Any ideas of how much torque I would need for 1.75mm Filament direct drive?

Any ideas of how much torque I would need for 1.75mm Filament direct drive? Without gears btw. Found this one:

Its 0.9° so I get more resolution out of it. Saw some extruder with this but some experiences would be nice. Its going to be dualextruder (chimera) as directsetup. This would not only be lighter but smaller. Has to be Nema17 btw.

Eh, depends on what sort of filament with what sort of hotend at what speeds you want to print and what sort of drive gear you use.
In the end, though, it’s not about the size of a stepper motor, it’s about how hot you want it to get. In almost all 3D printers, you’re running the stepper motors at a fraction of their rated current, which is why they don’t even get warm to the touch in most machines.
If you get a motor with a lower rated current and torque, chances are it will perform practically identically to a larger one with higher ratings if you don’t change the driver setting as well.
It will just run hotter, which might be something to worry about.
Now, personally (ie without data to back it up) i wouldn’t be comfortable running motors smaller than 30mm for a direct-drive 1.75mm extruder, as the extra heat can soften up the filament too much if not controlled correctly. In my experience, direct-drive extenders do need at least 1A to work reliably in most scenarios.

The direct drive ungeared extruders in all the Replicator 1/2/2x and clones (like 100,000+ printers) is a 30 N-cm holding torque short-stack NEMA 17 driven at 0.75-0.85A in a rated current of 0.84A, with a 10.5-11mm hob diameter. Moons 17HD-4063-xxN. Prints just fine. It stalls before stripping the filament grip, which is nice. They don’t win any extrusion speeds records but they’re solid little performers. Not suitable for PLA mounting brackets though.

@Thomas_Sanladerer yes was more asking about a gestimation. Well thats a word tom. Would use a big one but two big ones? Well nah. Its for all filaments and speeds up to 100mm/s just like now. Just dualextrusion :wink:

@VolksTrieb 11Ncm is pretty low, I probably wouldn’t go below 20 unless you gear it down.

Thank you for your answers! Well seems like the short nema17 wont work out even if they could. Only got 12V and even if the driver would output 12V its just the max current. Nah need to use a 39/40mm one. But that barely fits lol.

There you have it. The red “circle” is where the endstop should sit. Either I move the endstop to the Z-Axis-Braket or need to change its position. Got 9mm (18mm distance from nozzle to nozzle) of the chimera left over to work with omg.
missing/deleted image from Google+

Some people use cooling fans on their cold end motors so that the motor does not heat the filament too much when you crank up the amps.
There is a cold end design that uses two “pancake” motors like that one to push the filament on both sides. I do not recall the name. Perhaps someone else can provide the name and a link.