DXU - Efficient Dual Extrusion Upgrade for UM2+

[yyh1002 60]

16 hours ago, garaha2012 said:

Hi, everyone,

congratulation for the great work yyh1002, very impressive!

l do have a question:

The hot end unit that moves up and down surely has some play in it otherwise it would not move up and down.

When the hot end is in the down position how is the unit held in its precise x-y-location?
On my UM3 the precision comes from the spring pressing the moving hot end unit down against a tapered seat in a metal part at the bottom of the head.
Which part or which lay-out in your design ensures the x-y-position precisely?

Or do I expect problems where there is none??

Thanks and sorry to ask this after everyone says it prints fine.

 

Thanks. Good observation. On the front housing, there are two bores to restrain the hotend for xy precision, one is above the heatsink and spring, the other is around the bowden coupler. Both bores have teeth around them so it's easier for the hotend to slide. I made the tolerance quite tight and use a drill to spin the hotend inside the housing to run-in. It's metal vs plastic so they fit quite well without being all fixed.

 

I agree that it's not as precise as UM3's tapered socket solution, technically. But I think it's good enough for 3D printing purpose if fitted well, just like the brass bushing on XY rails. I would like to go with more precise solution if I have easy access to machines. 

 

9 hours ago, luke199 said:

Hey guys,

 

just to confirm the PI insulator goes between the nozzle and boden tube? has anyone had any problems with leaks or disassembly where the boden meets the insulator?

 

The PI insulator does go between the nozzle and bowden tube. The bowden tube coming with hotend is intended to be used without PI insulator, so it needs to be trimmed slightly shorter. But the total length of tube+PI should be slightly longer (about 0.5mm) than the shaft to keep the bowden tube in compression so it doesn't get squeezed shorter by hot filament over time.

 

You need to make sure the nozzle is right up against the heat break, metal to metal. Heat the block to at least 160 degrees before install. And hold the block firmly when screw nozzle in. If there is cold plastic, debris or air gap between the nozzle and heat break, it will leak. 

[luke199 0]

On 10/10/2019 at 3:03 AM, yyh1002 said:

 

Thanks. Good observation. On the front housing, there are two bores to restrain the hotend for xy precision, one is above the heatsink and spring, the other is around the bowden coupler. Both bores have teeth around them so it's easier for the hotend to slide. I made the tolerance quite tight and use a drill to spin the hotend inside the housing to run-in. It's metal vs plastic so they fit quite well without being all fixed.

 

I agree that it's not as precise as UM3's tapered socket solution, technically. But I think it's good enough for 3D printing purpose if fitted well, just like the brass bushing on XY rails. I would like to go with more precise solution if I have easy access to machines. 

 

 

The PI insulator does go between the nozzle and bowden tube. The bowden tube coming with hotend is intended to be used without PI insulator, so it needs to be trimmed slightly shorter. But the total length of tube+PI should be slightly longer (about 0.5mm) than the shaft to keep the bowden tube in compression so it doesn't get squeezed shorter by hot filament over time.

 

You need to make sure the nozzle is right up against the heat break, metal to metal. Heat the block to at least 160 degrees before install. And hold the block firmly when screw nozzle in. If there is cold plastic, debris or air gap between the nozzle and heat break, it will leak. 

 

Thank you, just to make sure it's clear.  I do the follow.

 

1 place the PI insulator into the heatsink and screw tight into the heater block

2 screw nozzle in afterwords.

 

and this would mean the nozzle will stick out the heater block a little more.

 

 

[yyh1002 60]

2 hours ago, luke199 said:

place the PI insulator into the heatsink and screw tight into the heater block

Not really. There needs to be about 1-2mm spacing between the top of heat block and hex flange on heat break. The block is loose before install the nozzle, and you can turn it to proper direction so it doesn't touch anything. When nozzle comes in, it will lock everything tight. 

[Garufa 11]

There is a printer definition in the latest Cura for Mark2 variant, has anyone edited to create a DXU profile in Cura 4.3?

[luke199 0]

Hey all,

 

What's the recommended general retraction length and maximum?

[Garufa 11]

The DXU works with Cura 4.03 if choosing the Mark2, input your printer specific dimensions and filament, even the post processing file works, change the start- Goode to match the DXU profile we have in Cura 3.6 and that’s it..so far I have printed calibration cubes with dual color with no issues, have not printed a large model yet.  Think it is promising 

[Garufa 11]

DXU and Cura 4.3 - changed the disallowed areas to match the DXU def.json file and the backplate image. Print area is now showing as the original DXU - without it the print area is minimal on the Mark2 def.json if choosing extruder 1 and 2

does anybody knows if other changes are needed?

[yyh1002 60]

1 hour ago, Garufa said:

DXU and Cura 4.3 - changed the disallowed areas to match the DXU def.json file and the backplate image. Print area is now showing as the original DXU - without it the print area is minimal on the Mark2 def.json if choosing extruder 1 and 2

does anybody knows if other changes are needed?

I haven't checked the new embedded Mark2 profile. You will also need to change platform shift and print area. I'm not sure if Mark2 has the material adhesion option enabled.

But for me the old DXU profile works directly with Cure 4.3, so I didn't find it necessary to do a new version. Did it not work for you?

 

On 10/29/2019 at 2:36 AM, luke199 said:

Hey all,

 

What's the recommended general retraction length and maximum?

I use 6.5mm, 25mm/s, same as UM2+ default.

[Garufa 11]

yyh1002, My bad, when migrating to version 4.0 all my settings became corrupted and could not make it work. I just tried with 4.3 again with your profile and works !!! - thank you.

[Octocom 1]

Thanks yyh1002.  I run some tests and between 2.70 and 3.50 @25mm/s is perfect depending on material

[ddt154 0]

I ran into a problem.  I have converted my UM2E over to 1.75mm and 4/2 bowden.  The top of the one part is fitted to connect with a 6/3 bowden tube.  I was able to use an existing PTFE connector I had and a coupler to mate with the top of the metal tube, however it does not match up with your design.  I also switched over to a BMG feeder and it is all setup to use 4/2 bowden as well.  Any chance you can sent me your housing front in a step or other cad file so I can modify it for my use? 

Edited December 15, 2019 by ddt154

[Anzen 0]

Bonjour

puis cura version 4.4.1
quelle que soit l'extrudeuse que je choisis, c'est toujours extruder 1 qui imprime

 

pouvez-vous me fournir la définition et les fiches de ressources de l'extrudeuse

 

using the DXU cura v3.4 source file in nozzle it displays empty

 

merci

J'ai les fichiers que j'utilise

 

Mark2.zip

Edited January 19, 2020 by Anzen

[Anzen 0]

comme je n'est pas de réponse

je doit modifier le gcode en rajoutant T1

 

;FLAVOR:Marlin
;TIME:1528
;Filament used: 0m, 0.580902m
;Layer height: 0.15
;MINX:104.25
;MINY:96.75
;MINZ:0.27
;MAXX:133.75
;MAXY:126.25
;MAXZ:19.92
;Generated with Cura_SteamEngine 4.4.1
T1
M82 ;absolute extrusion mode
;material_bed_temperature=60 material_print_temperature=215.0 material_print_temperature_layer_0=215.0
M190 S60
M104 T0 S175
M109 T1 S215.0
M104 T0 S200
G21 ;metric values
G90 ;absolute positioning
M82 ;set extruder to absolute mode
M107 ;start with the fan off
M200 D0 T0 ;reset filament diameter
M200 D0 T1
G28 Z0; home all
G28 X0 Y0
G0 Z30 F2400 ;move the platform to 30mm
G92 E0
T1 ; move to the 2th head
G0 Z20 F2400
G92 E-7.0 ;prime distance
G1 E0 F45 ;purge nozzle
G1 E-5.1 F1500 ; retract
G1 X90 Z0.01 F5000 ; move away from the prime poop
G1 X50 F9000
G0 Z20 F2400
T0 ; move to the first head
M104 T1 S175
G0 Z20 F2400
M109 T1 S215.0
G92 E-7.0
G1 E0 F45 ;purge nozzle
G1 E-5.1 F1500
G1 X60 Z0.01 F5000 ; move away from the prime poop
G1 X20 F9000
G1 E0 F1500
M400 ;finish all moves
G92 E0
;end of startup sequence
G92 E0

T1
G92 E0
G1 F2100 E-5.5
;LAYER_COUNT:132
;LAYER:0
M107
M204 S375
M205 X17 Y17
G0 F2400 X108.876 Y96.761 Z0.27
M204 S250
M205 X10 Y10

 

Edited February 9, 2020 by Anzen

[yyh1002 60]

On 1/19/2020 at 4:23 AM, Anzen said:

Hello

then cura version 4.4.1
whatever extruder I choose, it is always extrude 1 which prints

 

can you provide me with the definition and resource sheets of the extruder

 

using the DXU cura v3.4 source file in nozzle it displays empty

 

thank you

I have the files I use

 

Mark2.zip

Hi Anzen, 

Sorry for the late reply. 

There is a critical bug for Cura 4.4.1, which is exactly what you found. It cannot generate correct tool number in start code for dual prints. 

They fixed the bug in 4.5 beta. You can use 4.5 beta now. But I think the first layer path of 4.3-4.5 is not as clean as 4.2.1.

I uploaded new profile for Cura 4.5 to Github. And also an updated version of firmware. 

This new firmware will prevent any tool change when head position is unknown. It avoids the problem of bad start code movement caused by the first "T0" or "T1" generated by Cura which makes the printer to think it's holding a wrong head. 

It works together with a new start code that automatically select and purge the nozzle used in a print. 

The machine "DXU" should be used for single nozzle print, either left or right nozzle. 

The machine "DXU Dual" should be used for dual nozzle print. The difference between the two is start code.

[cvansas 0]

Hi there, 

 

I decided to start building the DXU upgrade for my UM2+ ordered al the hardware parts and polycaronate for printing all the parts. The only doubt I had was that the 35w heater would be on the light side, so I replaced that with a 40W heater set. It might be too much as well resulting in a less sable temperature, but we will see. As soon as all is finished Ill share the results. Furthermore I managed to get most of the parts directly from Aliexpress and some were ordered via Superuser (good taobaoagent) when there was a substantial price difference for the same quality. the price for all was around 110 euro's.

 

Best,

Crispijn

 

Edited March 9, 2020 by cvansas
BOM was incorrect and deleted to prevent confusion

[cvansas 0]

the previous BOM was the unsaved original. Now the edited version with all the parts from 2 aliexpress suppliers: SANBrother and bolts from Nindejin. Please note the following:

 

- as earlier mentioned the Hotend kit from SANBrother is slightly different and requires some adjustment of the original DXU design. 

- Some parts are available on Ali but much more expensive. Primarily the Fans, PI insulator, extruder motor.

 

BOM_aliexpress.xlsx.zip

 

[cvansas 0]

Hi there, 

 

I decided to start building the DXU upgrade for my UM2+, however I noticed that the hotend kit found on taobao is not available at this moment and that the alternative aliexpress variant would differ in size. Therefore I was wondering whether it would be possible to acquire the original design file (fusion 360?) in order to make the necessary modifications to fit the SANbrother hotend. Also I would like to slightly improve the design with snap fit casing, countersunk screws and slightly bigger dimension of the fan part attachment.
 

[yyh1002 60]

 

On 3/12/2020 at 10:10 AM, cvansas said:

Therefore I was wondering whether it would be possible to acquire the original design file (fusion 360?) in order to make the necessary modifications to fit the SANbrother hotend.

 

I've just uploaded the step file, something to play with for anyone interested during the crisis . 

[nvcheeko 0]

What Modifications is needed to use the SANbrother Hotend? 

[dadoblu_2000 0]

hello I would like to make this change to my um 2+ ext, I would like a couple of information, the components can be sampled in abs and possibly know layer height and filling density, in addition I would like to know if it is possible to keep an original olsen as a second extruder from 2.8mm instead of applying 1.75mm model, thanks

[dadoblu_2000 0]

the 3510 12v fans are nowhere to be found, they cost more than the printer, do you have any idea where to find them or if it is possible to put 5v fans?

 

[nvcheeko 0]

1 hour ago, dadoblu_2000 said:

the 3510 12v fans are nowhere to be found, they cost more than the printer, do you have any idea where to find them or if it is possible to put 5v fans?

 

Just quick search. How much u getting ultimaker for, I'll buy more at that price.. 

[dadoblu_2000 0]

1 hour ago, nvcheeko said:

Just quick search. How much u getting ultimaker for, I'll buy more at that price.. 

I don't think they ship to Italy, besides the fans are turbines, not the radials

 

[nvcheeko 0]

Just go on Aliexpress maybe they have blower fans 

[yyh1002 60]

DXU profiles are now included in Cura 4.6 by default.

The profiles in 4.6 is pretty much the same as the one on Github for 4.5.

One for single nozzle print and one for dual nozzle print. 

The postprocessing script is no longer needed.