Just wanted to add- you can totally not help him if you don't want to (though he will eventually give you the Golden Shovel DIY) but, if you decide not to help him, it may still be worth talking to him because, if you collect the parts but don't turn them in, they turn into Rusted Parts the next day, which can craft that... big robot DIY thing, that IIRC, is worth a pretty penny!
I looked it up to double check and
this link here says it's 30 times. But IDK if it's "help 30 times and get the DIY the 30th" or "help 30 times and then the next time you help get the DIY"