How to Send 3D Print Jobs to the Next Free Printer With the Right Filament

Which printer just finished? Which of the free ones has Red loaded? If you answer those two questions before every job, you are the one routing your print farm, and it only works while you are standing in front of it.

This post walks through how the Printago Print Queue takes that decision off you: what you set up once, what happens when a job is queued, and what to check when a job does not go anywhere.

Why picking a printer for every job stops working

With a handful of printers you can keep the fleet in your head. Somewhere past that, you can't. Every job turns into two lookups: which printers are free, and which of those has the right filament in the AMS. Finished printers sit idle until someone checks what is loaded and sends the next file. A file sent to the wrong printer comes out in the wrong color, and you print it again.

Most farms cope one of three ways:

• A whiteboard or spreadsheet of what is loaded where, which is out of date the moment someone swaps a spool.
• Sending each file from the slicer to a hand-picked printer.
• One color per printer, which leaves printers idle whenever that color has no work.

JC Print Farm hit this ceiling at 30 printers. The team was spending 3 to 4 hours a day preparing printers, loading filament and optimizing plates, and the choice in front of them was to raise prices or stop accepting new work.

How do I make print jobs go to any free printer automatically?

Printago is 3D print farm software that runs production from order to finished print. It works for a side hustle with three printers and for a facility with three hundred. Its Print Queue is where every job lands, whether you queued it by hand or it came in from a store order. Gutenbed, the matching engine behind the queue, sends each job to a printer only when all of these are true:

• the printer is online and not running a job
• it is marked clear & ready for next print
• it has a material loaded that matches the job
• it carries every printer tag the job asks for

Among the printers that qualify, it picks the one used least recently, so wear spreads across the fleet. If none qualify, the job waits.

Setup takes three steps.

Step 1: Tell Printago what filament is loaded in each printer

Matching is only as good as what Printago knows is in each slot. Bambu Lab RFID spools are read from the AMS and assigned to their slot automatically. For anything else, go to Printers, open a printer, and click a filament slot. The Printer Materials dialog opens: pick the slot under Loaded Filament and choose a material from Available Materials. Materials with a slicing profile for that printer show a ✓ Profile Configured badge.

That badge matters. On the Materials page, a Missing profiles chip under a material means one of your printer models has no slicing profile for it, and jobs in that material will never match that model until you assign one on the material's Configuration tab. See Materials for the full setup.

Step 2: Set how strict each part is about filament

On the part or SKU, set the material at the level you actually care about:

• Exact color: "Bambu PLA Basic Red" matches only printers with that color loaded.
• Any color of a material: "Bambu PLA Basic" matches any color of it.
• Generic type: "Any PLA" matches any PLA from any brand.

A bracket that ships in Red needs the exact color. An internal jig or a test print can say Any PLA. The looser the requirement, the more printers qualify, and the less time the job spends waiting. One queue then covers a mixed fleet without one printer per color.

On multi-color parts, set exact colors. Several slots set to "Any Color" of the same material can all pull from one spool.

Step 3: Print with Next Available

Go to Products → Parts, find the part and click Send to Queue. Set the quantity, confirm the material, and choose the assignment method Next Available. SKUs work the same way; see Printing SKUs.

If some jobs need a specific plate or shelf, expand Printer Tags in the same dialog and pick tags like "TexturedPEI" or "SHELF1". The job then only goes to printers that carry all of them. You add tags on the printer's page, or to several printers at once from Actions → Manage Tags on the Printers page.

What happens after a job is queued

The job appears in the Queued tab of the Print Queue. Identical copies fold into one row with a count badge, so 40 copies of a bracket are one line, not 40.

When a printer qualifies, the job moves to the In-Progress tab. Printago maps the part's materials to the printer's loaded slots, slices the file for that printer, and sends it. The row shows the printer's name, live nozzle and bed temperatures, layer progress and time remaining. A Material Mapping link on the row shows which slot each material came from.

If no printer has Red loaded, nothing is sent to the wrong one. The job sits in Queued and goes the moment someone loads Red and the printer is ready.

How does a printer get back into the pool after a print?

When a print finishes, its card on the Dashboard switches from a status indicator to a Set Ready button. Clear the plate, click Set Ready, and the printer is available again. If a matching job is waiting, it goes straight to that printer.

This is the one step that still needs a person, unless the printer runs FabMatic continuous printing or a plate changer. Printago will not start a job on a plate it has not been told is clear.

Why is my print job stuck in the queue?

Click Printer Matching on the queued job. It runs a live dry run against every printer and lists the reason each one was not chosen: missing material, missing tag, not marked ready. It checks printers that are mid-print too, so you see every real blocker at once and can fix them in any order.

The usual causes are a non-RFID spool that was never assigned in Printago, a material with no slicing profile for that printer model, or a printer nobody marked ready after its last print.

How do I reload filament without printers grabbing jobs?

Swapping spools across a row of printers while the queue is live can start a print on a half-reloaded machine. Turn off Automatic Queue Matching in the queue toolbar first. Reload, fix slot assignments, reorder the queue if you need to. Then click Match queue now to run one matching pass against the fleet as it stands.

What this changes for a print farm

You stop being the router. No more checking what is loaded where, no more choosing a printer per file. Every free printer with the right filament takes the next job, so a new printer adds output instead of adding lookups, and the same person runs more printers.

JC Print Farm went from 30 to 100 printers without raising prices or turning work away. In their words: "The smart queue is the single best feature to have and plays a vital role every day in how we operate smoothly." Read the JC Print Farm story.

Try it on your own printers

Printago has a free tier with unlimited printers. Connect your fleet, assign what is loaded, and queue a job with Next Available at printago.io.