After an 18-month hiatus, NASA's Curiosity resumed drilling and sampling rocks in May using a new technique known as percussive drilling, which allows Curiosity to keep its drill feed
According to a (https://gizmodo.com/nasa-s-curiosity-rover-is-able-to-drill-holes-into-rock-1826271498) Gizmodo report, first electrical issues plagued the drill's hammering mechanism and then the vehicle's drill feed
malfunctioned in December that year.
Excessive rotational speed or drill feed
will cause the cutting forces acting upon the drill to be greater than they should be.
When rotated at a high speed and pressed with high axial force into sheet metal or thin walled tube, generated heat softens the metal and lets the drill feed
forward, produce a hole, and form a bushing from the displaced material.
In drilling, this problem can be caused by using the wrong type of drill or a dull or incorrectly sharpened drill, or by an excessively light or slow drill feed
, among other factors.
Accurate drilling is a combination of minimised in-hole deflection and careful alignment of the drill feed
as dictated by pre-planned blast patterns.
The hydraulic system for operating drill feed
is self-contained and includes an oil reservoir.
Difficulties were experienced in holding the vehicle steady at the ice face and controlling the drill feed
To improve visibility from the operator station, the drill feed
has been mounted sideways on the boom.
Changing from AISI/SAE low carbon mild steel at 20,000 psi tensile to stainless in the 70,000 to 120,000 psi range, alloy steels such as 4130 with 70,000 to 200,000 psi, or titanium alloys with 130,000 to 190,000 psi tensile, drill feed
thrust increases almost directly by this tensile difference.