Dual extrusion on UM2

[Roland 31]

I'm looking for a team that is interested in dual extrusion on UM2.

To realize dual extrusion on this machine the team should have skills like:

-programing firmware (using actually tinkergnome firmware)

-Plugin for Cura

-people testing the equipment.

-CNC programing/milling ->that's me.

Main issue in dual extrusion is oozing.

To fight that problem I have created a tiny aluminium chiller and a new design for a really fast heater block.

To prevent oozing it is necessary to decrease the temperature of the inactive tool by ~40°, depending on the filament you are using.

In my design the aluminium chiller replaces the small fan , the cooling rib and the bottom hot end holder in the tool head (it makes no noise when idle:))

At the beginning I made test with Olsson block and was disappointed because of long cool down and heat up times.

In the next step I did a redesign of the Olsson block.

1st: Having the extruded material exactly between heater cartridge an PT100 sensor.

2nd: Reduce thermal mass.

3rd: Reduce weight.

Now I'm at a point where I need your help.

The firmware of the printer needs to be improved.

The way I would prefer is:

add a new variable to the file "Material.txt" called "idle_temperature" this variable is stored with each material in the printers software. It should be possible to edit the value online.

When printing a part and there is a tool change ahead, the printer should move to tool change position and heat up the new tool, cool down the inactive tool.

Example:

G1 F900 X103.178 Y39.538 E193.22154

G92 E0

G10 S1 ;retract before tool change is already implemented

G1 Z0.275

T1 M6 ; M6 = move to tool change position -> heat up / cool down extruders

G0 F9000 X75.509 Y72.471

;TYPE:SUPPORT

G1 Z0.200

G11

G1 F1200 X75.509 Y81.131 E0.69280

G1 X66.849 Y81.131 E1.38560

G1 X66.849 Y72.471 E2.07840

If you are interested, I can provide you:

-A set of heater blocks, replacing Olsson or standard heater block (without nozzles).

-CNC milled dual head chiller. with 2 tube connectors 4mm

-A light weight fan holder as stl file or printed in Polymaker PC-Plus /black .

The cost for a set of heater blocks + water cooled chiller will be 120€.

You need of course a second extruder with all parts leading to the tool head.

A external 80mm aluminium chiller 12€

A brushless water pump. 4€.

Greetings Roland

[Roland 31]

 

[neotko 1,417]

Bumping this so more people see it. Really interesting!