[JKAVS]

Could someone explain the difference between DFU and OFU ball nuts? DFU means double nuts but OFU means off set double nut. What does the "off set" mean here?

[dustin1706]

Could someone explain the difference between DFU and OFU ball nuts? DFU means double nuts but OFU means off set double nut. What does the "off set" mean here?

The specific design can vary a bit by manufacturer, but basically it's just two ways of accomplishing the anti-backlash. The DFU uses a spring or spacer of some sort to apply preload. If your machine force overcomes this spring/spacer compressive strength, you will end up with backlash. The OFU is actually a continuous, one-piece nut, but has a small offset in the threads halfway through that applies the preload by providing two points of contact.

The advantage of the OFU is that it's a solid piece that can withstand more force, so it's meant for heavy duty applications. The downside is that it requires a precision fit to the ballscrew (get them from the same manufacturer) and is not adjustable. Unless you have a specific use case for OFU, go with a DFU style nut.