I started plugging it into the simulator and realized right away a problem.
If M1 and M2 are the motor contactors, then there is nothing to retain them once the N.O.? start button is pushed and released?.
Max.

Yes, I pointed out to him in PM that he needs to latch past the start button with M1 & M2 N.O. contacts in parallel. He's fixed it already.

 

He hasn't updated his print!
Max.

 

Yes, I apologize. I just forwarded the same message to everyone. M1, c3 on motor 1 and m2/c3 on motor 2 (aka the holding contacts) need to be extended to prior to the start button to work, credit to strantor.

 

I checked it briefly with the simulator and it steps through the four conditions, except when it goes to repeat, both motor turn on off, I did not get much time tonight to dig deeper, hopefully tomorrow I will see if any thing pops up.
It could also be partly due to the faster acting PLC simulation, but if this bug is eliminated on the PLC then it may make it a bit more bullet proof.
Did you update your print?
When it cycled through correctly for one four step cycle , I did not see CR3 pick up at all!
Max.

 

When it cycled through correctly for one four step cycle , I did not see CR3 pick up at all!
Max.

Set a trap bit for it. In a plc it's only going to be high for one cycle.

 

Looks good to me.

The only question I have is possible timing. On the first press if M is large and slow. Could cr pull in M2 before M/nc breaks?
I take that back. Cr is delayed by pull in time of M.

The instruction were misunderstood by me.
I noticed the need to be able to stop motors between sequences. What I did not know is that it was required to do so.

That takes away strantors requirement for timing.

I don't think I've posted a spoiler. If I have let me know and I'll delete.

The timing issue I see is with cr3; as mentioned above, in a plc it will only be high for onc cycle, and it will work. With physical relays, the brief period during which it is on may not be enough time for m1 and m2 to close and latch, since they are bigger and slower. I don't know if this real world stuff matters for the exercises. OP, are you expected to build a work circuit and demonstrate?

 

I made a couple of changes to seal CR3, worked like a charm on the simulator.
I did not see it originally as it was only on for one scan.
With discrete relays timing, this may, or may not be a problem.
Max.

 

The timing issue I see is with cr3; as mentioned above, in a plc it will only be high for onc cycle, and it will work. With physical relays, the brief period during which it is on may not be enough time for m1 and m2 to close and latch, since they are bigger and slower. I don't know if this real world stuff matters for the exercises. OP, are you expected to build a work circuit and demonstrate?

Yup, I gotta build it. It will be built tomorrow at 8AM, will post results and pictures.

 

Made a mistake whilst wiring it, so it ended loudly. Will show results of actual (correctly) wired circuit on Monday.

 

Crimsonblood?? Is that as in Sweet Home Alabama?
UT long, long, long, ago and further away