Circuit Board Cooler for Early UM3 (doesn't fit recent models)

This part allows a part cooler blower to be used to cool the print head circuit board

3D printer parts and enhancements

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    Fbrc8 tech support helped me hone in on the heat issue and Joseph provided me with the information on the fan connectors on the main board.


    I was getting errors when printing with Polycarbonate on a fully enclosed UM3 and determined it was a heat issue with the print head circuit board.

    This part replaces the back cable clamp on the print head on an Ultimaker 3. It attaches with the original screws. A side part cooling blower is used to force air over the circuit board maintaining the temperature about the board on a fully enclosed UM3 near what it is on a fully open UM3.

    This prevents communication errors from the print head to the main controller. These errors usually look like "print core #2 (or 1) is taking to long to heat up". The errors also prevent the print from restarting after the print has been paused.

    Some Data:

    This program prints 4 identical parts. 2 in ABS, 2 in Polycarbonate.

    Printer open (no cover no door)
    T=0 32C
    T=7:00 (minutes) 51C (end ABS)
    T=11:00 57.6C (end Poly C)
    T=14:00 59.5C (end ABS)
    T=16:00 61.1C (end Poly C)
    T=32:00 65.8C (end ABS)
    T=49:00 64.8C (end Poly C)

    Printer fully enclosed (starting about 3 minutes from previous ... printer fully warmed up)
    T=0 53.7C
    T=12 76.6C (end Poly C)
    T=40 86.0C (end Poly C)
    T=42:30 84.9C (end ABS)
    T=46:30 85.8C (end Poly C)
    T=50:00 85.3C (end Poly C)

    Printer fully enclosed using fan setting on printer (had to reset fan speed every 30s or so)
    T=10:00 71C
    fan on 50%
    T=11:00 65.2C
    fan off (the fan kept going back to zero)
    T=21:00 fan on 75%
    T=23:00 73.0C (end Poly C)
    T=25:00 74.9C (end Poly C)
    fan on 100%
    T=31:00 71.4C

    Printer fully enclosed, Circuit Board cooling fan on 75% in program from start
    T=15:00 64.6C
    T=45:00 66.0C

    Materials and methods

    Part is printed in Polycarbonate at 0.15 mm step and takes a little over 1 hour to print.

    1: UM3 print cooling blower (can be pulled from print head if you never use print cooling) Also available from Digikey p/n 603-1561-ND (w/o connector) or it is a Delta BFB-03505HHA-A 35x35x10 mm blower.

    2: #2x1/2" screws (self tapping or machine)

    3: Board connector 2.5mm pitch
    Connector Housing 2.5mm 2 position, Digikey p/n 455-2266-ND
    Connector Contact w/ 12" leads, Digikey p/n 455-3241-ND (the connectors take a special crimp tool so getting pre assembled leads is the best option)

    4: 4.5 feet x 2 conductor 22 or 24 gauge wire. (red/black preferably)

    To connect to the main board "FAN A" connector (FAN A turns on with the print core cooling fan. It is on when the print cores are >60C and off when <60C)

    A 0.1 pitch connector is required. (still looking for the part # from Digikey)
    Open the main board cover, Find FAN A connector.

    Locate the side of the connector the "A" is pointed at. This is "pin 1" the side which connects to the red wire on the blower.

    Attach the connector pin one to the red wire on your 2 conductor pair. Attach the black wire on the other side.

    Plug the connector into "FAN A" red wire to pin 1. (towards the identifier).

    Route the new wires along the cable going to the print head. It can be tucked into the clips holding the cable to the bowden tube. Use tape or zip ties as needed.

    Connect the new blower to the long wire, solder and insulate the connection with heat shrink tubing or electrical tape. Electrical tape may come loose with the heat.

    Remove the back cable clamp with the 2 screws at the back of the print head. All 4 screws should be loosened but the front 2 should not be removed.

    Install the new cable clamp/blower mount using the original screws. Tighten all 4 screws.

    Insert the blower into the blower mount and secure with the 2 #2 x 1/2" screws.

    If you don't want to buy a new blower you can use one of the part cooling blowers but this is not ideal:

    Remove the print heads
    Lower the housing containing the side cooling blowers by removing the 4 self tapping screw by the air inlet.
    Loosen the wires to the blowers so they can be unplugged. There is a small coil of extra wire bundled behind the blower. As shipped the wires are pulled tight at the connector but you can allow enough extra to be able to plug them back in without disassembling everything again.

    Reassemble the side fan assembly

    Plug the blower into one of the part cooling blower plugs on the circuit board and restrain the extra wire.

    Use part cooling at 75% fan speed to turn on the circuit board cooler.

    The preferable connection would be in parallel to the print core cooling fan. This requires splicing the new blower into the white and black wires from the print core fan. I have not tried this yet and do not know it the circuit can handle the additional fan. I also need to confirm the polarity of the other that fan connection.



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    E5d7b6d657b362b032a6ddfadf5d624f?default=blank&size=40yonutz33 added this to the For Ultimaker 2/3 collection ago
    74637ddd9c05e8569750b756b7313729?default=blank&size=40Scherdin added this to the Um3 collection ago
    Mini il 570xn.1343682359 2jz9The 3D printing Guy commented ago

    Nice design, pleased that you made it open to the public!

    80e1261db630a76ca6b64b9d114a92fb?default=blank&size=40Larry56 published this design ago