CoreXY or Cartesian which is better ?

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.

deckingman

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

It is a case of the bigger the print area the more weight , the slower the printer..........................

It never ceases to amaze me how this myth propagates. It generally goes along the lines that higher mass needs more force to accelerate it. Therefore, for a given motor torque, a lower mass can be accelerated faster. But that completely ignores the fact that what really limits print speed is not how fast the hot end can travel though space, but how fast one can melt and extrude filament. It is a constraint that cannot simply be ignored. Much like a Ferrari might be capable of much higher speeds and accelerations that say a Fiat 500 but on the school run, where both vehicles are constrained by the same heavy rush hour traffic and speed limits, the Ferrari won't do it any quicker than the Fiat, regardless of what it might be capable of without those restraints.

For info, by feeding 5 filaments into a 5 melts chambers using 5 extruders and a mixing hot end with a mixing ratio of 20:20:20:20:20, I was able to achieve a melt rate in the order of 45mm^3/sec which allowed me to print at 300mm/sec using a 0.5mm nozzle and 0.3mm layer height as documented here in October 2018 https://somei3deas.wordpress.com/2018/10/14/real-3d-printing-at-high-speeds-and-even-higher-melt-rates-with-a-large-nozzle/

What may surprise you is that a 5 input Diamond hot end, slung between two parallel rails has (in my case) a moving mass in the order of 2Kgs in the Y direction, and that above tests were accomplished with Nema 17s running at 1.8 amps and using CoreXY kinematics. To this day, I still use 350mm/sec non print move speed (even though I rarely print at much more than 100mmsec).

peter247

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

It never ceases to amaze me how this myth propagates. It generally goes along the lines that higher mass needs more force to accelerate it. Therefore, for a given motor torque, a lower mass can be accelerated faster.

I don't think that , it is more to do with the mass deaccelerating and newton law on the conservation of energy.
The more the mass the more ghosting you have to deal with at a fixed speed , Using your example if you have a 2 ton 4 wheeled drive V a fiat 500 on a head on crash the one with the most mass wins .

deckingman

@peter247 Sorry mate. You said quote " ...........the more weight , the slower the printer". That is a sweeping statement and the one which I was refuting. So you can't now turn around and say (quote) "I don't think that".

Also, how on earth do you arrive at this statement - quote "The more the mass the more ghosting you have to deal with at a fixed speed" ? Please elaborate the logic behind that statement. Given that the resonant frequency of any object is inversely proportional to it's mass, I'd say the opposite is true.