Q is proportional to dT, but even with a peltier dropping the air temp 20 C (impressive, at the airflow rates we'd use), you're only increasing the dT by 12-15%, so you only remove heat 12-15% faster. You'd probably be better off increasing airflow rate instead

Hmm, when you put it in thoughtful terms, as opposed to me just staring at my peltier modules and videos of ian's winder, I think you have a point. I was fixated on the thought "mimic what I saw an industrial machine do" which was cool rapidly with water. But as you worded it, and frankly in general, peltier wouldn't do much.  They are both *awesome* devices, and often underwhelming devices.

Actually, that was the second point of my thread. I was hoping to ask "is there any point to cooling it faster?" in addition to "if anyone wants to try this, I have this to offer" 

Now that you encouraged me to think more analytically,
In general it seems to me that if you want a faster cooling filament there are some improvements that could be made. For one, a short tube so that the airflow goes along the filament for a little bit would result in a cooling that has a greater surface area interaction. Or, just redirecting the airflow of a square fan into a more rectangular profile.  Then, of course, more airflow can help as well (squirrel-fan or doubled up fans?)

I did get one PM about someone interested, so I'll still be happy to send it to them and maybe in the worst case they will use it for something else  if it proves useless (not a bad worst case.)

Q is proportional to dT, but even with a peltier dropping the air temp 20 C (impressive, at the airflow rates we'd use), you're only increasing the dT by 12-15%, so you only remove heat 12-15% faster. You'd probably be better off increasing airflow rate instead.

But by all means - try it out!

What would the goal of cooling filament faster be?

*(I can't recall what machine I got the modules from, I believe it was a string of 8-12 peltier modules per 48V supply, so 4V nominal I suppose and several amps of max power. These are probably 30-40W peltier modules, which of course suggests the power numbers to be off. They're 30mm square with a Ac resistance of ~0.22ohms)

If more than one person is interested, I can ship off two each to two different people. I just have a few of them and would I supply shipping of course. I probably won't buy the filastruder for a few days, nor would I get it for over a month, and I'm already curious what might be done with it.

Overall these are only worth $3-4 dollars each, but I'm hoping to entice someone, knowing there's no effort (or frankly obligation) to signing up for them.

I should add that you will need a DC power source for the peltier modules, a heatsink and fan for the hot end, and probably a shroud of some sort to direct the colder air at the filament. But the shroud might interfere with the filament, I don't know yet.