Printing Large Objects on 3D Printer

3D printers for me are often solution in search of a problem. This is especially true in the lower price bracket where often you can spend significant amounts of time and material trying to get a perfect print. But boy, they are a lot of fun.

And when it comes to wasting time, I found getting acceptable print for objects with large footprints is really a drag. And looking up what worked for others is not as straightforward as giving a recipe since setup will depend on the printer, filament, slicer, and bunch of other small variables. I will share here what works for me 90% of the time on Ender 3 Pro with MatterHackers Build PLA and using Cura as a slicer.

When it comes to Cura, I love Standard Quality setting. While Ender 3 can perform well with the higher quality for small items, quite often printing with less than 0.2 mm extrusion is finicky and requires quite a lot of care. With 0.2 mm you won’t necessary get the best it can offer but it usually won’t cause any issues either.

Having a heated bed is pretty much mandatory for relaxed printing. I just set Build Plate Temperature to 60 °C for PLA. There is actually some room to go higher but going too wild will often make bottom layers unevenly shrink as they cool down.

Extrusion temperature depends on the filament and every manufacturer has a preferred range. For MatterHackers Build PLA that range is 180-220 °C. I set Printing Temperature smack in the middle to 205 °C. I set Printing Temperature Initial Layer a bit higher to 215 °C as it really helps with the initial adhesion.

While fan is awesome I find it cools stuff way too fast at the full speed. I just set Fan Speed to 50% and that seems to work nicely. Of course Initial Fan Speed is left at 0%.

For bigger objects I always change Build Plate Adhesion Type to use Raft. While smaller objects work just fine with Skirt, I often left large print overnight only to find them messed-up in the morning because edges started lifting off. You can also avoid this by adjusting temperature, using better surface, or some type of adhesion. However, I prefer the raft to any of those alternatives as it works even when the other settings are a bit off.

I also like to increase Initial Layer Height to 0.4 mm as it helps with removing model from the raft but that comes at a cost of slightly rougher bottom layer. I find that a worthwhile exchange. If PLA is misbehaving and I get “stringy” bottom, I might also increase Initial Layer Line Width to 150% or 200% but mostly I leave it at 100%.

From larger objects I expect a bit more of structural stability so I change Infill Pattern to Gyroid with Infill Density of 40%. I usually don’t go higher but, if I don’t need print to be sturdy or object is a bit smaller, I might go as low as 10%.

Some models might require supports and here I found Cura settings way too conservative. I always increase Support Speed to 50 mm (matching my print speed) and I lower Support Density to 10% so removal is easier. With Ender 3 Pro you can quite often go more aggressive but I found 50 mm works so well with whatever I throw at it that I don’t bother going higher.

As matter of preference I set Combing Mode to Off as I prefer “rougher” look of the final layer. I also set Z Hop When Retracted as it seems to work better with thin walls.

All these settings, while not perfect for any particular print, fail me so rarely that I have them set as a default and change them only if there is something special I am going for.