PRINT IMPROVEMENT

I recently had major problems with stringing on prints with all materials. Using defaults settings, cleaning the hotend and rebuilding did NOTHING to help.

I bought a new hotend and heater/thermocouple and assembled them in the following manner;

  1. First off I bought some high (350 degrees ~C) temperature thermal paste, and some aluminium powder (used in flash powder).

  2. I mixed the Al powder with some of the heat paste and applied this to the heater and thermocouple before inserting them into the hotend block.

  3. I applied some car exhaust sealant to the filament feed tube where it enters the hotend Al block (this stops oozing from this point when the head gets hot and expands).

  4. I put some heat paste on the throat of the hotend tube where the finned heatsink with the fan attaches (to help keep the heat break cooler).

  5. I reassembled the whole print-head and printed a test piece.

The result was NO STRINGING, the extruder heated up a LOT faster than before and the print quality is now as good as a moulded part (IMHO)!!

Layer adhesion is greatly increased and overall strength of the print seems around twice what it was before.

Hope this helps someone.

Zsuite STILL need a retraction setting that the user can define as some problems simply cannot be cured with this mod.

1 Like

I was wondering about thermal paste.

Zsuite has retraction settings (how much to retract and speed of retract), switch to external materials (you can of course still use zortrax filament)

Thanks, I’ll try using the external material settings.

SeanG_65, Thanks for an actual useful suggestion!

Your post got me motivated to go after my leaky hotend. Got it disassembled and cleaned up, ready for reassembly after procuring heat sink paste and exhaust sealant.

Note on the exhaust sealant - after a lot of research for the past 24 hr, I have discovered why it leaks at the top. It is due to a lack of sealed end to end fit between the heat break tube and the nozzle’s threaded end. Stack up problem. I’m trying to sort out presently, but it looks like if your nozzle contacts bottom of Al heat block, odds are you don’t have an effective seal and you will see burnt filament coming out the top at the tube’s retaining flange.

I’m also wondering if this lack of proper seal doesn’t cause mat’l to burn up in the filament pathway creating blockages in a short period of time.

It will surely increase performances…but what about when you have to disassemble extruder for cleaning ?
The heater/thermocoupler will be glued in the hole and very hard to take off

robysoldtamiya -

The heater and thermocouple are not glued in place. Each is held in place by a set screw.

What rrroadster says.

The thermocouple and heater are set in heatsink compound. NOTE ONLY USE high temperature heatsink compound. Most is rated to 200 degrees and will dry out. You need 350 rated. Not cheap but you will definitely see a difference in print quality.