Sorry, I was changing the values of the resistors as i was tinkering, changing the voltage then changing the LED resistors appropriately. Alsh the cap and resistor to change the timing. I know my Tinkercad drawing doesn't match the design I was copying. After I moved the resistor as bertus pointed out, the circuit worked correctly.

I tried to build it on a breadboard but the LED just stays on. I think my 555 is bad.
Anyway thanks for all the help and interest. Just trying to learn.

Post pictures of the breadboard layout, you might have it wired wrong.

 

OK, I fiddled with it some more and now it's working. I did both astable and monostable. Changing the electrolytic cap to 10 uF and the resistor between pins 6 & 7 made it flash at the about 1 second interval I was looking for.

Not sure what was wrong, I think it was wired correctly but probably something loose on the breadboard.

I did discover a couple things:

Putting a voltmeter probe to pin 3 made it momentarily dim the LED on the monostable circuit then back on.
also,
Removing the jumper between pins 2 and 6 made the astable circuit act like the monostable circuit

I'd send pics of the breadboard but it's a mess. I have several other circuits on the board. It would cause more questions than it would answer. I need more breadboards!

Thanks again to everyone who responded.

 

Hello,

If you want to have some more fun with the 555, read the attached forrest mims booklet.

Bertus

 

Putting a voltmeter probe to pin 3 made it momentarily dim the LED on the monostable circuit then back on.

What kind of voltmeter are you using?

Removing the jumper between pins 2 and 6 made the astable circuit act like the monostable circuit

Can you explain why?

 

It is an inexpensive Digital multimeter (Chinese no doubt) Astro AI DT132A.

Aaah, a test! OK I think pin 6 pulls the voltage on pin 2 down triggering the cycle?

But why does the voltage probe to the output pin trigger the cycle?

 

It is an inexpensive Digital multimeter (Chinese no doubt) Astro AI DT132A.

The input resistance of a DVM shouldn't be high enough to load the output of a bipolar 555.

Aaah, a test! OK I think pin 6 pulls the voltage on pin 2 down triggering the cycle?

From TI's datasheet:

Pins 2 and 6 are inputs, they can't pull anything down.

But why does the voltage probe to the output pin trigger the cycle?

It shouldn't.