2A. MK3/MK2.5 - extruder disassembly

Relevant for:

MMU2S

Last updated 2 years ago

Difficulty

Moderate

Steps

Available languages

Step 1 プリンタの準備

始める前に確認すること:

⬢the filament is unloaded from the hotend

⬢プリンターが適切に冷却されていること

⬢プリンタのプラグが抜かれている

⬢you removed the steel sheet

This chapter is dedicated only to the MK3/MK2.5 owners. If you have new MK3S/MK2.5S, please follow: 2B. MK3S/MK2.5S - extruder disassembly

The MK3 and MK2.5 have several design iterations and yours might differ from the one used as an example in this disassembly. As a result, some instructions might be not applicable to your printer (you can skip them).

Step 2 Releasing the cable bundle

⬢Using an Allen key release the M3x40 screw and open the door.

⬢Release two M3x10 screws and remove the extruder-cable-clip. On older printers cut the zip tie.

⬢In case there are zip ties inside the Einsy-case, carefully remove them.

⬢Remove the zip ties on the cable holder.

⬢Remove the textile sleeve (spiral wrap) all the way to the Einsy-case.

Step 3 Unplugging the extruder cables

⬢Open the Einsy-case and follow all the cables from the extruder. Unplug them one by one.

WARNING: some cables have a safety latch, don't pull them!

⬢Leave the other cables connected.

⬢MK2.5 requires similar disassembly, follow all cables from the extruder bundle and disconnect them.

Step 4 Removing the filament sensor cable

⬢Release all five screws and remove the X-carriage-back. Be careful with the wires. Disassemble the cable-holder and keep it for the rebuild.

⬢Unplug the connector and remove the filament sensor cable. This is cable is no longer needed and will be replaced with a new one.

⬢Carefully separate the cables and push them to sides.

Step 5 Releasing tension in the X-axis belt

⬢X軸ベルトの取り付けを続ける前に、X エンドの M3 ネジを緩めてください。

⬢写真のように、X軸モーターをフレームの方に少し回転させます。

New version of X-end with tensioner provides easier fine-tuning of the tension in the belt, but you can assemble the printer without it. Printed parts are available at: prusa3d.com/prusa-i3-printable-parts/

Step 6 Removing the extruder

⬢Release both M3 screws.

⬢Before removing the last screw, hold the extruder as it will fall down.

⬢Carefully lay the extruder on the heatbed and push the cables through the X-axis.

⬢Return to the X-carriage:

⬢Remove the black nylon and keep it for later.

⬢Remove the belt and keep it for later.

⬢Cut the zip ties and remove the carriage completely. For the MK3S/MK2.5S you will need a different one.

Step 7 Fans and motor removal

⬢プリントファンを取り外す前に、ノズルファン（ファンシュラウド）が先に取り外されていることを確認します。

⬢Release all screws on both fans and carefully remove them.

⬢アイドラーを固定している両方のネジを外します。

⬢Remove the fan support.

WARNING: release all three screws, but keep in mind the motor will fall off!

After you remove the motor, there will be two translucent washers on the idler, no need to keep them.

Step 8 P.I.N.D.A. probe removal

⬢M3x10 ネジを緩めて外します。

⬢Remove the sensor.

Be careful with the wire!

Keep the sensor for the reassembly.

Step 9 Hotend removal

⬢Release both M3 screws and remove the Extruder-cover so you can reach the hotend.

WARNING: Removing hotend from the extruder needs a "special" technique, then the hotend slides out quite easily. Don't use excessive force, or you will damage some parts irreversibly!!!

⬢The hotend is removed by inclining and pulling at the same time. See the picture showing the WRONG inclination. This hotend is inclined too much to the front and there is no gap between the hotend and the extruder body. Hotend is partly inside and you won't be able to remove it.

⬢The second picture is showing the CORRECT inclination. The hotend is tilted, but there is a gap between the hotend and the extruder body. You will be able to remove it.

Step 10 PTFEチューブの取り外し

このステップは必須です! MK3S/MK2.5SはMK3/MK2.5に比べて短いPTFEチューブを使用していますので、今すぐ交換しましょう！

⬢黒いプラスチックのコレットを(ホットエンドに向けて)押し下げ、そのまま保持します。

⬢ホットエンドから古いPTFEチューブを取り外します。

⬢See the next step on where to find and how to replace the new one.

See the next step on where to find and how to replace the new one.

Step 11 新しいPTFEチューブを挿入する

⬢アップグレードパッケージを開封し、PTFEチューブの入った袋を探します。

⬢新しいPTFEチューブを確認します。両端がきれいであることを確認してください。

⬢さて、いよいよ新しいPTFEチューブを挿入します。端が2つの異なる形状であることに注意してください。

⬢チューブの一端は「ラウンド」のエッジになっています。こちら側がホットエンドの内部に入る方です。

⬢反対側の端をご覧ください、チューブの内側にドリルで内部の穴を処理しています。エッジ内部が「円錐形」になっています。こちら側が、フィラメントがチューブに入ってくる方で、ホットエンドの外側になります。

⬢Push the black collet in. Slide the tube all the way in and hold it!

⬢Using second hand pull the collet out and only then release the tube!!! THIS IS CRUCIAL for the hotend to work properly.

Step 12 Removing the Bondtech gear

EXTRA WARNING!!! Be extremely cautious during this step!!! You can easily strip the lock screw and irreversibly damage it.

⬢First, make sure the Bondtech isn't glued to the shaft. This is valid in case of the pre-assembled printer. If there is a glue, heat the shaft first (heatgun, lighter). Be careful, you can burn yourself.

⬢Second, carefully release the lock screw. If the resistance is too high, use a grease (e.g. WD-40) and wait for a while.

⬢Remove the Bondtech gear from the shaft and keep it for later.