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MK4 nozzle replacement  

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YigalB
(@yigalb-2)
Eminent Member
MK4 nozzle replacement

According to Prusa's guide ( https://help.prusa3d.com/guide/how-to-replace-the-prusa-nozzle-mk4-mk3-9_421215 ), replacing MK4 nozzle requires taking out the hotend, disconnecting wires etc. This is also the guidance I got fro Prusa's tech support.

On the other hand, I can see a simpler method, which is simpler, like this: 

If so simple, why wouldn't Prusa suggest it?

Posted : 07/08/2024 2:58 pm
JP Guitars
(@jp-guitars)
Reputable Member
RE: MK4 nozzle replacement

Because some people are incredibly ham fisted and are going to break things, the recommended way is the least risky way of changing the nozzle. If you have a modicum of mechanical sympathy then the quick way if fine.

Personally I use a 13mm open end spanner to hold the block and a mini socket set to turn the nozzle, the only time I use the recommended way is if I want to switch to a hardened nozzle as a use a converter to use a V6 Nozzle and I have a spare heater block permanently setup.

Posted : 07/08/2024 3:34 pm
YigalB
(@yigalb-2)
Eminent Member
Topic starter answered:
RE: MK4 nozzle replacement

 

Posted by: @jp-guitars

Because some people are incredibly ham fisted and are going to break things, the recommended way is the least risky way of changing the nozzle. If you have a modicum of mechanical sympathy then the quick way if fine.

Personally I use a 13mm open end spanner to hold the block and a mini socket set to turn the nozzle, the only time I use the recommended way is if I want to switch to a hardened nozzle as a use a converter to use a V6 Nozzle and I have a spare heater block permanently setup.

I would think that disconnecting the cables, pulling out the heater block while removing the cables from their hidden place, and then reverse the actions is more error prone. Also, the YouTuve video shows printed sets to help maintaining the heater block location. 

I will try this, once I will get my MK4 back to work.

Posted : 07/08/2024 4:33 pm
JP Guitars
(@jp-guitars)
Reputable Member
RE: MK4 nozzle replacement

The biggest risk is breaking the wires due to not holding the block sufficiently, particularly the thermistor cable. But I do think Prusa are being over cautious.

Posted : 07/08/2024 4:44 pm
YigalB liked
fabnavigator
(@fabnavigator)
Estimable Member
RE: MK4 nozzle replacement

Changing the nozzle on the MK4 is super easy and should take no more than a minute or two at the most. I change my nozzle frequently.

1. Unload the filament.

2. Flip the fan to the side.

3. Remove the silicon sock if you have one.

4. Loosen the two thumb screws.

5. Attach the MK4 Nextruder Nozzle Change Heater Block Clamp

https://www.printables.com/model/624027-mk4-nextruder-nozzle-change-heater-block-clamp

6. Unscrew the nozzle using the Nextruder nozzle wrench V2, or some other tool of your choice.

https://www.printables.com/model/623570-nextruder-nozzle-wrench-v2

7. Screw in the new nozzle and tighten it.

8. Remove the heater block clamp.

9. Tighten the two thumb screws.

10. Reattach the silicon sock.

11. Flip the fan back into place.

Posted : 07/08/2024 8:20 pm
YigalB liked
fabnavigator
(@fabnavigator)
Estimable Member
RE: MK4 nozzle replacement

 

Posted by: @fabnavigator

Changing the nozzle on the MK4 is super easy and should take no more than a minute or two at the most. I change my nozzle frequently.

1. Unload the filament.

2. Flip the fan to the side.

3. Remove the silicon sock if you have one.

4. Loosen the two thumb screws.

5. Attach the MK4 Nextruder Nozzle Change Heater Block Clamp

https://www.printables.com/model/624027-mk4-nextruder-nozzle-change-heater-block-clamp

6. Unscrew the nozzle using the Nextruder nozzle wrench V2, or some other tool of your choice.

https://www.printables.com/model/623570-nextruder-nozzle-wrench-v2

7. Screw in the new nozzle and tighten it.

8. Remove the heater block clamp.

9. Tighten the two thumb screws.

10. Reattach the silicon sock.

11. Flip the fan back into place.

I should have mentioned that you need to wait for the nozzle to cool to room temperature after you unload the filament. Your time is still only about a minute, but if you need to unload the filament there are several minutes waiting for the nozzle to cool down.

Posted : 08/08/2024 11:12 am
YigalB liked
YigalB
(@yigalb-2)
Eminent Member
Topic starter answered:
RE: MK4 nozzle replacement

With Prusa mini, the nozzle should be hot while unscrewing it, in case some filament was purged.

Doesn't it have to be the same here?

Posted : 08/08/2024 12:08 pm
JP Guitars
(@jp-guitars)
Reputable Member
RE: MK4 nozzle replacement

Nope, mk4 you change cold

Posted : 08/08/2024 12:10 pm
JP Guitars
(@jp-guitars)
Reputable Member
RE: MK4 nozzle replacement

Should have said, that is because mk4 (and XL) use the nextruder

Posted : 08/08/2024 12:12 pm
YigalB liked
YigalB
(@yigalb-2)
Eminent Member
Topic starter answered:
RE: MK4 nozzle replacement

 

Posted by: @jp-guitars

Nope, mk4 you change cold

I am curious: why? Perhaps becauze the nozzele is one long metal piece, unlike the plastic tube leading to the nozzle with the MINI?

Posted : 08/08/2024 12:13 pm
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