For a simple part like that it may work. But PLA isn't a great material for this. FDM in general isn't great. There is a good chance the PLA won't burn out completely, and you'll end up w/ bad spots on the cast part. You generally want to use a resin printer w/ casting resin. They make 'wax' resins where you can easily add wax and post process the part w/ wax casting tools. But the casting resin is like 5x the cost of regular resin.
BUT casting is super expensive to get in to. You'll pretty much need both a kiln and a melting furnace. Both can be made if you like DIY.
I've been planning on getting in to casting for years (to make metal parts for printer / CNC mostly lol). I was going to use PLA for lost casting, but after researching I thought going resin is worth the added cost. I'm going to buy a melting furnace this week. Probably this one
https://www.amazon.ca/Masters-Propane-Furnace-Crucible-Smelting/dp/B073DRQY98. Ratuken rebates coming in 3 days and I have enough from my Dell purchases to pay for 95% of it. I got a boat load of cans saved up so I can start melting asap.
Kilns tho are expensive. You are looking @ $1500ish for a 120V tabletop one in Canada. You can get used 240V massive commerial kilns on Kijiji for maybe $500. But I don't have a 240V 30A+ circuit. So I'll be making my own. Rip apart a toaster for the heating coil. Fire bricks are pretty cheap. Already have a kiln thermistor and PID controller, both were cheap'ish. Then just need a container and something else to fill the gaps. Tons of youtube tutorials out there on making one.
And then you really need a vacuum machine to remove air from the plaster mix, the poured mold, and generally when pouring the metal as well to insure no bubbles. Cheap ones you are looking $250 and they go up to $2k.
Plus safetly equipment and tools. Even with DIYing a bunch of stuff, i expect everything to cost close to $2k.
