CoreXY or Cartesian which is better ?

Phaedrux

CoreXY is a lot easier to build than an ultimaker style cross gantry. I'd say it's hard to beat in general for a good all around printer.

fcwilt

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

@hiroaki The less you move the bed, the better. Linear rails is a plus. My new printers have lifting/flying gantry with a solid non-moving bed. I have all screw drive with no belts which I think is better, but that is debatable.

Ya gotta love it.

My current favorite printer has all belt drive.

I guess these differences are what keep life interesting.

fcwilt

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

CoreXY is a lot easier to build than an ultimaker style cross gantry. I'd say it's hard to beat in general for a good all around printer.

I can see that it is easier to build - with the cross gantry system getting everything lined up just right so there was no binding took a bit of fussing and cussing.

Now I'm no expert and I have seen the math on the different kinematics but I let my eyes glaze over and move on to something else.

My "MarkForged" style printer with the two Y steppers seems to avoid the racking issues folks talk about. What I like is that the belt paths are are shorter even though it takes three belts instead of two as in a CoreXY.

I've got a couple of Chinese CoreXY kits that have been sitting in boxes for a year or more - perhaps I will decide to re-visit the design.

Hiroaki

@fcwilt I agree! Thanks

Hiroaki

@fcwilt I have thought about to make one with lead screws(or ball screws) . But when I calculate the travel speed between belt drive and screw drive, and also wear out of the screws, I gave up making one. What is the lead of screws of yours? I feel that with the belt drive, it goes too much and with leadscrews it goes too small....

o_lampe

@hiroaki
There are leadscrews with 8mm lead. They'd be faster, but IMHO also wear out faster and need stronger motors (higher risk of loosing steps).
I went for ballscrews right away, but not for XY axes. They run easier and don't wear out fast.

oliof

@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 ...

o_lampe

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

CoreXY may be easier to build, but it's ultimately (pun intended) harder to square.

Do you talk about belt tensioning?
TBH, I made up an easy to implement "belt tension-equalizator". But never felt the urge to implement it.
Lazyness: 1
Difficult to square: 0

oliof

@o_lampe no, I mean getting the frame square, especially when using aluminum extrusions. Belt tension is another issue, looking forward to see your fix (-:

fcwilt

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

@fcwilt What is the lead of screws of yours?

I don't understand the question. The one printer I mentioned, in response to your post about having all screw drive, has all belt drives.

Frederick

fcwilt

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

@o_lampe no, I mean getting the frame square, especially when using aluminum extrusions. Belt tension is another issue, looking forward to see your fix (-:

What do you think about the E3D motion system in that regards?

Thanks.

Frederick

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.