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Another V-Slot CoreXY Printer

Posted by sdavi 
Another V-Slot CoreXY Printer
December 18, 2014 06:27AM
After building a CoreXY printer based on Zelogik's printer (Atfer Hbot, go to CoreXY.), I decided to try V-Wheels on the X and Y axes instead of Linear Bearings. They are much quieter than the linear bearings which used to rattle a lot, and have printed many many hours with the V-Wheels without any issues. Z-Axis still using linear bearings since it doesn't move much.

Source files available on Github.

Idler End


X-Carriage


Back of X-Carriage also has integrated belt tensioners






Started construction of enclosure inspired by Zelogik's enclosure

Re: Another V-Slot CoreXY Printer
January 11, 2015 05:20AM
Man, I like this implementation very much.
It meets most of my wish list, I was looking for everything inside the frame (except filament spool), spectra drive system and a dual spectra Z drive system like Sli3dr. But this looks like a great place to start from, time to get printing and hacking the scad.
Where are you hiding the power supply? I can't see it in this version or your previous version.
Fantastic work and thanks for sharing.
Re: Another V-Slot CoreXY Printer
January 12, 2015 02:59AM
Supply is currently sitting on a shelf under the printer at the moment while i finish the enclosure. Not visible in the photos, but the Z-axis rods attach to another horizontal v-slot about 100mm up from the bottom. My plan is to put a board in at that height, so there will be a space at the bottom of the printer for a power supply, LCD at the front etc etc so they are out of the heated area of the box and can put some fans in if it needs extra ventilation for the supply. Might even put a little drawer in that space to hold some tools etc.

Good luck with your build!
Re: Another V-Slot CoreXY Printer
January 13, 2015 08:35AM
Awesome!
I was printing out parts for Zelogik's printer but I like the idea of the rollers better. One of the issues I have with my current i3 is the noise! This thing resonates and vibrates like crazy because of the LM8UU bearings.
Re: Another V-Slot CoreXY Printer
January 14, 2015 07:52AM
So nice to see all the small solutions that self-building people come up with smiling smiley

I'm almost done with finishing up my CoreXY laser cutter (planned to be a 3D-printer but I got distracted during the build), and will make a new topic soon with my build.
Currently working on how to finish the belt-tensioning. It's working ok, but I think I should be able to improve on it. Actually was thinking of making double-belt tensioners, so, on both ends of the belt.

Edited 1 time(s). Last edit at 01/14/2015 07:53AM by Ohmarinus.


http://www.marinusdebeer.nl/
Re: Another V-Slot CoreXY Printer
January 30, 2015 07:53PM
Just a couple quick questions on your belts...

Is the outer idler closest to your X and Y motors geared, or the same flanged bearings as the idlers on the opposite side from the motors?

Are your outer X and Y belts twisted 180 degrees? (They're hidden under the XY carriages in the images)
Re: Another V-Slot CoreXY Printer
January 30, 2015 08:54PM
Quote
Grendahl
Is the outer idler closest to your X and Y motors geared, or the same flanged bearings as the idlers on the opposite side from the motors?

They are the same flanged bearings as the rest.

Quote
Grendahl
Are your outer X and Y belts twisted 180 degrees? (They're hidden under the XY carriages in the images)

Yeah I run a twist on the outer ones so most of the idlers have the flat side of the belt running on them, see attached image.
Attachments:
open | download - BeltLayoutDiagram.png (40.8 KB)
Re: Another V-Slot CoreXY Printer
January 30, 2015 09:00PM
Do you find that because you have the outside idlers closest to the motors are riding with the toothed side of the belt on them that you get any artifacts in your printing, or does it not seem to affect print quality at all?
Re: Another V-Slot CoreXY Printer
January 30, 2015 10:10PM
Doesn't seem to affect the quality to me, so I am quite happy to leave it as is. I did once try running a twist between the motor (moved closest to z smooth rod) and the closest idler, quality was the same but the belt started to wear on the edges cause the length of the twist was too short.

There was a discussion about toothed and bearing idlers here: Toothed Idlers love'em or hate'em
Re: Another V-Slot CoreXY Printer
January 31, 2015 07:06AM
Oh come on ! If you're building a core XY printer, that's to get a good quality printer. Maybe it's time to make things properly. My advice : use necessary vitamins with a proper gt2 pulley, a shaft and two bearings. It's not that expensive (<$2) and things will be perfect.


Collective intelligence emerges when a group of people work together effectively. Prusa i3 Folger (A lot of the parts are wrong, boring !)
Re: Another V-Slot CoreXY Printer
February 03, 2015 07:12AM
Actually it doesn't matter if you use toothed pulleys or flanged bearings. Flanged bearings cost me about the same, and I have had great results with them.


http://www.marinusdebeer.nl/
Re: Another V-Slot CoreXY Printer
February 03, 2015 04:17PM
Hmm. What can I say ? Reppapers knows better than laureates in mechanical studies ? Maybe it's good to know the proper way, even if it's always possible to do worse winking smiley


Collective intelligence emerges when a group of people work together effectively. Prusa i3 Folger (A lot of the parts are wrong, boring !)
Re: Another V-Slot CoreXY Printer
February 03, 2015 07:59PM
For some of us, cost and availability plays an important factor. When I was looking at the toothed idlers last year, some places wouldn't ship to my location, and some that did, charge $50-$60 just to ship a few small pieces. Using the flanged bearings works for me (and a number of others) and I am happy with the quality, which at the end of the day is all that really matters. The best thing with most of the Reprap designs is they provide the source files to the parts, giving people the freedom to add/change what they want.
Re: Another V-Slot CoreXY Printer
February 04, 2015 06:38AM
Update: I've added some new files to github to now include an updated BoM, and added an Assembly directory which contains some basic assembly instructions (PDF) and a STL assembly of all the core components together.
Re: Another V-Slot CoreXY Printer
February 04, 2015 07:08AM
Thank you for sharing this sdavi. Which wheels are you using for the X and Y carriages? Are they the recently introduced polycarbonate wheels from Openbuilds? And are they the "full size" or "mini" wheels? Do you find polycarbonate wheels work any better than Delrin wheels?
Re: Another V-Slot CoreXY Printer
February 04, 2015 07:23AM
The wheels I used are the full size ones and yes they are the polycarbonate, these ones: Link. I actually haven't used the Delrin ones before, and the only reason i got the polycarbonate was they were the only ones in stock at the time and did not want to wait.
Re: Another V-Slot CoreXY Printer
February 04, 2015 08:05AM
Thank you sdavi - they are the wheels I'm planning to use so good to know they work well.

I was also thinking about using single sided Y carriages like you have done. I realise you may have done it that way so the enclosure is simpler. But do you think double sided Y carriages would work any better for precision? Or would they just add unnecessary weight?

Like bearwood says earlier in this post, I too am very interested in using spectra for at least X and Y.....and maybe also Z. So I'd love to hear more about CoreXY spectra designs from anyone please.
Re: Another V-Slot CoreXY Printer
February 05, 2015 03:54AM
I initially considered using double sided for the Y-axis (and there is still a back plate module in the source code for it). But after looking through the number of projects on the OpenBuilds website, I noticed that most of them use open ended, even the CNC Routers (although they tended to favour adding more wheels and of course using their aluminium build plates).
Re: Another V-Slot CoreXY Printer
February 05, 2015 04:11AM
Yes - I have noticed that too. Do you think a single sided X-carriage would work too, to save some weight? (Assuming that another way could be found to connect the belts to the carriage)
Re: Another V-Slot CoreXY Printer
February 05, 2015 06:31AM
Yeah, a one sided x-carriage would work, but the x-carriage plastic parts are actually quite light and any weight savings would be low.
Re: Another V-Slot CoreXY Printer
April 12, 2015 11:15AM
Nice printer sdavi ! Do you have example prints to show us ? I also have a question about the belt layout : what would arrive if the inside idlers closest to the motors (circled in green in the attached image) were deleted ? Is it possible to do that ?
Attachments:
open | download - BeltLayoutDiagram.png (31.6 KB)
Re: Another V-Slot CoreXY Printer
April 13, 2015 01:09AM
Quote
Hexag
Nice printer sdavi ! Do you have example prints to show us ? I also have a question about the belt layout : what would arrive if the inside idlers closest to the motors (circled in green in the attached image) were deleted ? Is it possible to do that ?

Removing just those idlers would cause problems, similar to the discussion here: Modified CoreXY.

Here are a couple of small prints (downloaded from thingiverse) I did a while ago in PLA:

Treefrog

Scripted vases

Edited 2 time(s). Last edit at 04/13/2015 01:35AM by sdavi.
Re: Another V-Slot CoreXY Printer
April 13, 2015 03:58PM
Realizing it's purely an aesthetic thing, the one issue with coreXY that bugs me is the belt cross.

Is there any reason not to stack the idlers, and eliminate the belt crossing?
Re: Another V-Slot CoreXY Printer
April 13, 2015 08:12PM
Quote
grat
Realizing it's purely an aesthetic thing, the one issue with coreXY that bugs me is the belt cross.

Is there any reason not to stack the idlers, and eliminate the belt crossing?

Someone has done a modified CoreXY layout at blog.fabtotum.com that removes the belt crossing.
Re: Another V-Slot CoreXY Printer
April 14, 2015 03:14PM
Cool prints sdavi thumbs up ! The resolution looks great.

Quote
sdavi
Removing just those idlers would cause problems, similar to the discussion here: Modified CoreXY.

I've read the thread you linked. So, at the pulleys, the belt should always form an angle of 90° ?
Re: Another V-Slot CoreXY Printer
April 15, 2015 02:37AM
Quote
Hexag
Cool prints sdavi thumbs up ! The resolution looks great.

Quote
sdavi
Removing just those idlers would cause problems, similar to the discussion here: Modified CoreXY.

I've read the thread you linked. So, at the pulleys, the belt should always form an angle of 90° ?

Here are a couple of other relevant threads too: Building my first CoreXY machine - facing a number of issues and Print at an angle.

They will be 90 deg at the pulleys on the gantry, which means the belts will be parallel to the axis of motion.
Re: Another V-Slot CoreXY Printer
April 17, 2015 01:57PM
Thank's a lot sdavi ! Now I understand smiling smiley.
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