broken Hexagon hotend?

[dollarz81]

So i got my i3v assembled and calibrated and started printing the first small box. During the print I noticed plastic filament coming from between the hotend and the hexagon heat sink. Pulled everything apart and cleaned up the plastic and noticed the heat sink spins freely around the shift that comes from the hotend, but it seems the hotend and the heat sink cannot be seperated. Is the hot end broken??

[dollarz81]

Colin from Makerfarm says that its normal for some filament to be extruded. Everything is working I suppose.

[printbus]

If the hot end cooling shroud was installed as provided, it could be that what you're seeing is just part of the cooling shroud melting. Some of us now cut away the flat part of the shroud that sits above the aluminum block. IMO, that's almost a necessity when you're printing at higher temps.

Did you retighten the hot end when it was at temperature? That's a good practice to ensure it's tight.

If there is actually a leak, gently clean the mating surfaces of the nozzle and the heat break tube by circling them on a piece of very fine sandpaper laying on a flat surface. That'll remove any small burrs that could be there from manufacturing.

On the spinning heatsink, there's a picture in http://3dprintboard.com/showthread.p...eak-my-hot-end showing what the disassembled hot end looks like. There does just seem to be a long tube that slips into the heatsink.

[old man emu]

There was a tip earlier on in the life of the MakerFarm i3 which involved setting the extruder thermistor into its hole with muffler paste. Maybe a smear of muffler paste on the mating surfaces would fill the uneven areas and prevent the leak?

OME

[dollarz81]

I don't have the fan shroud installed. I cleaned everything and tightened everything while it was hot and there is still a small leak. I'll suppose I'll replace the hotend in a few weeks anyways.

[dollarz81]

So ive taken the hot end is still leaking from the top threads. Could I wrap the threads with kapton tape to stop this?

[dacb]

I believe the Hexagon has to have a cooling at all times and if you have no fan or a fan without a shroud, it may get too hot. Side effects could include warping of the extruder, carriage and possibly the head itself so that it might not seal. Are you running PLA or ABS temps?

[printbus]

I took advantage of a hint that I read somewhere - PLA really likes to stick to itself. I heated up metal parts with a hot air gun to melt/soften the PLA and then dabbed them with a piece of filament, with wadded paper towels used to hold down the part. A stick pin was used to clean out accessible threads while the filament was soft. I've never had a truly plugged nozzle, but I have cleaned mine out by finding the right size wire strand removed from stranded wire. Another hint I had read about. Others have used a guitar string.

[gmay3]

dollarz81, you should definitely be running the fan and the fan shroud at all times, PLA or ABS. I have had my fan stop and all of the above happened that dacb mentioned.

There is a good chance that if you run the fan with the shroud, it will solidify the leaked plastic in the top threads and seal the leak. If you find that this doesn't help, and are planning to get a new hotend anyway, experiment a little and try OME's fix above. Another thing you can try is sealing it with small amount JB Weld. I haven't tried it but it claims to be heat resistant up to 500F so in theory you should be able to print ABS no problem. You might want to get new hotend if/when you wanted to print higher temp materials.

[clough42]

The Hexagon, like other all-metal hot ends tends to loosen when heated, because the aluminum block expands more than the stainless tube. Colin shows in his video how to tighten the hot end, but you really need to tighten it when it's at temperature for it to stay tight.

Just heat it up and tighten it with a couple of wrenches and you should be good.