Which is better... X-Y on Gantry or X-Hot end/Y-Bed

[TommyDee]

Now that I have a little experience with a behemoth printer [CubePro] with both the X and Y axis on the hot end and with direct filament drive [no bowden tube]...

Is there a definitive study out there that outlines the pro's and con's for comparing the two different systems available where the alternative is to move X on the hotend and Y on the bed?

Just a though experiment if nothing else.

[bolsoncerrado]

You mean back'n forth bed vs up'n down bed?

[TommyDee]

That is the other one... but that's Z. No I mean that you move X up high and Y down low... The difference between Cube3 and CubePro.
Moving the hot end v. the table in Z is more of a wash. My thinking is more in the direction flying weight. Z doesn't deal with that to a great extent with the exception of Z-drop for de-stringing which can cause ringing artifacts in your prints as well.

[AllyHarry]

I see. Thanks for the tip, Tommy!

[razor81]

core xy with bowden setup or with nimble (for direct drive) would be a great option... very fast, low moving mass...

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the less mass it has to move so greater can be the speed, look at railcore if you are based in us...

[TommyDee]

You've been thinking about this for a while now, haven't you razor81 However, over time I've answered my own question.

Not only is the moving mass extremely important but there is a lesser element at work here - isolation.
An X-Y stage on the same plane is directly linked and therefore has no isolation.
On the other hand, the over-under X-Y configuration has the vertical beam as isolation.

Worst case; X-Y stage on stilts.

The railcore has one major advantage over say the CubeX/CubePro approach. The railcore uses heavy [relative] side panels to manage sheer. Even a simple cross-brace would help the CubePro a lot. In this configuration, all the mass is up high and consolidated. That means the center of mass for all motion is a centroid.

In the case of independent X and Y motion, your centroid is stationary between the two centers of mass. This adds a twisting motion to the frame rather then radial vectors.

And as for build plate position, another excellent on 3DS' part. The plate should be self-balancing on the carriers as possible. The CubePro plate is like a wagging tongue. Not a plate carriage I prefer. The Cube3 is almost perfect. I'd say the pulley bearings are undersized. Very bold driving just one side.

3DS did design for smooth drivers. Not sure what they intended but it is all over the code. Today's slicers should make Cube3 hardware purr. The only thing the Cube3 suffers from is the hard steps at 200 steps per revolution. That needs updated brains to make use of that. I heard rumor that Cubify was ready to implement routines like that with existing hardware by expanding the F/W control over the steppers.

[razor81]

I dont know what are the drv8811 capable of...
https://www.ti.com/product/DRV8811?u...oCekgQAvD_BwE#

You have to dig in there...

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Looks Like they can only Do 1/8 of the step...

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Thats whats on the cube 3 Board...