Design Internship payment questions

Hello,
I just picked up some work designing (first design job) some products for a small company making some truck accessories. I’m getting hired on as an Intern but I think I’m doing a little more than “intern” work. That’s absolutely fine by me since I can’t wait to get my hands dirty but the employer wants to pay me via piecemeal or when I reach certain “milestones” as he put it. I guess more like freelance. Anyway I haven’t the slightest clue how to charge for something like that. Like how much would a person charge for a Solidworks rendering, or a CAD layout that’s being sent to a CNC machine or laser cutter? Or even hand sketches or photoshop renderings. I know this is all a little vague but any advice would help greatly. Thanks!

So is he expecting you to give him an invoice which to pay? Or did you agree to any up front terms on your time?

I would say your best and most easily understood bet would be to put a dollar amount on your time, keep accurate track of your hours, and put that down as how much he owes you.

Whether or not he’ll pay is another thing.

We only met for about an hour, he basically showed me what he had planned for his next projects. Salary, other than paying piecemeal didn’t really come up. I don’t want to give him sticker shock, but at the same time I really don’t want to work for below minimum wage either I guess. Then again with so many unpaid internships maybe I’m lucky I’m getting paid at all. He’s drawing up some paperwork and we meet again in 2 weeks. I guess I’ll keep working with what he gave me and see what happens.