Printing With TPU

With the MacEwen extruder installed I figured I should be able to print TPU. I did a lot of searching for general articles and videos and I think I found the right combination for printing with TPU. I purchased a kilogram of TPU from Hatchbox and here's what is working for me:

• Use a higher nozzle temperature - 230C for the first layer then 220C for the rest.
• Print SLOW - I'm using 25 mm/sec with half of that for the first layer.
• Turn OFF retraction - It's too much to ask any extruder to try to push and pull that wet noodle that TPU resembles.
• The stock Ender 3 bed works fine. Nothing other than keeping it clean is necessary. I use 50C for a bed temperature and I've found that if you let it cool down to 40C it's pretty easy to peel off (and that's a good description of the method) the part.
• Expect stringing - They're pretty easy to deal with so it's better to deal with them than wrestle with retraction settings.
• BIG filament boogers - You will get a lot of ooze of the filament before things start printing. Be ready to wipe the nozzle before it sets down to start your print.
• REALLY stringy threads. You get these all over and particularly at the end. It can stretch out so thin that spider web silk seems huge. It's just a minor annoyance and one I'll gladly accept for all the unique things you can do with TPU.