26

Re: Thoughts on extending the Da Vinci Jr

ok I tried to use that but I run windows so it doesnt work. I see he says to install strawberry perl, but I dont know how to config that to let it run

Sd4 #9080 with a glass bed. E3d chimera duel extruder. Paste extruder , duet wifi.
Lawsy carriages. linear bearings. Y axis direct drive, Kinect scanner
SD4#8188 glass bed, lawsly carriages, E3d v6, octoprint http://www.ustream.tv/channel/hotrod96z28
Filastruder/filawinder, Custom Delta 300mm x 600mm

27

Re: Thoughts on extending the Da Vinci Jr

You might be better off using Cura for now anyway. It did *much* better both positioning the wipe tower, and I like how its wipe tower works.

With Makertum's script, being hard to configure, it's not easy to move the wipe tower where you want it. When Ooze Prevention was on, too, it misordered the nozzle temperature changes and let the active nozzle cool while heating the inactive nozzle. And it also liked to purge both nozzles before starting a new layer, which only meant that T0 (say, white) got purged, then T1 (orange) got purged, and then it started printing with T0/white. Too many tool changes that left too much room for oozing.

Cura here, while I'm not partial to it otherwise, did a great job. It only purges the active nozzle when making a tool change, so it's a bit quicker to start printing after purge, and it automatically positions the tower near the print.

http://soliforum.com/i/?mtzcnc7.jpg

28 (edited by Anthem 2016-09-11 01:29:23)

Re: Thoughts on extending the Da Vinci Jr

Guys, I just printed my first piece using PVA supports. And it is AWESOME.

http://soliforum.com/i/?UulcMXW.jpg

I designed a window for my kid's Lincoln Log set since I couldn't find one on Thingiverse premade. And thinking about it, this would be a really hard piece to print. It's almost all negative space and there's no way to turn it to get it to support itself. Normal supports could work but there'd be a lot to remove, and the piece itself has very thin walls so you'd have to be extra careful not to break it.

I printed this using Cura with PVA in my second extruder. A few hours later I dropped it in some warm water, and with a little rubbing I had a nearly perfectly shaped print.

http://soliforum.com/i/?rHrUbe8.jpg

(Original on the left, mine on the right, obviously. I'm really starting to hate translucent filament -- it's so damn ugly.)

I had some concerns with the PVA when loading it up because it's super soft, and I wondered if my extruder would handle it. The stock DVJr extruder did fine. Just make sure you never over-extrude PVA by accident, because it'll curl inside the extruder and might get stuck (I almost had this happen -- I loaded it a little too far with the hotend cold and it started to curl, but I managed to pull it back out and straighten it). I don't think I'd try using it with my 3maker All-metal extruder, because the springs on that thing are SO tight it'd probably crush the filament before it even got to the bowden tube.

Thing: http://www.thingiverse.com/thing:1764401

29

Re: Thoughts on extending the Da Vinci Jr

Me again. Just posting my latest status.

Printing with PVA supports is awesome. Until it gets wrapped around your extruder. I'm thinking I might have to switch to a direct drive for this stuff, as it's a lot softer than I expected. Otherwise I haven't done a ton of dual extrusion lately but the setup is otherwise doing fine, and I haven't even lost any print volume.

I have however been working on my Y axis upgrade. I have the rods and bearings mounted on part of my printed frame, and I think I have a plan for mounting the glass and endstops. I have idler brackets printed and all the other supplies in hand. I need to print a few more pieces of V-slot for the frame, finish up those other little items, then I'll be ready do to a bench test. I'm expecting to have at least a 500mm Y axis when this is all done big_smile

30

Re: Thoughts on extending the Da Vinci Jr

I am just about overjoyed right now.

I've been having some occasional problems with extrusion from my new 3maker All-metal extruder. I'd begun to suspect that it was a problematic design for three main reasons:

  • The tension springs are SUPER hard. I can barely squeeze them hard enough to release the filament and pull it out, and I'm not generally a weak guy.

  • There's a huge gap between the point where the bearing and gear pinch the filament and where the exit hole is. This makes it really, really hard to load new filament because even the slightest bend or angle going past the gear will make it miss the exit hole. This gap is at least the radius of the gear. This also makes it totally unsuitable for printing softer filaments like PVA.

  • The gear is just a straight grooved gear. It's not recessed like the Mk7 or Mk8 are. This makes it extra hard to line the filament up on top of the big gap, and I have my suspicions that it doesn't grip very well to begin with (maybe that's why the springs are so hard)

My extrusion problems have been occasional, but once in a while I get either a stripped patch of filament, or just tons of slippage. I began to think that the pressure of the springs was causing more harm than good and making the extruder slip prematurely.

My solution? This thing: http://www.thingiverse.com/thing:1679553

http://soliforum.com/i/?kDulg5X.jpg

I originally built it because it's supposed to be better at printing softer filaments (like PVA, which I've been having trouble with). It uses 40mm M3s to provide the tension instead of a spring, so it gives you extreme control over the pressure applied to the filament. The downside (which I have yet to test out) is it probably requires some re-adjustment when switching materials.

But recently I've become interested in optimizing the speed of my printer, or at least understanding where the speed limitations of my printer originate. See my related thread on that topic here: http://www.soliforum.com/post/127090/

Anyway, after performing some very careful adjustment of the tension screws, I'm printing a test piece at 150mm/s -- successfully! That's nearly 20 cubic mm/s!

Compared to my speed test results yesterday using the 3maker, I've literally quadrupled my maximum print speed.

I *highly* recommend this design. I have yet to test it out with PVA, but I'll do that soon and let you know how it works out!

31

Re: Thoughts on extending the Da Vinci Jr

Y-axis extension, nearly complete! All I need is to get a new piece of glass for the top -- I'm actually thinking of going with acrylic, but I need to do some shopping.

Anyway, it's installed and working but using the stock 165mm glass plate for now. Here are some photos!

http://soliforum.com/i/?dPqeYs9.jpg
http://soliforum.com/i/?1ZADPnx.jpg
http://soliforum.com/i/?VCKvFaq.jpg

Leveling the bed is currently rather difficult, so I'm thinking of printing some new parts to make that easier (maybe using the new larger bed size to help me bootstrap this mod by printing longer brackets for the bed mounts including built-in leveling screws). However I managed to get it leveled enough that it still prints decently.

This axis assembly also is about 6mm higher than the stock axis, which is fine, but means you have to be extra careful about homing and moving axes (or at least being smart about setting your MIN and HOME_POS values in the firmware). The bed is now high enough that it can crash into the X axis if you're not careful.

I'm sure I'll be tweaking this for another week or two, so I'll keep you all posted, and I'll make sure to post photos when I have the new glass installed.

32

Re: Thoughts on extending the Da Vinci Jr

@Anthem - Brilliant! I thought that my Jr looks hacked but yours is quite something (all that is in a good way).
Actually I feel quite sentimental now - remember that day when you unpacked your Jr and peeled all that protective film for the 1st time, so innocent! smile

33

Re: Thoughts on extending the Da Vinci Jr

Hey guys. Finally I've done it! I have a 425mm Y axis!

http://soliforum.com/i/?npScpxi.jpg

It's been a long time coming. It can be hard to find time to work on this thing, but finally it's done.

I designed and printed new bed levelers for three-point knob-based manual leveling, which works well, but you have too be careful about knocking them out of alignment when removing pieces from the bed. But it lets you tweak your Z offset in the middle of printing, which can be handy for the first layer.

http://www.thingiverse.com/thing:1826941

I'm using 5.6mm acrylic as my bed material, with my usual painters tape on top. The piece of acrylic I got unfortunately is not the best, as it warps slightly toward the ends by a mm or two. I might eventually replace it with glass if I don't think weight will be a problem, or just find a better piece of acrylic.

There Is room to squeeze a few more centimeters out of this axis. The bearing mounts take up nearly 100mm by themselves, which I might be able to shrink down, but I worry it might destabilize the bed along Y too much. Besides, 425mm is definitely enough for me right now smile

34

Re: Thoughts on extending the Da Vinci Jr

@Anthem - Well impressed. Now I'm looking forward to see some of the prints utilising whole bed size. Recently I've built 450mm Z height machine - printed a rocket for my little one (vase mode) - that feeling when you remove massive print is one of the best feelings! Not like I'm giving you any hints! wink

35

Re: Thoughts on extending the Da Vinci Jr

Hey guys. It's been a while.

Nothing much new from me on this topic itself, because after my Y-axis extension (which is working great so far) I've made some decisions about where to go from here.

First off, with the holidays and impending visits from out-of-town family coming, I'm going to have to shuffle my 3d printing stuff off to the basement soon, which likely means less chance to work on the machine when the whim strikes.

Secondly, I can't complain about my not-so-Jr anymore now that I have a giant new axis. I've been thinking about the Z upgrade and realized that if I'm going to bother with that, I might as well redesign the X as well since so much of X depends on Z. If I did that, Is end up tearing the frame apart, putting it back together, and having enough pieces left over that I could practically rebuild the Jr from the leftover pieces.

So instead of doing that, I've decided to keep my not-so-Jr in its current working state and start building a new printer.

Actually, two.

I'm currently printing pieces to build a Dollo (an extensible mostly-printed machine with no metal frame), and I've begun design work on a giant machine based on 2020 extrusion with gantry movement using 600mm rods in all three axes.

The Dollo is coming along. I print two extension pieces every night since they take the longest, and by tomorrow I should have half the frame built.

My own design is coming along nicely too. I have most of the XY movement designed out in OpenSCAD already. It's only down to the belt/bearing retainers and endstop mounts. I'm planning to use perpendicular 8mm rods to mount the hotend (I've heard that aluminum ones can be had to make this lighter), with a lowering Z axis, and I plan to design a quick release hot end that shold be easy to change out or remove without losing calibration (maybe swapping for a Volcano?). Overall I'm hoping to achieve a build volume of at least 1/8 cubic meter (500x500x500mm).

I have ideas, but haven't SCADed the Z design yet. It seems straightforward compared to the XY. The tricky thing will be printing some of the crazy pieces I've designed for the motor mounts smile I may yet break them up for easier printing, but we'll see how this goes.

36 (edited by Anthem 2016-11-11 05:11:25)

Re: Thoughts on extending the Da Vinci Jr

Oh, and by the way, I've been working on the side on adding two more extruders to my Jr for a total of four colors, using "flux capacitors" as I've heard them called -- Y-shaped printed splitters that let you retract one color and extrude another.

reprap.me sells Stepper Expander boards for upwards of $25 US, which is pretty steep considering it's a PCB with not much more than one resistor and two capacitors. Compare that to a $10 pack of 5 stepper drivers and a $5 breadboard.

Anyhow, I have the wiring figured out and have tested them directly on an Arduino. Next step will be to hack the Marlin firmware to add support for four extruders using only two hot ends.  It's been done, particularly for the Diamond hotend, but I haven't yet gone through the diff against my customized firmware to find out what they modified. Probably I just need to flip some preprocessor defines. It's easy to use two thermistors with four extruders, but I found that Marlin doesn't know what to do with only two heaters and it assigns #3 and #4 as owning the heater pins instead of sharing them with #1 and #2, so an attempt to start printing just results in the dreaded HEATING FAILED.

37

Re: Thoughts on extending the Da Vinci Jr

@Anthem - Don't want to influence your decisions or so, just feel obligated to share my experience so you can probably better prepare etc...
I've attempted to build 500x500x600 machine once (I had this "future vision" of 3D printers becoming yet another "white appliance" in the household when instead of ordering stuff and waiting for delivery man to come you order and print it instead, anyway... Idea isn't dead, I'll get back to it at some point, it's simply temporary off my to do list for now...)
So build. I went with CoreXY which seemed to be logical move to achieve build volume that size in regular "white appliance" form factor. Also worth to mention that key idea was to build it as cheap as possible, with design around widely available parts.
I went with 8mm stainless steel rods all the way (4x for XY and 4x for Z), 2x 45Ncm Nema17 for CoreXY and 2x 59Ncm Nema17 for Z.
For the build plate I wanted to use aluminium sheet (so I could use inductive probe for Z levelling and probably have it heated - about that later). It was impossible to find dead straight, thin and light aluminium sheet so I ended up using side panel of my old MacPro! wink It's 3mm thick therefore light enough, ok it reduced build volume down to 400x 480 - close enough, and good enough for the prototyping stage (btw you can score old G5 for peanuts these days).
Assembled everything and had my 1st dry run successfully. Then thought I need to see if Z axis is able to lift bed with presumably full bed plate print aka 500x500x600 solid block. Weight of solid PLA cube 500cm3 is 625g so roughly 1kg if you add missing 100mm of print + missing aluminium of build plate if I find 500x500 alu sheet in the future + potential heater element.
Aaaand... Nope... It was able to lift it down but not up... All build plate was too heavy for 59Ncm Nema17's.
I could have left it with existing steppers, no one will ever print solid block or move it up when it's full - simply impossible but well... I still bought 65Ncm Nema17's. All good. That extra Ncm was the key!
Next was CoreXY and those tiny 45Ncm Nema's. It was ok, but with some pressure applied to XY it was skipping steps too easily for my liking so I simply replaced them with old Z 59Ncm Nema17's.
Success.
Next. Due to the weight of stainless steel rods in XY it was very "bouncy" when pushing it to 100mm/s+. So Went through the redesigning stages to make all the mounts much "beefier".
Forgot to mention - all my printers are based on SmartRapCore design (good old wooden box variant), quite redesigned iterations though but still SmartRapCore in it's heart. With this build I end up completely redesigning everything so probably going from the scratch is the best approach.
It was going strong, until I've attempted to print something bigger than testcube, Marvin and 3DBenchy...
I went with the train tracks for my little one, 350mm wide piece - ended up with "rollercoaster track" because it has warped so badly. PLA is good with warping but to some certain extent. There comes previously mentioned heated bed.
Hence bed is so massive and prints takes days to print in that volume - heating bed as one piece wasn't an option. Can't remember precise numbers but it was something close to 1.5/2kW - imagine running that for 48h+!!!
Then I was considering to buy 6x silicone heaters to cover all surface and power them up only where needed.
Bought only 2x to test (they aren't as cheap though, for 1x it's ok but for 6x... Yeah...)
Simple light switch stack was in mind to manually manage my grid. All grid (2x for now) was connected via SSR to Hotend (220v heaters heats up as quickly as hotend) and simple temperature controller I got off Amazon (like I had on my Jr for the heat bed).
It was looking good! Printed my train track successfully - I was pleased.
But then next problem... When I decided to print fairly high object. Heatbed was keeping print nice and warm up to 100mm of height and it was completely cold after 150mm... Yeah it didn't warped on the bottom but would start to delaminate between layers going higher.
So I've decided to go with something like heated chamber approach. Bought one of those mini ovens of Amazon and tried to disassemble it and then do all that heated chamber thing... That was a pain. Was trying to insulate everything, do pipes for hotend cooling. Reprint all the parts in PETG (was PLA)... Ahhh.... To be honest at that point I started to lose any interest in this project...
Slowly abandoned this project, then it was taking way too much space of my valuable small London studio space so I've disassembled it...
Later on I came to conclusion... PLA really isn't struggling of delamination isn't it?! So all that heat chamber thing was a bit of a waste of time... So yeah... One day I'll add it back to my to do list.

There were things I was considering.
1. 1x Nema 23 for Z instead of 2x Nema 17's. But decided not to due to the voltages. I do stick to 12v most of the time because I use ATX PSU's. And for most Nema 23 projects recommended power is 48v.
2. Not going with wooden box case. It's not the most rigid design, heavy as hell and is a bit flexible especially at sizes as 500x500x600. Oh and did I mentioned the noise??! Wooden box just resonates SO MUCH! But well - most of my machines at the time were wooden box design so yeah. Scrapped this idea. (Now I'm rebuilding my machines to alu extrusions so I would do alu this time.)
3. Instead of 8mm stainless steel rods go with Alu tubes and bushings to reduce weight. It was hard to get thick enough alu tubes at the time + I had boxfull with LM8UU linear bearings. And stainless steel rods were widely available so yeah.

Quite long but hopefully you'll find this useful.

38 (edited by Anthem 2016-11-11 14:38:17)

Re: Thoughts on extending the Da Vinci Jr

That is useful info, kr15_uk. Thanks. I'm already planning to use aluminum extrusion for the frame, and the design of my corner bearing blocks already has built-in stiffening plates (hence the weird shape and my suspicion they will be difficult to print), so hopefully rigidity won't be too much of an issue. If I have problems there I may add diagonal crossmembers or maybe turnbuckle tension wires.

The warping/heated bed is something that's been in the back of my mind. I've managed to print large-ish pieces on my not-so-jr with none, or minimal acceptable levels of warpage through adding brims and ears. This proposed build volume would take that to a new level, though. I'm trying to avoid heated beds because of the power consumption and weight, so it's of course going to be a challenge.

As for the steppers lifting Z, my build plate should always be empty when fighting gravity (homing), so the added weight of the plastic shouldn't be a factor there. I thought about using an Al plate as well, but your point about finding a flat enough piece is on point. It's hard enough to get flat acrylic. The steppers I have on hand are 45Ncm but I will likely buy new ones for this project, since these are probably going into my Dollo before then. Your experience with the 54s should be helpful there so I'll make sure to get hefty ones.

I've also thought about using gear reducers for the lift screws to help avoid those problems. I'm planning on 2 screws, and unfortunately the cheap option for screws is 2mm, where 1.25mm would give better mechanical advantage. The Z axis doesn't have to be fast like XY. It seems like a solvable problem, provided I can find a large enough, light enough plate material.

So thanks for the info. Definitely gives me more info and things to think about.

39

Re: Thoughts on extending the Da Vinci Jr

Quick question. Can I buy replacement linear bearings for the Junior y axis rods? Lm8uu for example.

40

Re: Thoughts on extending the Da Vinci Jr

gravy wrote:

Quick question. Can I buy replacement linear bearings for the Junior y axis rods? Lm8uu for example.

If it is made using bushings then your rods are not hardened and will not hold up to bearings. The balls inside the bearings are hardened and will score rods that are not hardened which is what XYZ uses since bushings won't score rods. So if you went to bearings you would also have to change your rods out to hardened rods as well.

Printing since 2009 and still love it!
Anycubic 4MAX best $225 ever invested.
Voxelabs Proxima SLA. 6 inch 2k Mono LCD.
Anycubic Predator, massive Delta machine. 450 x 370 print envelope.

41

Re: Thoughts on extending the Da Vinci Jr

Anthem wrote:

Y-axis extension, nearly complete! All I need is to get a new piece of glass for the top -- I'm actually thinking of going with acrylic, but I need to do some shopping.

Anyway, it's installed and working but using the stock 165mm glass plate for now. Here are some photos!

http://soliforum.com/i/?dPqeYs9.jpg
http://soliforum.com/i/?1ZADPnx.jpg
http://soliforum.com/i/?VCKvFaq.jpg

Leveling the bed is currently rather difficult, so I'm thinking of printing some new parts to make that easier (maybe using the new larger bed size to help me bootstrap this mod by printing longer brackets for the bed mounts including built-in leveling screws). However I managed to get it leveled enough that it still prints decently.

This axis assembly also is about 6mm higher than the stock axis, which is fine, but means you have to be extra careful about homing and moving axes (or at least being smart about setting your MIN and HOME_POS values in the firmware). The bed is now high enough that it can crash into the X axis if you're not careful.

I'm sure I'll be tweaking this for another week or two, so I'll keep you all posted, and I'll make sure to post photos when I have the new glass installed.

Anthem. Excellent mod you have there. Can you tell me exactly how you've mounted the bed to the slide rails and what are those parts either side of the print bed? Any links to the relevant stl files would be greatly appreciated.

42 (edited by Anthem 2017-02-23 23:25:38)

Re: Thoughts on extending the Da Vinci Jr

gravy, see here for the thingies on the side of the bed, which are the bed mounts: http://www.thingiverse.com/thing:1826941

The base of the bed is just an H-shaped frame of printed 2020 extrusion, joined with 90-degree vslot brackets, with three of these mounts attached to the outside of that frame.

Underneath,  I used four of these to mount LM8UUs onto the frame's crossmembers: http://www.thingiverse.com/thing:430288

And then for the belt, I mounted this underneath with a few printed washers to get the height right: http://www.thingiverse.com/thing:1827006

That belt clamp is actually attached to the underside of both crossmembers, so they're as far apart as the clamp is long.

The bed itself is just a slab of 5.6mm acrylic, and I attached it to the triangular bed mount "ears" using mounting tape.

For mounting the endstop, I printed a custom L bracket that the sensor screws into, and a simple flag that attaches to the outside of the H frame. I have models for those but they're not up on Thingiverse yet, but they're very simple to throw together.

The whole assembly as I have it is not perfect. In particular the 2020 slot frame for the bed carriage is finicky because it's hard to really get the screws and tnut really stiff at the joints, and I went through a couple revisions of the screw-down mounts before I settled on the current version with two nuts to lock it in.

I've been debating creating a new mounting bracket to replace the vslot bed frame, which can be all one piece and not quite as high (the current version reduces my Z by about 8mm), and also won't droop over time due to all the bolted joints.

Sorry for the lack of better pictures. If you need more info I can see about taking some more this weekend.

43

Re: Thoughts on extending the Da Vinci Jr

I can just simply say WOW.

Congratulations Anthem you've made a real good work there.

Regards!.

XYZ Junior/Mini Passwords Thread
If you are in a hurry and need your password NOW, or if it takes me too long for you, you can read the posts from 1851. I'm not going to be as effective as Bozo or Cgrillo, but you can give a try with me. If PASSWORDS thread follow it's current flow: asking for repeated passwords, not returning or false PACKS... I will end up with it as others before me.

44 (edited by Anthem 2017-02-27 03:31:52)

Re: Thoughts on extending the Da Vinci Jr

These are terrible photos (sorry) through the acrylic bed, but you can kind of see how the bed frame is put together.

http://soliforum.com/i/?XsJI5Gn.jpg

In this one you can see the top of the leveling "ear" that the bed is mounted to with mounting tape (It's just a thick and really sticky, rubbery kind of double-sided tape -- you should be able to find it at a hardware store). You can also see the basic construction of the bed carriage. It looks like an H with two crossmembers. The red pieces are four 90-degree brackets. This is where the drooping comes from -- they're mounted with only one screw per side into plastic T-nuts, so it loses its grip over time. I plan to replace this frame with something more solid eventually. You can see that the 2020 extrusion I used here was printed, and these black pieces are 150mm long.

If you look closely you can also see the (orange) LM8UU brackets underneath the crossmembers. There are four of these (in theory you can get away with three and reduce any binding, but considering the length of the bed [425mm] I thought it was worth the risk of potential binding to have the extra stability -- plus I only have two crossmembers here, and a three-bearing setup should have the third halfway in between the other two). In the original photos you can see the printed 8mm rail holders I'm using -- it's actually easy enough to incrementally self-orient these in parallel by tightening down only one pair of bearings, keeping everything else loose, and sliding the bed back and forth, gradually tightening all the other parts until you end up with a parallel setup.

http://soliforum.com/i/?Z8EaXNL.jpg

In this second photo you can (barely) see the black belt clamp underneath the bed frame. It's mounted "upside-down" and to both the crossmembers. There's a little bit of tweaking to do here, because I figured out the hard way that there are screws that stick up from the bottom of the printer's chassis that can get in the way here. The tolerances aren't too tight but I had to do some adjusting to make sure the clamp didn't collide with them.

45

Re: Thoughts on extending the Da Vinci Jr

So this is cool -- I'm making progress with upgrading to four extruders smile


I've had two additional extruders printed and assembled for some months now, and I've had the extra stepper drivers on hand, but naturally as RAMPS 1.4 only provides two extruder driver slots, I haven't been able to hook them up.

I had figured out the pinouts on the drivers and had a breadboard implementation kind of working, but let's be honest -- I didn't have the time or motivation to "do it right" and solder my own board to match the schematics for that, and I wasn't about to hook up the breadboard implementation to my RAMPS board (I've learned my lesson about leaving things "loose" like that too many times).

So I bit the bullet and bought a couple of these beauties: http://www.reprap.me/stepper-expander-x2.html

I hooked one up to my Not-So-Jr and have two more steppers controllable as extruders now. This weekend I plan to screw everything together and mount the new extruders.

I'm going to be setting this up in a 2x2 sort of configuration, with two extruders each leading to two Y-splitters on each of two hotends. I'll need some custom gcode to control that, but it's a problem that's been solved before.

Now, one thing I had to solve, is that Marlin does not have support for "sharing" hotends between multiple extruders. It's easy enough to set the TEMP pins the same and see the right temps associated with each extruder, but I found that setting the temps is tricky -- to actually get a hotend to heat, because Marlin thinks each of the four extruders to has a unique heater, you have to set the same temperature on BOTH extruders at the same time, otherwise the PID heating algorithm just keeps setting and unsetting the heating pin and basically nothing happens.

So I had to fix that -- and fix it I did. I just found the "setTargetHotend" function and added some new settings so that any time the temperature gets set for EITHER of the extruders with a shared hotend, it actually sets them both simultaneously. Not too hard.

This actually seems to be working. I've done a few single-extrusion prints since setting that up and things are working fine. The only thing standing in my way now (besides me) is the fact that I'm running low on bowden fittings (I've had to replace two or three in the last couple months), and I need to re-print the Y-splitters I'll be using, since one of the first designs I tried didn't work so well.

Be sure I'll keep you posted. Hopefully pretty soon my hacked-up Da Vinci Jr will have two-bit color smile

46 (edited by Anthem 2017-03-05 03:58:26)

Re: Thoughts on extending the Da Vinci Jr

I don't have four colors quite yet... But I do have three!
http://soliforum.com/i/?NxNDPg0.jpg

Lessons learned:

  • This Y-splitter works fine: https://www.thingiverse.com/thing:1680034 however, it can be finicky and you have to do some cleaning up of the print. I used a round 150-grit needle file to clean out the inside of it to make sure the filament wouldn't catch going through. This was actually my third time printing these devices, not being happy with my first two results. This last best print came out of my new MP Select Mini using Inland White PLA (of which either I got a bad batch, or it just always really sucks -- it has terrible layer adhesion and 210c is a minimum for a print that doesn't just fall apart)

  • PC4-M5 fittings can also be really finicky. The last batch I ordered had a really sharp ridge on the inside of the M5 threaded end. I again had to use a round needle file to smooth down these edges on all the PC4-M5 fittings I used for the Y-adapter to make sure the filament didn't catch during retraction/reinsertion.

  • I also had to drill out the M5 end of the "exit" fitting (hotend side) because the hole was smaller than the one in the Y-adapter, so the filament was getting caught on that edge too.

  • Related to the above, when screwing in the PC4-M5 fittings (which self-tap just fine into the adapter), resist any temptation to NOT screw it in all the way (for fear of breaking the print). Kind of like the hotend barrel, if you leave any gap between the fitting and the Y-adapter, the filament will find a way to get stuck in that gap.

  • Don't forget to add a prime tower (I forgot to in the print above -- you might notice some green/white blending if you look really close)

The gcode I used is actually pretty simple. My start gcode assumes that the filament has already been retracted into the Y-adapter (the full retraction distance I use is 110mm), so it starts by heating, then slowly re-inserting 110mm of filament.

The toolchange gcode then quickly retracts 10mm (to start the filament cooling), moves the X carriage back to 0 (to get it off the print), and then quickly retracts the remaining 100mm to clear the Y-adapter. It then switches temps (I cool the inactive hotend to 160), switches tools, and slowly reinserts 110mm of the new color.

I'll try to get my Marlin patches and all that posted up soon. I did find out that setting the per-nozzle temperature via the LCD isn't fixed by my patch the way temp settings via gcode are fixed, so I might either find a way to fix that, or I might live with it for now (the workaround is to set the OTHER nozzle's temp to the same value before Marlin times out with a "heating error" -- certainly possible to do if you remember to do it).

I've ordered more PC4-M5 fittings... I ran out smile But once I get them I'll be setting up my fourth extruder and the Y-adapter for four glorious colors.

Next extruder upgrade... mixing hotend (maybe a diamond?) with Y-splitters for full six-extruder CMYKWT color? smile

47

Re: Thoughts on extending the Da Vinci Jr

Oh, and one more lesson learned -- Right now I have logical extruders 0 and 2 mapped to the left nozzle, and extruders 1 and 3 mapped to the right nozzle.

It appears to be better to share a nozzle with consecutive extruders, so that left = (0, 1) and right = (2, 3). This is because slicing software typically prints with each extruder in numerical order, so if you interleave the numbers like I have, then *every* tool change requires a nozzle reheat. If you map them consecutively, however, then you halve the number of reheats needed.

Should be a simple change -- with RAMPS I can just move the stepper cables to switch extruders and then update the extruder/nozzle mappings I put into Marlin.

48 (edited by Anthem 2017-03-11 06:27:14)

Re: Thoughts on extending the Da Vinci Jr

OK guys, here's my best print yet with four colors. Granted it's still just a calibration piece, but it's proof that it's working (and rather decently at that).

http://soliforum.com/i/?XA6TXzR.jpg

This has been a fun but frustrating ride. I've had the hardware set up for several days now, but getting Simplify3D to work well with four colors has been tricky. It likes to make a lot of assumptions.

This is before "cleanup" with the 3-layer/4-color ooze shield still in place, and it highlights some of the problems and solutions to them I've been solving:http://soliforum.com/i/?xiFvxE7.jpg

(And yes, it looks like I need to tighten up some belts)

Surprisingly, I haven't had too many issues with the filament not reloading into the adapters properly. I gave everything a good reaming with drills and files to eliminate some of the early issues, but I haven't hit any major issues with stuck filament lately.

Most of the problems have been software related. First off, while S3D is pretty powerful and useful for a lot of things (and I like the surface finish I get with it), configuring it is really, really hard. I hate its configuration model. Give me Slic3r-like settings any day.

Anyhow, getting the retraction settings coordinated is the first major hurdle, and it wasn't too bad, but S3D likes to issue a toolchange on the first tool. That means my start gcode has to reload filament, only to have it retracted and reloaded again before anything even starts printing. Weird and annoying, but not a big deal.

Getting a clean print is tougher. With dual extruders, I already was decreasing the temp of the inactive extruder in my toolchange decode (S3D doesn't have built-in support for that, even though with a $150 price tag it seems like it should -- even Slic3r can do it with a prefab setting). That helps a lot. And with the filament retracted 100mm above the adapter, that means it's virtually impossible to get leakage from your inactive extruder.

The bigger problems have to do with purging colors using the same nozzle. S3D, again, fails it here. While they offer prime towers, the prime tower only appears to work with two colors, and there can only ever be ONE prime tower. Seems like for best results there should be one tower per nozzle, but there's apparently no way to achieve that, and S3D assumes I want the prime tower to use the first two colors (which for my setup are on the same nozzle, meaning the other nozzle never gets primed). So, S3D prime towers are stupid and useless with my setup.

I tried using a "purge bucket" technique, by moving the hotend away from the bed, then purging ~30mm filament after changing tools. That produces great colors, but there's a fatal flaw in my setup, where one of my nozzles is always over the bed. Purging over the bed is bad.

So, I tried a technique where the nozzle to be purged gets moved off the bed first. That means purging the left nozzle moves the carriage all the way left, and vice versa. This works... mostly. Problem is, because I have to change the active tool in order to purge the right nozzle, Marlin applies the tool offset as well. So as soon as the G1 command to extrude gets processed, it extrudes while slowly moving the carriage back over the bed. That turns into a big mess at the end of the bed that ends up dragging goop all over the print.

I'd really love to go with a purge bucket technique, since that eliminates the need for any other sort of priming and produces really clean colors, but unless I can get this offset problem figured out (where somehow I can purge T2/T3's filament without applying T2/T3's X offset), it's off the table.

So, my interim solution is to use an excessive ooze shield. This, at least, S3D does well. You can make the ooze shield print with all of the colors after a tool change, and you can set the offset and number of walls. So I create a very heavy ooze shield (in the piece shown, each loop is about 10cm in length. At 0.1 layer height, 0.4 extrusion width, each 100mm of extrusion counts for about 4mm of filament length, so three loops purges about 3cm of filament.

With that setup, I'm still getting some unclean color in the red (tool 4) after printing black (tool 3), making the red muddy and dark, but I'm thinking this has to do with my filament temperatures. This red prints at 210, while the black prints at 190. I'm thinking what's left of the black that's still in the nozzle when the red primes is basically liquifying at that temperature and mixing with the red. A longer purge of the red would probably help there, but without the purge bucket idea working, that's hard to achieve cleanly. You can see more evidence of this in the "pre-cleanup" shot where there's also a big black streak where the filament started to purge (or leak) on the reload.

Anyhow, here are some more photos. This one's of the adapters attached to my two E3D Lite6s:
http://soliforum.com/i/?zgdVvJF.jpg

And a shot of my four extruders:
http://soliforum.com/i/?XlqDyVb.jpg

They're all different colors for easy identification. In tool order, it goes red, blue (it's in the background attached to the other side of the frame), black, then white.

All my settings at the moment are S3D specific. I configure four extruders with normal settings, then I set up two temperature controllers, one for the left nozzle, one for the right. I then define a new process for each color I'm using, and in that process configure the temperature controllers appropriately for the active/inactive tool temperatures I want. Unfortunately, though, S3D only uses the temperature controllers between layers. I need temperatures to change for the same nozzle within the same layer. So that part is handled with my toolchange gcode.

The Start, Toolchange and End gcodes work together to manage the retraction. When off, all filament needs to be retracted above the adapters. The start gcode reloads the filament (100mm in my case) up to the nozzle after heating, and uses G92 to make sure the other tool E positions are set correctly. S3D issues a G92 E0 right at the beginning of the print, after the start gcode, so this only applies to T0 which has been loaded to the nozzle.

The toolchange script moves the X carriage all the way left (so that if there's any leakage during retraction or heating, it doesn't hit the print) and retracts the filament to -100 before switching tools (this happens after any layer change or normal retraction is done - I use 6mm for my bowden setup). I set S3D's own toolchange retraction setting to 0 so that I can override its behavior without surprises in my gcode (otherwise, it would force me to use the same retraction and reload feed rates, which I want to customize -- retraction can be much faster than the reload, which needs to be slower toward the end in case of accidental purge). After fully retracting, it readjusts temperatures, switches tools, and reloads the filament before continuing the print.

This setup requires an ooze shield, not just to avoid leaks from the nozzle when moving X back into place, but also to  prime the colors as I explained above.

In the photos above you can see a few artifacts of the X carriage "idle" position while reloading and reheating -- there's a couple of streaks where there was some accidental purge and the ooze shield didn't catch it all. I'm still playing with retraction settings to see if I can avoid this (another "normal" length retraction just before moving X back over the print might help).

Start gcode:

M42 P58 S255 ; turn on the lights
M104 T0 S[extruder0_temperature]
M104 T2 S[extruder2_temperature]
G28
M109 T0 S[extruder0_temperature]
M109 T2 S[extruder2_temperature]

T0 ; reset tool to T0
G92 E0
G1 E110 F1000 ; reload T0 filament at a medium pace

; record other filaments as retracted
T1
G92 E-110 
T2
G92 E-110 
T3
G92 E-110 
T0

Toolchange gcode:

; toolchange script runs post-retraction old_tool's E is <= 0 right now
; don't use S3D's toolchange retraction with this or distances will get messed up

; move new hotend out of the way for cleaning purge
T0 ; move relative to T0
G1 X-32 F6000; move X left for reload

; if we want to purge
 do this...
;{IF NEWTOOL=0} G1 X-32 F6000; move X left for T0 purge
;{IF NEWTOOL=1} G1 X-32 F6000; move X left for T1 purge
;{IF NEWTOOL=2} G1 X155 F6000; move X right for T2 purge
;{IF NEWTOOL=3} G1 X155 F6000; move X right for T3 purge

T[old_tool] ; switch back to old/current tool for retraction past splitter
G1 E-100 F6000

; change temperatures
{IF NEWTOOL=0}M104 S[extruder2_temperature] T2 ; set T2 inactive extruder to cooldown temp
{IF NEWTOOL=0}M109 S[extruder0_temperature] T0; Set T0 new active extruder to normal temp and wait for it to reach temperature before proceeding.
{IF NEWTOOL=1}M104 S[extruder2_temperature] T2 ; set T2 inactive extruder to cooldown temp
{IF NEWTOOL=1}M109 S[extruder0_temperature] T0; Set T0 new active extruder to normal temp and wait for it to reach temperature before proceeding.
{IF NEWTOOL=2}M104 S[extruder0_temperature] T0 ; set T0 inactive extruder to cooldown temp
{IF NEWTOOL=2}M109 S[extruder2_temperature] T2; Set T2 new active extruder to normal temp and wait for it to reach temperature before proceeding.
{IF NEWTOOL=3}M104 S[extruder0_temperature] T0 ; set T0 inactive extruder to cooldown temp
{IF NEWTOOL=3}M109 S[extruder2_temperature] T2; Set T2 new active extruder to normal temp and wait for it to reach temperature before proceeding.

; switch to new tool and issue our own restart gcode. S3D's restart length if set will extrude beyond this point

T[new_tool]
G1 E-30 F6000 ; restart (fast most of the way)
G1 E0 F300 ; restart slow last 30mm

; skip purge for now
; G1 E25 F100 ; purge 25mm
; G92 E0 ; reset position to ignore purge length

End gcode:

; end gcode
; E is at <=0 (retracted) at this point

G28 X ; home X to get it out of the way
G1 E-100 F600 ; retract filament into Y-splitter
T0 ; Switch back to T0

M104 S0 T0; turn off extruder 1
M104 S0 T2; turn off extruder 2
M140 S0 ; turn off bed
M106 S0 ; turn off cooling fan

G90 ; absolute positioning

; G1 Y400 F5000 ; present part

M84     ; disable motors
M42 P58 S0 ; turn off the lights

This weekend I might try translating my settings into Slic3r to see how that goes. I worry about priming, though, because Slic3r's ooze shield is only a single color, and it has no prime towers to speak of (though there's a new post-processing prime tower script I found on reprap.org that I'm eager to try out).

I also haven't tried printing TPU in this setup yet. I was able to print TPU at <30mmps with these extruders previously, despite being a bowden configuration, but I'm wondering if the extra long retractions and the physical features of the Y-adapter construction might make that much more difficult. I'll definitely post here once I've tried it.

49 (edited by Anthem 2017-03-12 17:18:34)

Re: Thoughts on extending the Da Vinci Jr

<farnsworth>Good news, everyone!</farnsworth>

I tried printing with TPU this morning, and everything seems to be working fine (at 25mm/s at least), which I think is pretty impressive. That means I haven't lost any obvious functionality by adding in the y-splitters.

Also, since I've been printing in a lot of exotic filaments lately, I decided to invest in some Micro-Swiss hardened nozzles, and I got those installed and my bed re-leveled as well (the new nozzles are about 0.2mm longer than the stock E3D brass nozzles).

And, finally, I completed another "test" print with four colors. This one was a slightly simpler road cone, where it only changed colors on layers. Unfortunately I broke it between the black and green layers while trying to remove it from the bed (slipped while trying to remove the ooze shield), but it otherwise turned out quite well! I'm still having an issue with the black bleeding into the red on the same nozzle for some reason, but I still suspect it has to do with the characteristics of the black filament at that temperature. I'll be trying some different filaments soon to see if they behave a bit better.

http://soliforum.com/i/?HfPK3Mc.jpg

Also, I think I've figured out how to solve my tool offset/purge on the right nozzle problem. Gcode M218 can programmatically reset the hotend offsets, and I found that if I reset my T2/T3 offsets to 0 before switching tools and performing the extrusion G1, I can get it to not move the X axis. After the purge, I can reset the tool and reset the T2/T3 offset back to the correct settings.

Unfortunately this means a little more complication in the gcode, and I have to duplicate my hotend offset values in my toolchange gcode (I usually prefer to have these measured values set only in firmware), but I think it's workable. Now I just need to design a catch or slide for the purged filament, and I'm thinking I'll create a thin TPU "blade" that can wipe the hotend as it returns to the bed, as well. That should eliminate the need for prime towers or excessive ooze shields entirely. Maybe, if I perform a standard retraction after the purge, I also can mostly eliminate the need for an ooze shield as well.

50

Re: Thoughts on extending the Da Vinci Jr

Anthem IMHO you deserve the mod of the year award for this .

I am not a davinci fan although I was tempted to by one as a first printer.
I did however get bit by the build bug and did a kit build and just ordered a second kit build. I know in the beginning I thought you crazy  for doing this extreme mod.
What can I say it works . you did things others including myself would have not attempted. Congratulations are in order and I hope this thread has led others to follow their dreams.
Tin

Soliddoodle 4 stock w glass bed------Folger Tech Prusa 2020 upgraded to and titan /aero extruder mirror bed
FT5 with titan/ E3D Aero------MP mini select w glass bed
MP Utimate maker pro-W bondtech extruder
Marlin/Repetier Host/ Slic3r and Cura