Adding job to an ongoing print

[Robin_Goodfellow]

Hi, sometimes I need to add a part to a work in progress while it is printing. Do you think it would be a good feature to be able to add it?

[JonRaymond]

Welcome to the forum.

Unfortunately this is not possible because of how gcode is produced and read by the printer.

[pfeerick]

Well, it is, and isn’t… you can’t add to a print that is running, but if there is space on the bed left for the object you want to print, I don’t see why provision for that couldn’t be added. A more advanced form / extension of print by object?

[lkraus]

Everything is easy when someone else has to do the programming.

[pfeerick]

So? A feature request is still a feature request. Yes, you can’t add to the existing gcode, but does that mean it is not technically possible to achieve the desired end goal? Whether that feature gets implemented is entirely up to Bambu, or perhaps we might see something like in Orca Slicer one day?

[JonRaymond]

There are a couple big hurdles to jump before this could ever be a thing.

• The printer must be homed at the start of a new print job. If there are parts on already on the bed, then it can’t be homed.
• The built in printer gcode macro’s like bed leveling and also things like automatic flow calibration or the purge line can’t take into account parts that may be in the way of them completing.
• The slicer would need to somehow verify where it couldn’t print and exclude that zone from printing. It isn’t as simple as printing by object as for that the part positions are a know for the slicer and it won’t slice the plate until placement requirements are meet.

These are some big issues and I really don’t see a use case that would quantify the effort in trying to solve them?

[TurtWill]

I agree that this would not be a very useful feature, but I think it would be easier than you are saying.

@JonRaymond

The printer must be homed at the start of a new print job. If there are parts on already on the bed, then it can’t be homed.

BL printers specifically added auto step loss recovery so the printers can be homed while printing to reduce errors.

@JonRaymond

The slicer would need to somehow verify where it couldn’t print and exclude that zone from printing. It isn’t as simple as printing by object as for that the part positions are a know for the slicer and it won’t slice the plate until placement requirements are meet.

Why is it more complicated than print by object? Once the part is printed there is no need to worry about g code conflicts from printing the other part.

[JonRaymond]

@TurtWill

Once the part is printed there is no need to worry about g code conflicts from printing the other part.

It’s not the gcode that is the problem. The problem is with the carbon rod gantry and head/lidar crashing into parts already on the bed. The gantry spans the whole bed and there isn’t much room below it when the printer is printing the first layer of the “new” part.

[pfeerick]

@JonRaymond

The gantry spans the whole bed and there isn’t much room below it when the printer is printing the first layer of the “new” part.

This is why at best I think it is an extension of the print by object functionally. There is no need to home, or level the bed, as it is the continuation of the last print job. Ii.e. f you realise after starting a print that you want two more clips or something, and there is enough space on the bed to do so, I don’t see a reason (other than “it isn’t implemented yet”) for this to not be a possibility. Would I use it? Probably not, but there are always exceptions - we’re human after all. Does if matter if I would use it? No.