CoreXY or Cartesian which is better ?

fcwilt

@oliof said in CoreXY or Cartesian which is better ?:

@phaedrux CoreXY may be easier to build, but it's ultimately (pun intended) harder to square. An ultimaker style sheet-based box printer is more or less self-squaring ...

Can you provide a link to a design like that?

Thanks.

Frederick

mrehorstdmd

You don't "tune" belt tension in a corexy printer. The exact and even the relative tensions of the belts isn't important (of course, you don't want them flopping around and you don't want them so tight that they destroy the motor bearings). All that matters is that the x and y axes are square when you're finished. That's easily verified in different ways depending on how your machine is built. The way most corexy mechanisms are laid out, the belts will be about the same tension when the axes are square.

It can be pretty easy to align the linear guides in a corexy printer if you build the xy mechanism on a flat plate. That's probably true of any other xy motion system, too.

You can design any printer to be easy to align or alignment can be an afterthought, and then you suffer the consequences.

Hiroaki

@mrehorstdmd I understand! Thank you!

Michael Hathaway

@hiroaki I don't use T8 lead screw (too slow), I use Igus high helix lead screws. I will never be as fast as the corexy guys, but I have no belts.

https://youtu.be/I-3kKkkonrs

Hiroaki

@tinken I see, how much is the lead ?

fcwilt

@tinken said in CoreXY or Cartesian which is better ?:

@hiroaki I don't use T8 lead screw (too slow)

Too slow for what?

@tinken said in CoreXY or Cartesian which is better ?:
but I have no belts.

How do you keep your pants up?

Phaedrux

@fcwilt said in CoreXY or Cartesian which is better ?:

How do you keep your pants up?

suspenders obviously.

Michael Hathaway

@fcwilt Who needs pants...

Michael Hathaway

@hiroaki I think they cost about $40 per meter.

I think you are best off with a corexy printer. My printers are expensive, extremely accurate for long periods of time without adjustment. But they are slow, 160mm/s max.

fcwilt

@tinken said in CoreXY or Cartesian which is better ?:

@hiroaki I think they cost about $40 per meter.

I think you are best off with a corexy printer. My printers are expensive, extremely accurate for long periods of time without adjustment. But they are slow, 160mm/s max.

Since when is 160 slow? I limit mine to 90.

Frederick

Michael Hathaway

@fcwilt I bet you could go 300 if you wanted to..?
I only print nylon, so realistically, my maximum is 25-55. To me it's like watching paint dry in Antarctica.

Hiroaki

@tinken Hello No no, My question is the length for one rev of the screw....

oliof

@fcwilt said in CoreXY or Cartesian which is better ?:

Can you provide a link to a design like that?

Ultimaker Original.

MaxGyver

@Hiroaki

In my opinion, a simple Cartesian design is the best choice.

I have come to this conclusion after designing and building 7 high-end printers in CoreXY, Hbelt, Cartesian and Markforged-Style configurations. I have not yet tested the new scurve acceleration feature on a cartesian printer, but I recon it can overcome the added vibration of the extra moving mass.

CoreXY, H-Belt, Markforged etc.

Pros:

Less moving mass

Cons:

Longer belts always add "springiness" to the system
Higher number of belt idlers, that each add a little "wobble" to the system, since even good idlers are often far from running perfectly true
More idlers mean more parts and also higher wear on the belt since it is bend back and forth around multiple radii.
The necessary interpolation of X and Y Moves drastically limit the top speed of diagonal moves
Can take a lot of fiddling until all motors move in the right way

Cartesian:

Pros:

Higher top speed
Belts are as short as possible
Belts are only bend in one direction ->reduced wear
Fewer parts and very simple
Super easy setup

Cons:

higher mass
extra wiring for the moving motor

Hiroaki

@maxgyver Hello.
Thank you for your advise. It’s very helpful !!!

fcwilt

@maxgyver said in CoreXY or Cartesian which is better ?:

Cons:

Longer belts always add "springiness" to the system

Higher number of belt idlers, that each add a little "wobble" to the system, since even good idlers are often far from running perfectly true

More idlers mean more parts and also higher wear on the belt since it is bend back and forth around multiple radii.

The necessary interpolation of X and Y Moves drastically limit the top speed of diagonal moves

Can take a lot of fiddling until all motors move in the right way

Have you any data to back up these "cons"? The last two are particularly suspect.

I certainly have not found these "cons" to make any noticeable difference between my printers.

MaxGyver

@fcwilt said in CoreXY or Cartesian which is better ?:

Have you any data to back up these "cons"? The last two are particularly suspect.
I certainly have not found these "cons" to make any noticeable difference between my printers.

No, these points are only based on my personal experience and should be seen as such.

Right now I am designing a copy of my markforged-style printer but with a Cartesian belt setup, I am happy to share some data when it is finished.

peter247

@maxgyver

So a prusa type cartesian printer is faster than a Ender 6 core XY , EH ?
I think you are the only one who thinks a cartesian is faster than core xy in general.
The question is wrong to start with ? what is cartesian printer ?
In the hobby market a prusa and ender 5 are both cartesian ?

MaxGyver

@peter247

I have experience with neither of both. My cartesian printer is a gantry-style, not a Prusa style "bed slinger".

@peter247 said in CoreXY or Cartesian which is better ?:

The question is wrong to start with ?

Absolutely, the correct answer to the question is: It depends on what you are looking for in a printer...
Print speed, print quality, reliability, cost etc. These are all factors that have to be considered before building or buying a printer.

peter247

@maxgyver said in CoreXY or Cartesian which is better ?:

Absolutely, the correct answer to the question is: It depends on what you are looking for in a printer...
Print speed, print quality, reliability, cost etc. These are all factors that have to be considered before building or buying a printer.

I couldn't agree more and the place to start is size.

The best printer is 2m x 2m x 2m , that will print everything ( Joke )
It is a case of the bigger the print area the more weight , the slower the printer. but if the printer is too small that is more of a limiting factor , so in the end you finish up with 2 printers.
one printer with does all the normally small items fast and one printer for the larger items slow.