Nearly crashed my denford triac machine and not sure what went wrong, help please?

[JAZZCNC]

Don't worry about not understanding the Steps thing as you don't need to understand to work the machine. All you need to check is that the machine returns to Zero. If it doesn't then we'll worry about teaching you all about Steps per etc.

Regards Knocking the Shuttle then I can't see that being the cause unless you accidentally caught it before pressing cycle start and set one or both the Axis DRO's so a number other than Zero was entered into the DRO's. Then the Zero location would be differant to where you thought it was.
This is the only explination I can think of because if you was already deep into the material and the DRO changed from Zero to say +/- 5 then the machine would travel side ways.

Try this in air to see what I mean. Zero the DRO for X & Y then type 10 directly into either DRO. Then type G0 X0 or Y0 depending on which you changed into MDI input line and you'll see it moves sideways for that axis.!!