@vicious1 have you ever seen this? I had a cut running for 4 hrs and it was on the 10th pass, and it just did it again. I have everything at default, I know I’m running faster than normal, but there are no burn marks, very very little chatter, and it wasn’t on a knot in the wood.
It just suddenly stops pushing through, I’m pinging you because this time it was with a brand new 1/4" upcut spiral with 2 flutes.
What control board and what firmware?
A single flute is still better option in wood for our ROM range. What depth of cut, what feedrate, how big is your machine, why type of wood are you cutting?
Have you made any edits to the firmware?
May I see a picture of your build please.
This is not a common issue, we are looking for something out of the ordinary, there are obviously thousands of possibilities so it is best if we cover everything.
Is it always the same axis?
it is always the same axis, the x axis
Did you find a loose connection previously, did you tape up all your connections like JJ posted about?
Is the stepper noticeably super hot?
Also I have checked the wires and resoldered the connections to the extension. The only loose point that could happen is at the jackpot board, it’s snug everytime this happens so I am doubting it’s the issue. I did remove the connector on the board though and plugged the stepper directly to the board instead because the connections didn’t match with what I had and it fit snug
That’s 42.3333 mm/s, or 2540 mm/min…
for those of us who use freedom units everywhere except 3D printing and CNC… 
Is your core wobbly at all? All of the bearings making good contact?
If you block up the beam and with the LR4 turned off can you move the core side to side smoothly?
Wires secure in the beam, none hanging down where they can get in the way of the core bearings on the EMT?
The thing here is if you were actually pushing to hard you would skip steps not stop.
Stopping happens only if your drivers overheat, or you get a disconnection, or you mess with your board wifi connection.
As for your speeds. They are not right.
1-2 diameters in depth is standard. You are cutting at 1/2d at 42mm/s. You have considerably more power at 1d at 21mm’s, and possibly even more at 2d at 10.5mm/s. The issue here is you are using a two flute in wood at high RPM with a large diameter, you will never get the wood out of the way and recut it. So for CAm go to 6mmDOC at 18mm/s start your cut and see how low you can go with your RPM, Faster is not better.
That said, this is most likely not your issue.
You can put a fan on your stepper drivers but you have not answered anything about your board or firmware, I would love to see pictures about that. P.S. Do not refresh the UI during cutting. Start your cut and leave the controls alone. (The newest firmware is going to address a lot of this but there are still bugs).
The only other far fetched issue could be the power connection got beat up and is loose. Might want to hit those with your soldering iron to make sure the Green power port is making good contact with the jackpot. We have had at least two now with the terminals overtightened and popped the solder.
Here are some pics of the machine and board
I tried my feed at 2540 mm/min with the single flute 1/4 and it seems to cut better even at 6mm doc.
I have another oak board I’m going to test tomorrow and I’ll have the infrared thermometer out there to check temps while it runs.
I also got the fan from you so I may add that after if it fails again.
I have the settings matching the documentation, it’s in AP mode, but good to know about the refresh, I will make sure to put the tablet away after starting it
That’s interesting, I will for sure check that, I didn’t even contemplate that but it very well could be
#1 issue is you have covered your wifi antenna with wires. Huge No-No.
The vast majority of us use mm/s since you can visualize about how far that is 12mm/s (1/2" per second) is something you can visualize pretty accurately. 2540mm is pretty hard to guess at and trying to figure one minute is even harder. That said…anytime you use those units we all have to go google the conversion. Not a huge deal but it will speed up the responses if we don’t have to do so much work.
That vac hose needs to be attached to the core. Hanging is killing your accuracy. Even better is to attach it to the core, and run it to a side plate before you go to the hanging part.
These units are the only that make sense in engineering things 
True, it’s harder to convert fast, but it’s way more accurate for slow milling like metals, or operations like homing, probing… at least that’s why I prefer to use it
