[Solved] Which Nozzle 0.8?  

RE: Which Nozzle 0.8?

Good Morning Sacha, 
as you are new to the hobby I would suggest that you buy nozzles from E3d the manufacturer of the hot end, first time,

https://e3d-online.com/nozzles-for-3d-printer

the hot end is an E3dV6              https://e3d-online.com/catalogsearch/result/?q=prusa+hotend

as you have a Mk3 or Mk3S printer, the heater will be 24 volts. (future knowledge)

you are planning to use large nozzles, the e3Dv6 has a limited melt capability so you may want to consider getting a SOCK to help retain heat in the heat block              https://e3d-online.com/block-sock-v6-upgrade-kit

the Sock will also help keep your hot end clean and make changing the nozzle easier at a later time. 

there are two types of Sock, the one with the large hole which surrounds the nozzle, is my preferred type.

there is another type, called the 'pro' which has a much smaller hole for the nozzle tip to poke through...    I have tried these and had problems,directly caused by the pro sock...  so My advice is DO NOT get the Pro sock!

If you find that the E3dV6 heat block cannot melt enough plastic to print as fast as you would like, it is possible to replace the standard heatblock and nozzle with 'E3D Volcano'  heat block, nozzle and sock. to increase the melt zone size  (this also requires a modification to th firmware on the printer        https://e3d-online.com/volcano-upgrade-kit

E3D have distributors in many countries, here is a link to the distributors list!    https://e3d-online.com/resellers

If you choose to buy nozzles from Ebay, Amazon, Aliexpress, or elsewhere   MAKE SURE you get the ones intended for the E3Dv6 (or Volcano, if you have upgraded)  because there are a number of similar looking nozzles that have a shorter length of thread, which will cause the extruder to leak plastic around the screw threads.

I suggest that you obtain some heatsink paste to go between the heatbreak screw threads and the heatsink screw threads
I also suggest that you obtain some 'Coppaslip' high temperature paste to go between the nozzle threads and the heat block (If you do this, it will make nozzle changing much easier...)  

there are nozzle changing kits for sale suck as this one                   https://www.ebay.co.uk/itm/Fixture-Wrench-Hexagon-Socket-7mm-To-9mm-Set-3D-Printer-Nozzle-Removal-Tool-Kit/233391318418?hash=item365734e592:g:q0gAAOSwRSBdwSVd

however I have not used this supplier...  NOTE the socket wrench in this kit, it MUCH LONGER THAN NECESSARY.... It will be very easy to break the nozzle if you are a bit heavy handed with this wrench!!!

I prefer to use a spanner like this    https://www.ebay.co.uk/itm/1pcs-Hotend-Nozzle-Wrench-for-E3D-V5-V6-Nozzle-Removal-or-Tightening-NEW-ST/392364536039?hash=item5b5abfb0e7:g:khoAAOSwTLpdQp08

there is a Knowledge Base article on different Nozzle sizes here    https://help.prusa3d.com/article/LND6Zdnks4-different-nozzles

and a guide to replacing the nozzles here    https://help.prusa3d.com/article/fJa7GxLSG6-changing-or-replacing-nozzle

It's probably a good idea to get some additional PTFE Tube for Lining the Cold end between the Bondtech Gears and the Heatbreak

this link directs you to a knowledge base article on replacing the PTFE    https://help.prusa3d.com/article/nt3gmt736i-ptfe-tubes-in-original-prusa-i-3-printers

ready made PTFE tubes are available from Prusa, however having the tools and raw materials available will allow you to make tubes to fit, even if the original extruder design is changed!

I can't stress enough... the Back of the Nozzle MUST touch the End of the heatbrreak, tightly (To prevent leaks)

and There must be a tiny gap between the hex nut on the nozzle and the face of the heat block...

I hope this is not information overload. 

regards Joan

RE: Which Nozzle 0.8?

I've got some notes on nozzle selection and use here. As Joan says, you want to avoid the cheap nozzles. Some notes on nozzle manufacturers and suppliers here.

RE: Which Nozzle 0.8?

Wow! Thank you very much.

So much informations, thank you for the quick help!!!

Best regards 

Sascha