How to replace a heatbed set (MINI/MINI+)

Relevant for:

MINI MINI+

Last updated a year ago

Difficulty

Easy

Steps

Available languages

Step 1 Introduction

⬢This guide will take you through the replacement of the heatbed set on the Original Prusa MINI and MINI+.

Some parts might be slightly differ. However, it does not affect the procedure.

⬢All necessary parts are available in our eshop prusa3d.com

Note that you have to be logged in to have access to the spare parts section.

Step 2 Tools nessesary for this guide

⬢For the following steps, please prepare:

⬢2.5mm Allen key

⬢TX10 Torx key

⬢Universal wrench

Step 3 Opening the box with the electronics

Turn the printer off and unplug it from the socket!

Wait till the heatbed is cold!

⬢Release and remove the M3 screw on the box with the electronics.

⬢Remove the cable cover.

⬢Lift the second electronics cover slightly. Before you remove it completely, pull it first towards the vertical aluminium extrusion to release both pins from the holes.

Step 4 Disconecting the heatbed

⬢Disconnect the heatbed cable.

⬢Press the safety pin on the connector and disconnect the heatbed thermistor cable from the electronics board.

Step 5 Removing the heatbed

⬢Move the Y-carriage all the way to you.

⬢Release and remove 9 screws on the heatbed by using a Torx TX10 key.

Keep all the screws for the next steps.

⬢Remove the heatbed from the printer.

Step 6 Heatbed: parts preparation

⬢For the following steps, please prepare:

⬢Heatbed MINI/MINI+ (1x)

⬢Heatbed cable (1x)

⬢MINI-heatbed-cable-top (1x)

⬢MINI-heatbed-cable-bottom (1x)

⬢Textile sleeve 5x350 mm (1x)

⬢M3x4b Countersunk screw (9x)

The list continues in the next step...

Step 7 Heatbed: parts preparation

⬢For the following steps, please prepare:

⬢M3x12 screw (1x)

⬢M3x8 screw (2x)

⬢M3nN nyloc nut (3x)

Step 8 Assembling the heatbed

⬢Insert two M3x8 screws into the heatbed. Screw heads must be on the top surface of the heatbed.

⬢Turn the heatbed bottom up and place it like in the picture.

⬢Place the red wire (+) on the left screw.

⬢Place the black wire (-) on the right screw.

⬢Attach two M3nN nuts onto both screws and tighten them firmly.

⬢The cable cover, which will be applied later requires the connectors to be slightly inclined towards each other. Hold them in the position as seen in the picture while tightening, but leave a small gap between them. Ensure the cable lugs cant move after tightening.

Make sure the cables are connected properly and the screws are tightened fully. Improper wiring or losing connection to the heatbed can fatally damage the electronics.

Step 9 Guiding the heatbed cables

⬢Guide the black thermistor cable between the heatbed cables.

⬢Wrap the thermistor cable a few times around the heatbed cables (see the photo).

Step 10 Covering the heatbed cables

⬢Insert the M3nN nut into the MINI-heatbed-cable-cover-bottom.

⬢Place the MINI-heatbed-cable-cover-bottom in the bottom of the heatbed cable connectors.

⬢Make sure the connectors fit properly into the cover.

⬢Wrap the textile sleeve around the heatbed cable bundle. Slide the sleeve into the cover as far as possible.

Step 11 Covering the heatbed cables

⬢Slightly tilt the MINI-heatbed-cable-cover-top and slide it over the screw heads on the connectors.

⬢Push the cover to fit properly the bottom part of the cover.

⬢Secure it with the M3x12 screw.

Step 12 Covering the heatbed cables

⬢Slightly pull on the sleeve to make sure it is properly inserted.

⬢Make sure there is no big gap between both covers.

Step 13 Mounting the assembled heatbed

⬢Push the Y-carriage to the front and place the Heatbed behind.

⬢Place the heatbed on the Y-carriage.

⬢Align all 9 holes on the heatbed with the heatbed spacers.

⬢Insert the M3x4b screws in the holes. Don't fully tighten the screws.

⬢After all screws are in place, use the Torx key to tighten them in the following order:

⬢Center screw

⬢First four screws (edges)

⬢Last four screws (corners)

Step 14 Connecting the heatbed cable

⬢Connect the heatbed thermistor cable in the lower connector on the Buddy board.

⬢Connect the heatbed cable in the lower green connector on the Buddy board.

Step 15 Covering the electronics

⬢Before covering the electronics, make sure the square nut is correctly positioned in the printed part. The nut must not fall out! This can cause fatal damage to the electronics.

⬢Insert the cover back in and make sure it is properly seated in the slot. Note: on an older design, there were holes instead of slots, the assembly procedure is the same.

⬢Place the second cover on the top and arrange the cables:

⬢Extruder bundle, ensure the textile sleeve is partially in. Also, it must be tilted away from the printer.

⬢Heatbed bundle, ensure the textile sleeve is partially inside the box.

⬢Filament sensor cable (optional), ensure that the textile sleeve wrapped around the cables is partially inside the box.

⬢Now, tighten the second cover. Check that no cable is pitched.