Can an artificer cast spells with a free hand and a shield without using an object interaction action?

Question

Suppose a level 1 artificer has a hand free and the other wielding a shield.

Can the artificer cast spells without using up their object interaction action?

For most spellcasters, a free hand is enough to cast spells, with no object interaction action required:

Material (M): [...] A spellcaster must have a hand free to access a spell's material components -- or to hold a spellcasting focus -- but it can be the same hand that he or she uses to perform somatic components.

However, the Artificer has a special requirement for their spells:

You produce your artificer spell effects through your tools. You must have a spellcasting focus – specifically thieves’ tools or some kind of artisan’s tool – in hand when you cast any spell with this Spellcasting feature.

Does this mean the artificer have to spend an object interaction action to wield the tool before he can cast a spell? Or, can the artificer access the tool as part of the spell?

Answer 1

Artificer spellcasting goes on to say:

After you gain the Infuse Item feature at 2nd level, you can also use any item bearing one of your infusions as a spellcasting focus.

Therefore, starting with the second level, if you infuse your shield or armor with Enhanced Defense, you would no longer need to wield your tools as a focus.

At first level, you still need to keep a hand on your tools, which is your only possible focus for satisfying material component requirements at that first level.