This manual is for the Original Prusa i3 MK3 only! In case you have a new model MK3S+, please proceed according to Original Prusa i3 MK3S+ kit assembly.
Fantastic kit - best one I have ever worked with, and I’ve been building electronics kits for 50+ years, including many of the famous HeathKit series, and this one was by far the best documented I’ve ever seen.
Some thoughts for first-time builders:
1. Get a set of ball-end metric hex -key (allen wrench) drivers like this one (https://www.globalindustrial.com/p/tools/hex-keys-and-drivers/ball-end-screwdrivers/set-6-balldriver-screwdrivers-15-5mm-10686?infoParam.campaignId=T9F&gclid=Cj0KCQiA-JXiBRCpARIsAGqF8wVLX3IOR5gKLdw9hNfwunbuiPaUTr0JiVTes1qEAWk5Zrv72bcnGmgaAjJoEALw_wcB). While the allen wrenches included in the kit are adequate, using them gets old in a hurry.
2. Use the online assembly manual instead of the printed version, and read the comments associated with each step BEFORE performing the step. Many of the comments are from builders who got that step wrong or had (and solved) problems. Reading the comments will save you a lot of time and frustration.
Fantastic kit - best one I have ever worked with, and I’ve been building electronics kits for 50+ years, including many of the famous HeathKit series, and this one was by far the best documented I’ve ever seen.
Some thoughts for first-time builders:
1. Get a set of ball-end metric hex -key (allen wrench) drivers like this one (https://www.globalindustrial.com/p/tools/hex-keys-and-drivers/ball-end-screwdrivers/set-6-balldriver-screwdrivers-15-5mm-10686?infoParam.campaignId=T9F&gclid=Cj0KCQiA-JXiBRCpARIsAGqF8wVLX3IOR5gKLdw9hNfwunbuiPaUTr0JiVTes1qEAWk5Zrv72bcnGmgaAjJoEALw_wcB). While the allen wrenches included in the kit are adequate, using them gets old in a hurry.
2. Use the online assembly manual instead of the printed version, and read the comments associated with each step BEFORE performing the step. Many of the comments are from builders who got that step wrong or had (and solved) problems. Reading the comments will save you a lot of time and frustration.
for this assembly you will need following Allen keys (all are included):
1.5 mm - pulleys
2.5 mm - M3 screws
3.0 mm - M5 screws (aluminium parts)
Regarding the recommended torques, there aren't any specific values. My recommendation is to make the final tightening using your hand and keep in mind, it is a plastic part you are tightening, not a steel.
If you are unfortunate enough to have received the wrong PINDA probe for the MK3, but fortunate enough to read this: Check the PINDA probe for Chapter 5 - step 28 now. If it has 3 wires as opposed to 4, and you are assembling a MK3, you’ll need to contact Prusa for a replacement. If you don’t check this, you won’t discover it until you’re 3 connections away from being done and will have to do extra work and wait to replace it. DO IT NOW.
