Sneak peek of my new printer

[CaptainObvious]

Here's something I've been working on for several months, with some luck I can bring it to life this weekend when I finish the wiring.

The printer is a Core XY type and I included many ideas I had been mulling over for the past year or so:

-It is very compact, excluding the Smart Controller and extruder installation (that later I may place on top) the printer measures 35x35x34 centimeters, with a build volume of 26x22x15/16 (depending on heatbed arrangement); all printers I've seen with similar print volumes are much larger.
-The frame is built using of easily sourced and dirt cheap 19x19mm (3/4" sq.) aluminium tubing, I used a CNC router to drill the holes and trim the tubes to a precise length, all the rest of the structure is printed.
-I used linear rail bearings for the XY axes, very precise, smooth and again compact, in my opinion it's worth the extra price as compared to the usual rods used for this.
-The Z axis is made with three trapezoidal thread screws connected to a single motor with a belt, seems to work well but I need to test it under power. This arrangement allows the bed to be leveled by disengaging the belt and adjusting each individual screw, although I want to improve the "clutch" and move it to the front of the printer for easier access. Originally I was planning to use ballscrews, I tried the arrangement I had in mind but didn't work as well as I hoped.
-The Bowden extruder... I came up with a novel design, it's a bit of a secret for the moment.
-The Core XY belts don't cross at the front, there's a return pulley at each front corner with a tensioning arm, but I also want to improve the design of those with adjustment screws.
-The hotend holder is super light and compact, 3x4x10 cm only, I'd like to experiment with a water cooled hotend later on so I can make it much shorter.
-Compact power supply, 12V and 33A but almost half the size of the ones used normally.
-All the motors, controller and power supply are mounted at the back, so the wiring is kept very short.
-The heated bed will be built in several layers, a phenolic base plate, a layer of cork for insulation, the heating element, an aluminium plate on top and finally the removable glass print surface itself.
-Finally the print area can be enclosed easily, an acrylic divider (cut, not installed yet) will separate the print area from the electronics on the back, there's going to be side and front panels and a door and later on I'll experiment with making lightweight bellows (ie. aluminized mylar and Kapton) to seal the top, this will allow to keep a constant temperature during printing... or at least that's the theory.

IMG_1342.jpgIMG_1347.jpgIMG_1348.jpg

[curious aardvark]

that is a very neat looking bit of kit :-)
As it's a bowden have you considered using a flexdrive ?
http://mutley3d.com/Flex3Drive/

Just looks like it addresses the issue of direct drive weights and bowden feed delay or filament flex.
Saw one in action a couple of years ago and was really impressed with the whole idea.

[CaptainObvious]

After some fiddling I just managed to make a first dry run of the printer, looks very promising! It didn't seem to have any problems moving up to the firmware limit of 300mm/s, it could probably do 400 or more; very quiet too; I'm completely sold on linear rail bearings now.
I was a bit worried about the Z axis, but that also works pretty well, although the calibration is completely out of whack.

Now I have to do the heated bed installation and it's ready for trial runs.

[CaptainObvious]

Got everything working this Sunday, but there's something wrong with the hotend, it takes way too much force to push filament through, making the extruder motor stall and skip; I guess I'll have to replace it.

[hernejj]

Looks like a nice build. I look forward to seeing the completed project.

[CaptainObvious]

First print!

IMG_9120.jpgIMG_9126.jpg

Not too bad, if I may say so myself, the octopus is about 50mm across and every detail of the model is just perfect.
The only issue is the warts all over the model, but keeping in mind that this is a Bowden type extruder and I used the same retraction settings as in my direct drive printer it's actually surprisingly good; besides that seam I can't see any other anywhere on the model.
The second photo has an SD card for scale reference, I'm very pleased with the precision of the printer, I didn't notice the perimeter seam until I saw that photo (over the right eye)

Seems that the hotend thermistor is wonky, I can print at 270 degrees now, but I don't think that's the real temperature; also the print is mirrored in the X axis... I need to to see how to fix that.

[CaptainObvious]

I've been testing the printer the last few weeks and I think I have it dialed down now, today I seem to have arrived to the correct settings to prevent stringing/globing and I can say that the print quality is excellent.

I ran a test to get the right retraction length and speed settings and 4mm at 40mm/s works pretty well, I'm quite happy with the way the extruder works and I'll be uploading the STLs as soon as I organize them.
Here's the test I just did, 15mm high truncated pyramids, 1cm base, 0.5 at the top printed at 40mm/s and 0.2 layer height; have to zoom in really close to spot the seam, let alone any oozing signs.Attachment 9519




Now I'm going to change the hotend for another E3D V6 to check what's the issue with the hotend temperature, the one I have now I have to set it up to 270 C to extrude ABS, either there's a problem with the termistor, the wiring or something else.