I'm playing a mechanic character who likes to scavenge and craft everything he needs. As such, I'm thinking of trying to acquire blueprints of standard stuff so my character can build exact copies of it. For instance, say I get the blueprints of an R2 unit so I can build as many R2 units as I want to, with (adv and threat results aside) all with the same stats. Has anyone attempted anything like this before? What rules would you use if you did?

The crafting rules are deliberately designed to prevent exactly that sort of thing, given that the crafting costs are invariably cheaper than purchasing the actual item.

The idea behind the crafting rules is that they're for one-of-a kind, hand-crafted items, not to allow PCs to mass-produce items, a fact that caused a fair bit of belly-aching on these forums because some folks couldn't just build replicas of various high-end items at a fraction of the cost.

That said, if all you really want to do is build exact replicas of existing items, talk to your GM and ask if you can just make a Mechanics check with a difficulty equal to the item's Rarity divided by 2. Trade-off being that you don't get to "customize" the replica item as you're no longer crafting a unique item (or droid as the case may be), but are essentially assembling a model kit, so no spending advantage or triumphs on adding extra traits as per the crafting rules.

If you were my player I'd say "as long as you pay the normal price you can say you built it instead of bought it"

House rule at the table I play at is.

Difficulty to reverse engineer is the difficulty to create a one off upgraded once,(Various Charts In Special Mod) With black Die 1-3 depending on the company size that built it. Larger companies have more proprietary tech so they get the 3 black dies. each Roll cost one of the item trying to reverse engineer. so first they have to find it. Even if Successful the item is destroyed.

Companies in the real world go to extraordinary lengths to prevent technical details of products getting into the public domain to prevent customers doing this exact thing. I imagine it would be the same if not more strictly controlled in the SW universe.

I would rule that is is extremely difficult to get full blueprints for commercial items like an R2 unit unless you took the time to strip down and reverse engineer the unit yourself. This would take long time and destroy the unit in the process.

Building an entire R2 unit from scratch would also take an extraordinarily long time unless you are using 'spare' parts from scrap R2 units that you have on hand.

This is why the RAW are for making one off items or tinkering with existing gear rather than rolling units off of a production line. That requires a factory tooled to the specific job and all of the RAW materials / manufactured components.

If it’s purely building to flip for profit then I wouldn’t even bother with the details of what and how something is built. If I was your gm i would do all of this in downtime between adventures. I would treat it as if you where negotiating to sell something. You tell me how much money you’re investing in this endeavour, then we decide on a Difficulty based on your location, the amount money you invest, tools at hand, and the amount of money you’re hoping to make back. Probably something in the order of a Hard Check, possibly with a Setback or two, even an upgrade if I was being generous.

If you succeed I’ll give you a return on your investment, starting at 10%, with an extra 5% per extra success after the first.

So I’ll give an example:

You have a few weeks, your at your groups base of operations in the corellian sector. You likely have a workshop and a few friendly merchants nearby. You have 5000 creds earned from the latest job and you think you can put together a few rifles in that time.

So it’s a fair bit of work, (Hard Check), but parts are readily available, not illegal, and tools are at hand (no setback). But that Zan snitch has been hanging around town lately, they don’t take well to competition, so I flip a Destiny Point for an upgrade.

You roll 2 Success, but also 2 Threat! So you make 15%, 750 credits for your hard work, but for some reason one of your regular parts dealers doesn’t want to talk anymore. If you had an appropriate Obligation I may increase one by a couple of points, otherwise I would give you 2 Strain to carry into the beginning of the next adventure as you worry about your merchant. If neither of those felt right I may say you damage a few tools (1 Setback on mechanics checks with your tools until you have some time to replace or fix them), or run a small encounter with some of the Zan showing up to have a little chat.

As a final option you could have a little confrontation with a loyal NPC, a Droid, or a boss, the cook, anyone. It would end with them saying “dude you need to take a break, get some rest!”