CoreXY using Simple parts (printrcore/Smartrapcore)

[etxbkst]

Here's my build of the Smartfriends Smartrapcore CoreXY printer. (http://www.thingiverse.com/thing:651117) Quillford, on github, put together a fork using the Simple. It was a pretty easy build. My biggest hurdle was the firmware Quillford compiled from lincomatic. I couldn't get my homing to work, so I went through several flashes before I finally realized that the z probe logic was in reverse. Once that was corrected, it was smooth sailing. I haven't yet tested the top speed. I hope to get to do that tomorrow.

[Mooselake]

Cool! Keep us updated.

What made you choose this over one of the other designs, say Nicholas Seward's? Iirc RichRap has a core XY design too.

Kirk

Edit: RichRap calls his design , says it's similar mechanism that was used in an old pen plotter design.

[JonS]

Can someone explain to me the benefits of a CoreXY design? I've tried Googling this before but I was unable to find an answer to this basic question.

Thanks!

[etxbkst]

@mooselake, I actually didn't research any other builds. I saw this on /r/3Dprinting, and I figured it was a quick and easy way to try out CoreXY.

I still haven't tested top speed during print moves. I have my travel moves set to 150mm and I have had any issues with that. I was very pleased that my 5mm calibration steps came out nicely with out any sort of calibration. Using this after using a different printer with a heated bed really makes me appreciate that heated bed. I did a largish flat print that curled something fierce. On the side where it didn't curl the print was really smooth.

@JonS, the benefit that stood out for me is speed.

[evanalmighty]

CoreXY is good in that the bed only moves in the Z direction and both the X & Y motors are stationary. This allows for higher speed while putting minimal stress on the X/Y gantry.

[MartyS]

It does have a low amount of moving mass, but as you go larger you end up with a very long belt, have to wonder how calibration holds up over time as the belts stretch. For an XY plotter it really doesn't matter if the 1st and 500th prints are different by fractions of a millimeter, but kind of important for 500 layers of 3D printing...

[JonS]

I'm curious about the stretching of the belt during operation (not just over time). Is this a potential issue?

[DonaldJ]

[mechanizedmedic]

CoreXY gives the weight savings benefits of the H-bot config without any "racking" (the gantry binding between the outer rods). The downside is that the belt configuration requires more complex mathematics than a normal cartesian bot. The Sli3DR configuration addresses both of these issues and uses wire instead of belts.

[MartyS]

Wire! Yes, a lot of old plotters used wire instead of belts. I've been thinking about a way to use belts instead of threaded rod in a mendel type configuration but wire might be better, way easier to design the pulley pathways with wire, hmmmm.....

[DonaldJ]

What version of the Printrboard did you use? I'm muddling through a CoreXY build and I'd like to use the spare clone Rev.D board I have.

And it looks like the Z platform is using a belt and not a leadscrew, correct? How's that working out?