO.

There's no play in the rails, or carriages, its just with the configuration I have its almost impossible not to have a slightly wobbly nozzle as there is a lot of printed parts between the x rail carriage and the hotend. If I made one solid metal bracket it would be much less of a problem. I like your back to back idea that could work.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

If the bearing block itself doesn't wobble (it shouldn't, unless you got cheated when you bought the linear guide), work on fixing the cause- print better parts or replace them with better fitting metal equivalents. Throwing another linear guide in might fix the problem but it will definitely increase the Y axis moving mass.

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Ultra MegaMax Dominator 3D printer: [drmrehorst.blogspot.com]

Agreed, a metal bracket is the answer.

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Simon Khoury

Co-founder of [www.precisionpiezo.co.uk] Accurate, repeatable, versatile Z-Probes
Published:Inventions

I imagine the flexing is happening in the Y axis brackets, where the pulleys are secured rather than the extruder gantry...

You could also minimise movement in the nozzle by bringing it closer to the centre of rotation (ie, the linear rail block), so if there is flexing from plastic parts it will not be as severe. A shorter hot end might help quite a bit (e3d aero maybe?).