Sorry if this is a sidetrack but I see two people with TPU experience so here goes: I plan to print rubbery feet for a project and am a bit overwhelmed with the TPU options. Do you have a recommendation for a good TPU or a vendor who carries generally good quality TPU?
I think I need something around Shore A70 or D12, something like a smartwatch band.
I have an Ender 3v2 that I upgraded to a direct drive specifically for printing TPU.
Michael will be a better source of info. I have only two prints under my belt.
I was just looking for a cheap option on Amazon for my ink stamps. I purchased the Overture filament. Not the cheapest but pretty close.
I have printed with Ninjaflex and Overture. The Overture is, I think, a little harder. This is what I bought:
Reading the description: Shore 95A. Ninjaflex is Shore 85A. So I was right.
I currently print TPU (either kind) at 30 mm/s, but I’m using a volcano hotend and a 0.6mm nozzle with 0.45mm layers, driven from an orbiter with dual drive gears. For a standard v6 hotend, you might need to go slower; 15-20 mm/s. It might be possible to go a faster with a CHC hot end — there are 115W CHC hot ends that are compatible with volcano nozzles. I’ve been pondering switching to a CHC hot end in my printer with the 0.6mm nozzle and seeing how fast I can print that way. But the combination of 0.6mm and volcano makes TPU print in non-geological time.
I used both Ninjaflex and Overture to make furniture feet. They have successfully kept my couches from sliding across wooden floors. I would expect either to be OK for your purpose. I don’t think that the softness is actually a big part of its coefficient of static friction; I think that’s a characteristic of the polyurethane itself.
I make sure to keep it dry. I don’t know if it’s necessary, but I print it from my drybox as well as drying it out in my filament oven (a box made out of insulation with an old heated bed and an old 8-bit controller running it). Before I had filament drying capability, my Ninjaflex would spit and bubble a bit. (I’ve had the Overture only since last November, after I started drying filament reflexively.)
Here’s an example of print quality I’ve gotten:
That line on the corner is the seam; I haven’t tried to tune it to reduce the seam; I just don’t care enough.
This is a bumper on spiral stairs to protect heads from a square end of oak. It has low infill and rounded edges to be squishy.
I print TPU, like PETG, on a PEI bed with hairspray as a release agent. It can bond pretty tightly to clean PEI.
Thank you for the info!
The printer I’ll use has one of the all-metal direct drive micro-swiss units with v6 nozzles, usually 0.6mm. It does have a magnetic PEI sheet so the hairspray is a good tip, thanks.
Unless I’ve just opened a filament roll I try to give it a couple of hours in the dryer. A dehydrator keeps the workshop pretty dry, too. When I print TPU I’ll probably feed it directly from the dryer.
I’ve ordered the Overture TPU so I’ll see soon enough how it goes.
Curious how well this worked for you, since I saw you are getting close to shipping the Altos off… 
I went with an off the shelf solution instead of printing the feet so I haven’t printed any TPU, yet. I plan to mess about quite a bit in may, including some TPU tests.
