[Vilyoo]

This is the old configuration. I made a new housing for the new motor.

[joeavaerage]

Hi,

Well, I only need the maximum torque at low speed 0-50rpm because I wind flat wire 5x5mm. My nema 34 12nm is not strong enough

Now you are talking!! This is much more realistic. With 5x5mm wire I can well imagine you want or need 50Nm to wind but your sure as hell don't need to wind at hundreds of rpm either.
That suggests a deep reduction gearbox, something like I pictured before with say a 50:1 reduction. Then a 2000rpm motor would give you 40rpm....which is still fast if winding big
wire.

You could use a motor direct, but the motor would have to be huge and therefore costly.

I think you need a motor with a gearbox for high torque/low speed, ie big wire AND another motor perhaps with a modest gearbox that could go much faster with low torque for smaller wire.

Craig