Can I change layer height on the fly ?

Sometimes it's quicker to stop and start again.

 

No and Yes.

No, there's no way the printer can recalculate the model print at a new layer height; that's not its job.
Yes but it'll be tricky. If you reslice it at a different layer height and work out which layer you want to switch over to the new layer height, you can replace rewrite the file that the printer is printing from. Printing from a network share, the file is buffered a little a time by Octoprint. So, let's say you're on layer 50. You figure layer 55 would be the right place to change. You use Notepad++ or some similar tool to edit the file that's being printed and you overwrite from layer 55 onward with the end of the gcode from an alternate slice. It would not be simple, but it would be doable if you think it all through carefully.

 

People often forget one can increase print speed by increasing extrusion width.

However one needs to thin through all the consequences.

If you go from 0.5mm extrusion width to 0.75mm that's 50% more plastic going out at each pass.

For example,

- manually reduce perimeters from 3 to 2;

- infill will automatically have fewer strands at the same percentage;

So the nozzle travels a lot less to complete the job aka faster!

 

If you are using Simplify, create a new process and change whatever you need in the new process at your new starting point. You can change infill, layer height, etc in the new process.

 

On the big box, it isn't much easier to swap anything, As the hotend isn't actually in the titan, but rather the hotend is connected to the titan using a bowden coupling and ptfe tube that goes through the X-Carriage...

 

That's the case for a Titan in its intended guise but it appears that the BigBox Hybrid is still using the X carriage to mount the hotend assemblies. Also, the second extruder is mounted on the back of the box. It is a shame that this is not being used as intended but I assume that @Greg Holloway is working on this for a non-hybrid dual some time in the future. I will be looking at a design once I complete my BB and the project I bought it for unless Richard Horne beats me to it.