Comparator suggestion.
Hi murdell,
Now I understand your dilemma!
Your project is a good test for study in electronics.
Using a LM741op-amp, for a comparator is not very good. It has a linear output circuit, not designed for 'switching' style output.
It might work, but will be unpredictable.
Much better to use a real comparator, say LM393, dual, low-power, comparator. It's available from Jaycar and Altronic for less that $2.
Have a look at spec sheet. Hope you understand the terms used.
http://www.national.com/mpf/LM/LM393.html#Overview
LM393 will work OK, if not required to drive much external load on the output pin. It's not guaranteed to 'sink' more than 6 milliamps!
A real 555 can 'sink' 200 milliamps under some conditions.
Also you will need to put a 'pull-up' resistor on the'output' pin, since LM 393 output pins are 'open-collector'. See the schematic diagram.
Good luck, and ask again if you need more help.