Artificer>Class Features>Spellcasting>Tools Required> "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."
and in the spellcasting rules: "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."

I'm pretty sure this means that material components like those in a component pouch actually don't need to be held, you just need a free hand to access them, but more specifically i want to point out the other side of how a spellcasting focus needs to be held, and since "you can also use any item bearing one of your infusions as a spellcasting focus." this means that infused item needs to be held, and not just accessed with a free hand.

What does it mean to "hold" your spellcasting focus?
(I assume this means you are holding it with your hand, and not your feet or something.)
With infused items like the Enhanced Weapon, it's pretty obviously "held",
but what about Mind Sharpener robes? Can I grab my robes with my hand while I'm still wearing them and have it count as "holding" them?
What about the Goggles of Night? Can I grab my goggles without taking them off my head and be "holding" them?
What about the Helm of Awareness? Can I grab a horn on my helm while the helm is on my head and be "holding" it?

You'd probably need to work that out with your DM. There's a magic item for wizards, the hat of wizardry, which can be used as a spellcasting focus; my DM let wearing it count as holding it (otherwise you'd need to grab it and take it off and wave it or something, which is awkward.)

Love the username/avatar btw.

The Artificer Spellcasting feature is also specifically restrictive on this:

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 (meaning the spell has an ‘M’ component when you cast it).

With this language, I’d be a “no” for armor / robes / boots / goggles, but ok with gloves / gauntlets / shield / amulet / ring, as well as other amusing infused items like a bag of holding.

As specific beats general, I'd argue that the rule of using an infused item as a focus trumps the general class rule for artisan tool foci.  As such any infused item will work provided you had a free hand; You can touch your goggles, grasp your robe etc.

What I would say is that subclass features like Alchemical savant wouldn't trigger as they need to be through a specific tool.

While this sounds odd, imagine being put in jail.  You might have your infused boots with you but your tools taken away.  Infused items are a fun way to sneak in an unsuspecting focus.

I would agree that using an infused item is a specific rule overriding the general rule for spell focus use. So go ahead and use those Goggles by touching them. No need to remove and wave around.

Quote from banksmj >>

The Artificer Spellcasting feature is also specifically restrictive on this:

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 (meaning the spell has an ‘M’ component when you cast it).

With this language, I’d be a “no” for armor / robes / boots / goggles, but ok with gloves / gauntlets / shield / amulet / ring, as well as other amusing infused items like a bag of holding.

Don't see where the confusion is. "in hand when you cast any spell". If it aint in your hand, you aren't casting anything. So if you have to grab something magical, then you best do that. The easiest solution will be to simply create a infused ring, then you'll be fine.

Quote from banksmj >>

The Artificer Spellcasting feature is also specifically restrictive on this:

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 (meaning the spell has an ‘M’ component when you cast it).

With this language, I’d be a “no” for armor / robes / boots / goggles, but ok with gloves / gauntlets / shield / amulet / ring, as well as other amusing infused items like a bag of holding.

 I don’t know how is “specifically restrictive” as it tells you what you need to do at 1st level, then provides a different option for spellcasting at 2nd level. 

Spellcasting

You have studied the workings of magic and how to channel it through objects. As a result, you have gained the ability to cast spells. To observers, you don’t appear to be casting spells in a conventional way; you look as if you’re producing wonders using mundane items or outlandish inventions.

Tools Required

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 (meaning the spell has an ‘M’ component when you cast it). You must be proficient with the tool to use it in this way. See chapter 5, “Equipment,” in the Player’s Handbook for descriptions of these tools.

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.

Now if you infused a shield with a defensive infusion and gave it to the Barbarian then I don’t think you can use that. But as long as you have the infused item on you it should work. It specifically says you are channeling your spells through objects. So if you are wearing Goggles of Night and cast burning hands you could go all X-Men Cyclops, touch the side of the goggles, and flames shoot out. 

But artificer does seem to be oddly worded sometimes. 

Quote from ThriKreenWarrior >>

Quote from banksmj >>

The Artificer Spellcasting feature is also specifically restrictive on this:

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 (meaning the spell has an ‘M’ component when you cast it).

With this language, I’d be a “no” for armor / robes / boots / goggles, but ok with gloves / gauntlets / shield / amulet / ring, as well as other amusing infused items like a bag of holding.

 I don’t know how is “specifically restrictive” as it tells you what you need to do at 1st level, then provides a different option for spellcasting at 2nd level. 

 

Spellcasting

You have studied the workings of magic and how to channel it through objects. As a result, you have gained the ability to cast spells. To observers, you don’t appear to be casting spells in a conventional way; you look as if you’re producing wonders using mundane items or outlandish inventions.

Tools Required

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 (meaning the spell has an ‘M’ component when you cast it). You must be proficient with the tool to use it in this way. See chapter 5, “Equipment,” in the Player’s Handbook for descriptions of these tools.

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.

Bolded and underlined by me for emphasis  

 

Now if you infused a shield with a defensive infusion and gave it to the Barbarian then I don’t think you can use that. But as long as you have the infused item on you it should work. It specifically says you are channeling your spells through objects. So if you are wearing Goggles of Night and cast burning hands you could go all X-Men Cyclops, touch the side of the goggles, and flames shoot out. 

But artificer does seem to be oddly worded sometimes. 

Agreed, as long as you are physically touching the item of which has an infusions of yours, you can cast a spell. The only restriction is that, ALL spells the Artificer casts requires a spell focus, making ALL spells have the M requirement. Which is 100% GOOD, because that means you can cast everything through FULL HANDS and do not require having a free hand to do so.

Quote from Homnommunch >>

Quote from ThriKreenWarrior >>

Quote from banksmj >>

The Artificer Spellcasting feature is also specifically restrictive on this:

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 (meaning the spell has an ‘M’ component when you cast it).

With this language, I’d be a “no” for armor / robes / boots / goggles, but ok with gloves / gauntlets / shield / amulet / ring, as well as other amusing infused items like a bag of holding.

 I don’t know how is “specifically restrictive” as it tells you what you need to do at 1st level, then provides a different option for spellcasting at 2nd level. 

 

Spellcasting

You have studied the workings of magic and how to channel it through objects. As a result, you have gained the ability to cast spells. To observers, you don’t appear to be casting spells in a conventional way; you look as if you’re producing wonders using mundane items or outlandish inventions.

Tools Required

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 (meaning the spell has an ‘M’ component when you cast it). You must be proficient with the tool to use it in this way. See chapter 5, “Equipment,” in the Player’s Handbook for descriptions of these tools.

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.

Bolded and underlined by me for emphasis  

 

Now if you infused a shield with a defensive infusion and gave it to the Barbarian then I don’t think you can use that. But as long as you have the infused item on you it should work. It specifically says you are channeling your spells through objects. So if you are wearing Goggles of Night and cast burning hands you could go all X-Men Cyclops, touch the side of the goggles, and flames shoot out. 

But artificer does seem to be oddly worded sometimes. 

 

Agreed, as long as you are physically touching the item of which has an infusions of yours, you can cast a spell. The only restriction is that, ALL spells the Artificer casts requires a spell focus, making ALL spells have the M requirement. Which is 100% GOOD, because that means you can cast everything through FULL HANDS and do not require having a free hand to do so.

 That’s one of the things I like about artificers, you can flavor them so many ways since they cast through an object or infused item. You. An have an artillerist with their arcane firearm like the Fifth Element ZF1. Repeat mode (magic missile), flame thrower (burning hands) etc. plenty of options for flavor being able to use infused items for your focus