زنبرك، مطحنة مقاعد عالية العزم

Mine arrived at 33mm uncompressed as listed, and the closed ends sit flat against the retainer without any wobble. Six coils with that 1mm wire feel exactly right for the spindle return on my 6550, and the 14mm coil diameter slipped on clean without binding.

The 1mm wire diameter feels sturdy enough for my mill's quill return, and the closed ends sit perfectly in the spring pockets. Installed it last night and the Z-axis now has consistent tension throughout the travel.

The 33mm uncompressed length was exactly what my mill needed, and the 1mm wire feels sturdy enough to handle repeated cycles. Six closed-end coils seated perfectly without any wobble. This spring fixed the tension issue I'd been fighting for weeks.