Draft Control
A control mode in which the control lever selects not the height but the target draft force. When the soil gets harder the draft resistance rises and the system raises the implement slightly to keep the load constant; this reduces engine bogging and wheel slip. It gives a clear benefit with a high-draft plough.
The system reads the force at the top link or the lower link pins mechanically or electronically and tries to hold this force at the target selected with the lever. When resistance increases the linkage rises, when it decreases it goes down. As a result the working depth is not constant, the draft load is.
- Engine speed stays more stable, and loss of fuel and time is reduced.
- Depth fluctuates by a few centimetres according to soil hardness; this is not wanted in precise work such as seeding.
- Because pure draft control can behave over-sensitively, mixed control is common in practice.
There is an important distinction regarding retrofit kits: adding electronic control does not give the tractor draft control. Draft control requires a mechanism that reads force at the linkage. The position and sensitivity modes defined on the ELF-812 must not be presented as a draft system that measures draft force; if your tractor does not have draft control, fitting a kit does not add it.
Context in which this term is used: Converting a tractor hydraulic lever to electronic control