1c. Parts preparation

Relevant for:

MK3.9

Last updated 3 months ago

Difficulty

Easy

Steps

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Step 1 Tools necessary for this chapter

⬢For this chapter, please prepare:

⬢2.5mm Allen key

Step 2 Removing the heatbed cable cover

In the upcoming steps, you will replace the old heatbed thermistor (from your previous printer model) with a new version that is compatible with MK4S, MK3.9S, and MK3.5S.

If you purchased a new heatbed with the upgrade kit — commonly for users with printers featuring 2+1 screws on the old heatbed — ensure that the new thermistor is pre-installed. You can easily verify this by checking for a white connector at the end of the thermistor cable. The presence of this connector indicates that the new thermistor is already in place and you can skip to M3nEs nuts: parts preparation

This part may vary slightly in the design of the cover, location of the screws and number of the screws.

⬢Remove the screws fixing the cable bundle.

⬢Remove the screw securing the cover. From the underside, grasp the middle M3nN nut with the pliers while loosing the screw.

⬢Remove the cover.

⬢Release the screws fixing the heatbed power cables and remove the cables from the heatbed. From the underside, grasp the M3nN nuts with the pliers while loosing the screws.

Step 3 Removing the heatbed thermistor

⬢From the bottom side of the heatbed, peel off the yellow Kapton tape and silver aluminum tape.

⬢Remove the heatbed thermistor cable from the heatbed.

Step 4 New heatbed thermistor: parts preparation

⬢For the following steps, please prepare:

⬢MK4 Heatbed thermistor (1x)

⬢Kapton tape (1x)

⬢Aluminum tape (1x)

Pay attention to the instructions! The "yellow" Kapton tape tends to curl up and you won't be able to restore its initial shape!!

All the necessary parts can be found in the Heatbed thermistor set bag.

Step 5 Preparing the heatbed and thermistor

⬢After you have removed the thermistor and the tapes, clean the entire board to remove any grease. You can leave the glue, which was under the aluminum tape.

⬢Place the thermistor on the heatbed. The tip of the thermistor must be in the circle.

If you miss this spot, the printer will read incorrect temperature values.

Note which side the sensor is attached to the heatbed.

⬢Take the silver aluminium tape and carefully peel off the protective film.

⬢Glue the tape to the heatbed, BUT ONLY in the centre of the thermistor (inside the circle shape). We need to double-check the correct position.

⬢Peel or bend the tape slightly, to reveal the tip of the thermistor.

Step 6 Covering the thermistor

⬢Maintain the thermistor position and cover it with aluminum tape. Ensure that the whole thermistor sensor is covered with the tape.

Step 7 Fixing the thermistor in place

Now it is time to apply the final "yellow" Kapton tape. DON'T PEEL OFF the entire tape, it will curl up!!!

⬢Peel off about 1 cm (0.5 inches) strip of the Kapton tape and stick it to the heatbed, like in the picture. Ensure the tape is properly connected.

Make sure the Kapton tape does not overlap any screw holes in the heatbed.

The Kapton tape has a bigger area than the silver tape. Make sure the silver tape is overlapped from all sides.

⬢Continue with gluing the tape and stop for a second above the area with the thermistor. Pay great attention to sticking the tape everywhere.

⬢Finish gluing the tape to the heatbed. Double-check the entire surface is properly connected.

Step 8 M3nEs nuts: parts preparation

⬢For the following steps, please prepare:

⬢M3nEs nut (2x)

Step 9 Inserting the M3nEs nuts

⬢Insert the M3nEs nut into the left short extrusion (side without the PSU). Insert the side with the spring (metal plate) first.

⬢Push the entire nut inside the extrusion using your finger.

⬢Use this method for both M3nEs nuts. The exact position of the nuts doesn't matter at this time.

Step 10 Cable clips: parts preparation

⬢For the following steps, please prepare:

⬢Cable clip (7x)

Step 11 Installing the cable clips

⬢Turn the frame like in the picture and focus on the marked area

⬢Take one of the cable clips and hook the side with the clip into the inner groove of the lower longer extrusion. There is a hook on the part, see the detail.

⬢Place the other end of the clip on the underside of the extrusion.

⬢Use more force to push on the bottom side of the cable clip. It must fit into the groove and you must feel it "click" in.

Step 12 Installing the cable clips

⬢Install three clips to the long extrusion.

⬢Install two clips to the short extrusion.

⬢Turn the frame, install two clips to the second short extrusion.

Step 13 PG-front-case: parts preparation

⬢For the following steps, please prepare:

⬢PG-front-case (1x)

⬢Spacer 13x24x2.5 (1x) can be black or white

Spacer 13x24x2.5 can be found in the NEXTRUDER bag and it can be black or white.

Step 14 Assembling the PG-front-case

⬢Place the spacer into the circular recess in the PG-front-case and push it all the way down. Note the correct orientation of the washer.

The side of the washer with the three circles must not face up! Otherwise, the planetary gear won't work properly.

⬢Make sure the washer is pushed evenly into the printed part.

Step 15 Stickers and labels: parts preparation I.

⬢For the following steps, please prepare:

All the stickers and labels can be found in the UPDATE STICKERS bag.

⬢xLCD-cover (1x)

⬢PG-front-case (1x)

⬢xLCD-cover MK3.9 sticker (1x) rectangular shape, optional

⬢PG-case MK3.9 sticker (1x) square shape, optional

⬢Serial number label (1x) silver label

The list continues in the next step...

Step 16 Stickers and labels: parts preparation II.

⬢For the following steps, please prepare:

All the stickers and labels can be found in the UPDATE STICKERS bag.

⬢Safety label (1x)

⬢Cleaning pad (1x)

Step 17 xLCD-cover sticker (optional)

This and the following step are optional. Also, please BE PATIENT, smaller letters require more effort in order to be transfered and glued properly.

⬢Using the cleaning pad, clean the side without the circle hole on the xLCD-cover.

⬢Peel off a piece of the protective layer and carefully glue the sticker on the xLCD-cover. Maintain the sticker aligned with the edges of the display cover. Start on the bottom side.

Notice the white PRUSA lettering through the sticker. Compare the orientation with the second picture.

⬢After gluing the sticker, run your finger along the entire length of the sticker in all directions to ensure perfect adhesion.

Step 18 xLCD-cover sticker (optional)

This process requires patience and care. Perfect adhesion depends on proper degreasing of the part and the ambient temperature.

⬢Start slowly peeling off the application layer. Lightly press the layer onto the lettering as you peel it off. Observe whether all the letters are glued on.

⬢After peeling off the application layer, check that the final look matches the picture.

Step 19 PG-case sticker (optional)

This and the following step are optional. Also, please BE PATIENT, smaller letters require more effort in order to be transfered and glued properly.

⬢Using the cleaning pad, clean the front side of the PG-case.

⬢Peel off a piece of the protective layer and carefully glue the sticker on the PG-case. Maintain the sticker aligned with the edges of the cover.

⬢See the detail to ensure the correct orientation of the sticker. Use the screw holes as a guide.

⬢After gluing the sticker, run your finger along the entire length of the sticker in all directions to ensure perfect adhesion.

Step 20 PG-case sticker (optional)

This process requires patience and care. Perfect adhesion depends on proper degreasing of the part and the ambient temperature.

⬢Start slowly peeling off the application layer. Lightly press the layer onto the lettering as you peel it off. Observe whether all the letters are glued on.

⬢After peeling off the application layer, check that the final look matches the picture.

Step 21 Sticking the serial number label

This step is required in order to provide warranty! Don't throw the label away!

⬢Peel off the protective layer from the rear side of the label.

⬢Glue the label on the left side of the rear plate. Make sure, the surface is clean. Use the supplied cleaning pad.

Step 22 Safety label (optional)

⬢Take a look at the front side of the printer frame. There should be a yellow safety label on the right side of the frame.

⬢Peel off the label.

⬢Use the supplied cleaning pad to wipe the area where the label was applied.

⬢Take a new safety label. Peel off the bottom protective layer from the label and glue the label on the clean surface of the frame.

Please note that the following pictures in the manual were taken with a previous (yellow) version of the safety sticker. This is because they were taken before the new sticker was available.