Can you make juice in a blender? Absolutely ... you'll need to strain it through a nut milk bag or fine mesh sieve to take out the pulp. Juicers do this bit for you, often using high speeds ...

you may still need to use a mesh strainer for a completely pulp- and seed-free OJ. A counter top press is also an effective juicer, and while it's a bit more of an investment, you can juice a lot ...