  We present observations and analysis of 18 stripped-envelope supernovae
observed during 2013 -- 2018. This sample consists of 5 H/He-rich SNe, 6
H-poor/He-rich SNe, 3 narrow lined SNe Ic and 4 broad lined SNe Ic. The peak
luminosity and characteristic time-scales of the bolometric light curves are
calculated, and the light curves modelled to derive 56Ni and ejecta masses (MNi
and Mej). Additionally, the temperature evolution and spectral line
velocity-curves of each SN are examined. Analysis of the [O I] line in the
nebular phase of eight SNe suggests their progenitors had initial masses $<20$
Msun. The bolometric light curve properties are examined in combination with
those of other SE events from the literature. The resulting dataset gives the
Mej distribution for 80 SE-SNe, the largest such sample in the literature to
date, and shows that SNe Ib have the lowest median Mej, followed by narrow
lined SNe Ic, H/He-rich SNe, broad lined SNe Ic, and finally gamma-ray burst
SNe. SNe Ic-6/7 show the largest spread of Mej, ranging from $\sim 1.2 - 11$
Msun, considerably greater than any other subtype. For all SE-SNe
$<$Mej$>=2.8\pm{1.5}$ Msun which further strengthens the evidence that SE-SNe
arise from low mass progenitors which are typically $<5$ Msun at the time of
explosion, again suggesting Mzams $<25$ Msun. The low $<$Mej$>$ and lack of
clear bimodality in the distribution implies $<30$ Msun progenitors and that
envelope stripping via binary interaction is the dominant evolutionary pathway
of these SNe.
