Board ejected from machine?

So I have a large sign I am making, in 3 carves; each about 9.5" by 41", carved from a 10.5"x48" board (3 48" 1x4's glued up).

The first board carved and cut out just fine.

But the second board, while it carved just fine, it did not handle the cutout so well.
After I changed the bit to the cutting bit, and watched it start the carve, I left the machine (and my shop) for a bit.
A few minutes later, I noticed the lack of sound from my shop - just the dust collector was running.
So I went to see what the problem was (or to check if I had lost track of time and what seemed like 5 minutes was closer to 30 and it was done).
And I came in to see the board on the floor next to the carvewright. Uncut.

I examined the board - it had a small dent on one corner, but the carving was fine.
It just had not cut anything at all with the cutting bit.
So then I rush to check the machine (and bit).
The carving bit was fine.
The machine was showing the normal job complete message, about 30 minutes faster than expected.

I shut it down, blew out the little sawdust left in the machine, pulled out the bit - my standard post carve maintenance.
I came back in to my computer, loaded up that board in designer, and deleted everything but the cut path.
Double checked and triple checked everything was set properly.

I go back out, load the physical board in the CW.
Load up the new project.
Double check and triple check everything is aligned, measuring the same size, etc.
It seems kosher.
But I have never yet had a board carved or cut right, after it had been removed from the machine.

And this was no exception.

The first pass, it traced the outline fine.
I set it to 0.24" passes, it makes three passes for the 0.72" boards I have.
The second pass seemed to be going fine.

So, I left the shop again.
I'm a stay at home dad of a 2 year old.
I can't stay in the shop to babysit my machine, no matter how much I would like to...

It finishes carving in about the expected time.
I go check on it.
And, as expected, somehow something screwed up.
There are two distinct cutouts, one shifted about 0.5" (slightly less) offset from the other.
The first, which I had watched, and then a second (the third/deepest pass) shifted so it ruined the board.

SIGH

Glue up another board.
Double check.
Triple check.
Load the original project.
Hours later, it is carved just fine.
Switching the bits...

I watch it move the board into position.
Slightly offset from where I expected it to start the cut.
But I have seen it do that before, and end up fine.
The cut motor spins.
The flex shaft hums.
The bit is spinning as fast as it can.
But the bit never descends.

The board slowly - oh so slowly, is being moved to the left of the machine (facing the keypad).
If I wasn't staring so closely, I could not have seen the movement.
If I didn't put my hand on the board, I would not have been sure.
It slowly fed the board out of the machine.
This time, I caught it, rather than it falling to the floor.
I waited a minute more, the belt still slowly advancing ... nothing, now... through the machine.
The bit never descended.
And then it ended the carve, about half an hour early.

I have NEVER experienced this before.

I tried once again to run the separate cut out only project I had created.
I noticed right away it was slightly off, and would ruin the board.
So I stopped/aborted it, and am now going to attempt to hand cut the shape.

But I am BAFFLED by the behavior.
I am attaching the MPC.

I already carved an identical but larger version of this sign - it was on 4 2x12's and came out to be 3.5' x 5' - and it carved fine.
I have carved dozens, possibly hundreds, but definitely dozens, of signs and similar projects over the years.
And I have never seen this behavior.

It just slowly, probably the smallest step it can, continued to advance the board to the left (facing the keypad), until it was ejected from the machine.

What causes this?

I have not yet run another project.
It was late, and I was already frustrated.
I will try something else tomorrow, see if I get the same odd result.

I am attaching the MPC to see if it is something I set up in there.

Just hoping for some kind of answer!

Possibly check your pressure roller switches. I seem to remember having this problem years ago and I think it was the problem. The carver doesn't realize it has reached the end of the board and 'spits' it out. I'm sure you'll get more and better info from the experienced troubleshooters shortly.
Rick H

This sounds like a tracking roller problem. That slow search for position. Are you using strips of tape on the board?
Any chance your out feed rollers/wings are lifting the board?
Head pressure not keeping the board down on the brass roller?
Bit of chunkier saw dust down in the roller cavity?

Push down on your brass roller and see if the O ring might be rubbing on the rubber belt.

Spitting the board out is a classic blind board sensor... This is caused by the right roller not becoming un compressed sending a signal to the board sensor to stand by to see the board end... No un compressed due to DUST built up on the resting plate and it spits the board out...

See pictures. I removed the 2 screws on the resting plate to blow out the dust. So a sensor check is needed... crank down on board and un crank watching the sensor data.

Masking tape will help with the tracking problem. And roller stands too so the board is supported. Even I had tracking problems before I started using masking tape.

I also make sure I have 4 inches of wood on the end so the board always stays under the rollers.. EVEN if I must tape a block on... I draw a 4 inch block on my designer art and keep everything to the left of it... And I always use place on END and leave the board longer.

AL

Well, I have another opinion.

Board being ejected means the compression roller may be stuck (dust).

Go go to search and type compression

check with options for testing sensor front and back rollers.

The board is not being measured when it ejects.

He says it ejects as it is starting the cutout and so this should not have anything to do with the board sensor or compression roller.

Assuming you have checked (and double checked) all previous troubleshooting suggestions...

1) At any time does your board leave the captivity of both compression rollers during the project run (in other words, do you have at least 3.5" 'excess' board length at BOTH ends? The 7" Rule.)

2) Is the total weight close to the maximum of 20 lbs?

3) Is the board properly supported during the entire carve and cutting operations? (Support at both ends adjusted so the board does NOT lift or DROP as it feeds through the machine.)

4) Is the plank flat? (No cups, twists, warps)