Hi themikestar,
from the values you've put there, you are aiming at quite an
interval, maybe six seconds or so ?
That transistor is capable of one tenth of an amp, maybe your
relay needs a little more ?
If you're happy that the Tr should operate that relay ok,
then you will have to reduce the resistor until the relay
operates,
then increase the cap to the interval you want.
(if the cap becomes larger than you would like, you could
'darlington-up' with another transistor, then the resistor
and cap would be different values, smaller cap, and higher
resistor.)
John