A different multi-extrusion approach - UM tool / printhead changer

[foehnsturm 969]

Just printed a bracelet with Faberdashery and Recreus Filaflex. I suppose I won't do that again. Filaflex is almost impossible to handle with dual. When idle the hotend more or less empties by itself.

Edited May 2, 2015 by Guest

[neotko 1,417]

I'm stuck on the head changer. The magnets have enough force to hold the head, and I can print ok (I just finished installing everything 4h ago). I think my 'small' design can't be this small. I need to put more magnets, to have a better 'catch' of the head and I need to change fully the dock station because the side sliders of umo and maintly because the tension of the bowden. If I place the parks on the end of the machine the bowden pushthem, so I changed the orientation to put in on the front and it holds better but my hangar has many flaws now that I see it with the head.

I need to make a helper like the one foehnsturm did to push the head on the hangar and propably I will have to redesign some stuff to use a stronger magnet.

At least I can print with the mod (one head for now).

EDIT: Lol it works, I was using one of the 3 bad versions of the hangar... My desk it's a mess of prototypes. Well I still need to change the hangar, but not the lower part, just the upper area so the left-right sliders go in just a bit. The magnet now that I'm using the correct bay works fine, but not superb. Good think it's that when using one head the printing area it's 197x196mm, so if you take one head outside you can use almost the same area. With 2 heads I think it will be like 175x175 or something alike.

Edited May 2, 2015 by Guest

[ultiarjan 1,223]

Maybe just use slightly stronger magnets? it started with 2mm ones and changed to 4 mm thick , made all the difference ...

I was hoping to do my first dual extrusion print this weekend but still did not receive the UM parts...., at least I got a tracking number now so the stuff is on its way.... but now I'm traveling all week :( so it will have to wait till next weekend.

[ultiarjan 1,223]

and @Neotko, if you can share a video of the changing ... curious to see it in action ..

[neotko 1,417]

Well at least finally they send the items, can't wait to see your version.

I can't really show a video of the changing. I just did the basic change 'by hand' moving the heads. I just finished a new hangar I'll check the small head printing something more than just a small flat area, will be a nice test also to see if works at 50-80mm/s or if the head flys XD (I hope it doesn't...)

One good think (I' think) it's that the UMO+ has the second extruder on the oposite direction, so the bowden 'push' should be fine for each extruder.

[neotko 1,417]

Single head printing. So far the head holds just fine. Printing new hangar/bay hopefully this one will work and I'll be able to show a video of the head changing.

 

So nothing exciting to see just yet.

[neotko 1,417]

Well the hangar/bay design it's much better now.

 

Just manual docking. The movement it's clumsy because I was moving the heads with just one hand to hold the phone.

Also while finishing assembling the second head now I have a 0.7 height difference. I think it's the peek (one it's new and the other it's heavy used).

I think I'll search m4 size aluminium springs and add them between the wood that holds the ptfe isolator so with the upper screws it can be 'recalibrated' to solve both head heights. Now I need to find the springs.. Umm maybe with the spring of a pen and cutting it in 3 parts. Other solution it's to manually file the wood that holds the isolator but don't seems like a hood idea on the long run.

I have changed the docking bay to have a little curved space so the cables don't push the head.

Foehnsturm how do you adjust both heads? Are they exactly the same or you have any alignment mechanism?

[foehnsturm 969]

I'm using Merlin hotends which are screwed into an aluminum mounting piece. So I can rotate the hotend a little to adjust height. However that sounds better than it actually is because the nozzle tip is not perfectly in line with the rotation axis. So adjusting height has to be follwed by adjusting x/y offset.

[neotko 1,417]

I see. I will try the springs idea this week. Other idea I had this morning was that using a caliper and add a z+ or z- when the head changes? The problem it's that one could hit the bed but since they are on the bay it shouldn't be much throuble. If I get free time this week I'll give it a go but I still need to solder x2 fans for the second head. Also my fan design it's suffering from pla meltdown (they hold for now) but I need to move them a bit away, or maybe I'll just ditch them and finishing my crossflow fan setup.

The good stuff it's that the head design it's totally modular and easy to replace the parts. Adding springs or removing fans it's just a minutes operation. And it's printing nicely. So now I need to focus on the gcode, drilling a new hole for the y endstop and getting the spring idea working.

[neotko 1,417]

Well. Basic head alignment does work. Got a pen and took the spring and cut it in half.

Atm I'm printing with the lowest height to check if affects or fails and so far everything works. Next step assemble the hangars and get my hands on the gcode.

[neotko 1,417]

Arhh can't edit on mobile. Ok this it's the video of the head aligment with the spring

 

[neotko 1,417]

Well tiny update.

So far the 'springs' on the head where on a bad positioning that caused a leak because the white teflon isolator changed the angle.

The solution (I should have think of this first) was easy, just by moving the springs directly on the upper part of the wood, so the isolator it's always being pushed onto the peek). Like this:

Also used a third spring on the back screw to help with stability. The head it's printing like a charm, after 12h prints no leaks and perfect prints.

I'm also finishing a better hangar, so it can be removed and used as one need's it. Without any american tape or similar, and if you want to secure it you can use the lateral holes of the end stop to combine it with the endstop. Anyway it's a semihard fit, and it's really easy to remove.

Also finished soldering the 4 fans for the two heads and did a full clean up on how the cables go through. I hope to be able to run some two head tests this weekend, but I need to learn how to script the head change on Simplify3d or do it manually. Any head changes I do by the ulticontroller work and work really nice.

I'll try to post the stls next week as soon I don't find any other critical bug on the design.

Anyone have experience scripting the tool change on Simplify3d?

[ultiarjan 1,223]

I tested the changing using the "layer" script in Simplify3D, I'll try the tool change tomorrow...

[ultiarjan 1,223]

I got all the ordered parts, and just mounted the head, not jet connected to the board, to tired now, spend a big part of today in massif traffic jams in Germany :(

Did already try the fans with external power, will set it up with external power to get started.

I just figured I probably need to activate the 2th extruder/heater/tempsensor in firmware and that I have no idea how to do it ....

Do I only need to change stuff in "Configuration.h" ?

When I see this >

 

// This defines the number of extruders#ifndef EXTRUDERS#define EXTRUDERS 1#endif

 

I think I need to change it to> #define EXTRUDERS 2   (correct?)

Looking at the sensors... which one is 0/1/2 ?  why is sensor 2 set to 0 ???

 

#define TEMP_SENSOR_0 20#define TEMP_SENSOR_1 20#define TEMP_SENSOR_2 0#define TEMP_SENSOR_BED 20

 

Heaters are set ok by  deafault ? like this ?

 

#define HEATER_0_MINTEMP 5#define HEATER_1_MINTEMP 5#define HEATER_2_MINTEMP 5#define BED_MINTEMP 5

 

Do I need to make changes in other places  of the firmware ?

Edited May 9, 2015 by Guest

[neotko 1,417]

Yeah put temp sensor 20 if you use pt100. 0 it's for disabled.

With that changes you should be ok.

I found how to s3d tool change script. It's quite easy. I will write the correct stuff this sunday (I hope) but it's something like:

EDIT. Deleted code that was wrong

I didn't have more time to test since I'm having a problem with one of the extruders... But that script will give you the idea I think.

Edit: Ok just 5 mins in front of this and now I get it. It's really really easy

(Don't use this numbers ofc it's just for the preview and etc etc) But it does work, check the preview on S3D

{IF NEWTOOL=0}G0 F15000 X100 Y100

{IF NEWTOOL=0}G0 F7000 X0 Y100

{IF NEWTOOL=0}G0 F15000 X0 Y0

{IF NEWTOOL=0}G0 F7000 X100 Y0

;

{IF NEWTOOL=2}G0 F15000 X190 Y100

{IF NEWTOOL=2}G0 F7000 X190 Y0

{IF NEWTOOL=2}G0 F15000 X100 Y0

{IF NEWTOOL=2}G0 F7000 X100 Y30

Now I just need to do the full movement instructions, and should work.

Edited May 9, 2015 by Guest

[ultiarjan 1,223]

small update;

Build everything together, successfully printed with the 2th head (single extrusion) by setting this extruder in Simplify3D.

Leveled the nozels and now want to start the calibration of the X offset, but now I'm stuck, can't get dual extrusion going on. Made a calibration object in Cura, but I does not work.

Please have a look a this question ...

Edited May 11, 2015 by SandervG

[ultiarjan 1,223]

And here's the video (again tooo longgg) of my very first ever

dual extrusion print... obviously a calibration print...

I decided to go with Simplify3D, took me a while to master all

settings, but I think I finally understand at least some of it...

the dual extrusion setting are somewhat difficult spread out over

all the settings tabs .. but the abillity to add custom code for

every tool change is super.

The hotend fan of the 2th extruder is on a fixed 5 volt supply,

the side fans are on a manually regulated powersupply

 

So the next stuff will probably be

- correct XY offsets

- print cooler and faster (video is 205c)

- try 0.15 layers i.s.o. 0.3

- ditch the colorfabb, too much oozing, the faberdashery grey

works better, try other brands.

- add temperature control to toolchange code

- Improve the startup code, prevent the "dipping in plastic"

- find out why the 2th nozzle didn't prime / add manual

and play around more and more ...

Edited May 11, 2015 by SandervG
Fixed YouTube video

[ultiarjan 1,223]

FYI,

Here's the change code for Simplify3D

Always start with Head 0 mounted ..

 

;*;***************************************{IF NEWTOOL=0};change to Tool Zero-Left{IF NEWTOOL=1};change to Tool One-Right;***************************************G10{IF NEWTOOL=1}G0 F9000 X8.6 Y160 ; back to start T-zero - left{IF NEWTOOL=1}G0 F9000 X8.6 Y49 ; move front park T-zero - left{IF NEWTOOL=1}G0 F9000 X182.2 Y49 ; move to right,pick T-one{IF NEWTOOL=1}G0 F9000 X182.2 Y160 ;move T-one to the back - right;{IF NEWTOOL=0}G0 F9000 X182.2 Y160 ;move T-one to the back - right{IF NEWTOOL=0}G0 F9000 X182.2 Y49 ; move to right,park T-one{IF NEWTOOL=0}G0 F9000 X8.6 Y49 ; move front pick T-zero - left{IF NEWTOOL=0}G0 F9000 X8.6 Y160 ; back to start T-zero - leftG11;***************************************;*

 

[ultiarjan 1,223]

I guess I'm spoiled with my UM2, I keep forgetting the manual stuff. Forget to remove the first change from gCode and you get a crash

The tinkering and testing is addictive... for the first time since ages I'm having some under extrusion issues.

2th calibration thing, a lot better than the first;

Underextruded Ultibot, think the issue is that besides dual extrusion I'm also learning how to use Simplify3D... but I'm very satisfied with the result on the first day.

It's clear there's a lot of difference in material. The white is  faberdashery 'architect stone' very nice! the other is faberdashery earl grey, stringing a lot worse..

Will need to set the retraction during head change manually, to separate from the normal retraction, and need to try some different kinds of nozzles.

Edited May 10, 2015 by Guest

[neotko 1,417]

I'm sure that this isn't your problem but on my mod I had understrusion for a long irritating day and in the end was that the bowden clamp replica (3d printed) was 0.12mm bigger than the molded plastic. I had to use a low speed rotating device to clean evenly (that's what I get for using cheap pla) and now it's extruding perfectly. I think that the clamp was doing more force than the necessary to hold the bowden and that added extra tension to the feeder.

[Labern 774]

That's looking great @ultiarjan

[foehnsturm 969]

Congrats! Great to see the machanism handling the stock hotend assembly as well.

There is one idea I'd like to discuss.

To me it looks like there's an easy way to use different nozzle sizes and slicing settings (infill etc. NOT layer height) per extruder. Just run the slicer two times on the entire part with different settings and replace [extruder2] sections in file1 by [extruder2] sections in file2. With the same layer height and the printer running in relative E mode everthing should be fine. Am I missing something?

[ultiarjan 1,223]

@neotko I think my underextrusion issue in the latest print is caused by the nozzle dripping during pauze, think I'll test a priming tower to solve this, later this week.

@foehnsturm different nozzle sizes should be easy as it's already supported by Simplify3D, it's just an easy setting to f.e. use a 0.6 nozzle for infill. I decided to wait for Pink Unicorn before putting effort in dual extrusion with CURA.

I do expect (will for sure try later) more fillament dripping during pauze with the larger nozzle...

Plan is to first improve with the current nozzles and various materials (o.4 E3D) and later try the others, I have f.e. also the "3D solex jet" nozzles to test with (think even 2 types). Does anybody know how the UMO nozzles compare to E3D with regard to dripping ?

[neotko 1,417]

On my UMO+ 1.75mm E3D drips much less than ultimaker-kind nozzles.

You could try to increase the tool change retraction on S3D (I think it's on advanced) and maybe add an extra extrusion for the pickup to compensate the filament lost on the drip. Ofc a priming tower should work. Also, since there frontal area it's almost lost when dual, you could add the priming tower there as a standard. You could pre-render the gcode and copy-paste the tower and make it render it every time after picking the block.

Edited May 11, 2015 by Guest

[foehnsturm 969]

So far I tried ooze shield, priming tower, extra retraction and prime on change, lowering temp, ...

To make it short:

Ooze shield / priming tower help to dial in extruder flow before printing the actual part and to deposit eventual filament blobs somewhere else.

Some filaments are quite easy to control (e.g. faberdasherey white) some ooze like hell (e.g. Recreus filaflex).

If one extruder pauses for more than a few layers, none of the above mentioned methods will really solve the underextrusion issue due to dripping.

But the benefit of this approach is having the idling extruders parked in a separate place and perform a special movement pattern to get there. One could take advantage of that.

The most successful attempt so far for prints with long idling times: I extrude quite a large amount before picking up the extruder (depends on filament, up to 10 mm with filaflex / remember I'm using direct drive!) and use a small spring steel blade (attached to the holder) to wipe off the excessive filament when the printhead moves out of the holder.

AFAIK this is like some working dual solutions handle it as well: move somewhere outside the printing area, do excessive priming, clean the nozzle, return.