What went wrong

I bought my prusa i3 from China, nice looking acrylic body. It's head was leaking some plastic between heating block and heat sink. Manufacturer told me to clean and reassemble it. I looked for a cleaning agent and someone adviced NaOH, I use PLA. Result is pic related.

What should I do next time? What cleaning agent do you advice?

If I manufacture my heat sink, from which material should I make it?

What should I do to solve leaking? Could putting some teflon band around the screw solve the issue?

Perhaps next time, heat the head up to a good temp... say 230C and then with two wrenches (one on the block and one on the tip) snug them up together as best as you can. Then let it cool. Then load the PLA and test.

This is the instructions that came with my E3D V6 Lite and it seemed to work for me.

Teflon band is also a thermal insulator and that wouldn´t be a good idea between nozzle and the hotend.

A good but nasty solvent is methylenchlorid a.k.a. dichlormethan.

A new hotend should be from aluminum.

I had a clogged hotend once and screwed off the nozzle. Then I heated the nozzle with my solder iron and pulled out the clog. No chemicals neccessary at all.
-Olaf

Edited 1 time(s). Last edit at 06/20/2015 04:45AM by o_lampe.

Hi

Burn the plastic out with a flame, use the gas cooker. Then brush correctly, care it will smell bad, black smoke, and liquid plastic.
Like that the plastic became very easy tu brush or scratch.

Don't use tape or other stuff or old plastic will stay in your nozzle and u will get problems. Jam, nozzle reduction, black spot in your prints....

When install, first screw the nozzle till max then unscrew it 1 turn.
Install the threaded rod with ptfe tub on the other side until it touch the nozzle.
Then tight hard the nozzle. Using pliers on the heat block and one on the nozzle.

After 1 st used, let it cool down and then check again. Nozzle with heat block