Dual Head V3 VERY inconsistent

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Joined: Wed Jan 03, 2018 4:17 pm

Dual Head V3 VERY inconsistent

Post by ngreeney » Thu Jun 14, 2018 4:07 pm

OK, Love how great our Taz 6 single extruder works. Prints amazing thing!

The Dual Head V3 has been the bane of my existence! 95% of the time prints come out like

Basically it seems that everything we print after the first couple layers one or both filaments will be jammed due to heat creep. We then swapped out the fan for a larger 80mm fan on the heat sink with a funnel. Seemed to help a bit. It only printed PolyLite PLA with 50% chance of printing a single color. Turns out one of the gears that pushes the filament had become stripped due to all the jamming so they swapped it out for a new printer head due to the issues with the extruders not holding temperature.

Turns out the new printer head has NO improvement over the last one.

Any thoughts on what to do at this point or should I just give up on the Dual Head?

Posts: 4
Joined: Sun Feb 25, 2018 9:06 pm

Re: Dual Head V3 VERY inconsistent

Post by tbilan » Sat Jun 23, 2018 6:11 pm

I had a similar issue. The temperature was uncontrollable and they have a recall on V3 heads. If you want to fix it yourself there are the instructions they sent me that worked. I soldered mine and the temperature variations went away after.
I've been following the repairs and they've been soldering the pins on the repaired units. If you are interested in trying to fix the issue yourself I do have a guide for tightening the pin connections on the toolhead. If we can get a better connection between the thermistor wire and the pin it connects to, it might solve what we are seeing. Here are the steps to do so:

1. Turn the printer off, and disconnect the toolhead.

2. Take off the fan shroud around the nozzle. There should be 3 screws that connect it to the body. Once you have disconnected that, find the connector for the thermistor. I have attached a photo of what it looks like.

3. Unplug the connector, and hold the side that has two pins. You will want to follow step 1 through 3 of this guide: https://ohai.lulzbot.com/project/molex- ... e-repairs/

4. Once you have pulled the pin out, it is time to tighten the crimped wires. Take a pair of needle nose pliers, and clamp where the wire meets the pin. You do not want to break anything, but you want it to be tight.

5. Do the steps above for the second pin.

6. Once you have made sure that both are tight, follow steps 9 and 10 of the previous guide to re-pin it.

7. Put back together the toolhead, and try another test. We should see more consistency, and less errors.

This procedure does carry little risk of damaging other components on the toolhead, but just in case other components are damaged (such as accidentally cutting another wire on the toolhead) I need to give out our standard disclaimer for repairs:

WARNING: At Aleph Objects, Inc. we respect your freedom to modify your LulzBot 3D printer. It is important to know that any modifications or attempted repairs that cause accidental or intentional damage are not covered under the Warranty.

Note that we have seen this procedure fix this in a majority of cases, but as per our service bulletin on the issue we have found a solder connection to work better, so we do recommend sending the toolhead in for repair.

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