Improve hotend cooling on duel extruder v2?

I just received my Dual Extruder Tool Head V2. I have not installed it yet as I am considering returning it.

Others have described “heat creep”. Looking at the tiny micro fans used to cool the heat sinks I can see how the problem will occur. I also see that one fan is in contact with one heat sink. The other fan is approximately 3mm away from its associated heat sink.

I’m sure the tool head can work well but the micro fans may require very narrow margins in the setup.

Has anyone found ways to improve the cooling flow for the hot ends?

Increasing speed on the filament cooling fans helps, especially if you’re printing PLA which can handle 100% filament cooling.

My goal for the dual Extruder tool head v2 is for printing ABS+PVA.

If the stock fans are insufficient to prevent head creep, I see a way to get more air with a 12v fan for each hot end.

Question: where can I find the pinouts for the two Extruder harnesses?

The single Extruder tool head is using a 12v hotend fan while the dual Extruder tool head uses a 5v fan for each hotend.

I am assuming there is a 12v fan source in one or both harness. Since the different tool heads use very different pin configurations, it’s not clear which pins I would need to use.

Heat creep shouldn’t be an issue with ABS, just lower temp filaments primarily PLA. The temp of the heatsink barrel gets to the transition point of the PLA when insufficiently cooled.

I’d pair ABS with HIPS as a dissolvable support and similarly PLA with PVA, the extrusion temps are more similar. Hot ABS could melt the PVA.

I tried to print a PVA/ABS print on a V2 dual this week and the ABS did NOT stick to the PVA support. YMMV.

Looking at the design of the TAZ dual Extruder tool head v2, it seems there is not sufficient “separation of duties” to do some combinations well - e.g. PVA+ABS.

The filament cooling is shared by both materials so it’s not possible to cool one extruded filament different from the other.

ABS+PVA should be possible with dual extrusion setups but perhaps the lulzbot has its own set of limitations.

I guess I should concede and just go the ABS+HIPS route.