Beginner to RVing, would like an RV with a work shop.

A toyhauler would be a great choice.

If you prefer to go the class B route, an enclosed cargo trailer would probably make a suitable workshop area more easily than a travel trailer. You don't really need the double bathroom, bedroom, and kitchen facilities. You would probably need (or at least want) to add some lighting and ventilation and wiring to a cargo trailer, and maybe some heat and/or AC depending where you're intending to be, but that doesn't necessarily need to be too complicated. A small household window A/C unit set in the wall (with suitable supporting framework) would work just as effectively as a roof mounted RV AC and be a whole lot less expensive.

My first reaction to your question, before reading the other posts, immediately was "toy hauler"!

And as someone else said, a workshop in a campground will probably not be welcomed. And if you parked in a conventional mobile home park, it might not be welcome there either.

Toyhauler would probably be best bet. Be aware such a rig is probably not going to be welcome at most RV parks. Too much noise and mess (wood and especially metal shavings).

Look at the 'toyhauler' section. There are a lot of toyhaulers with a 10' to 18' long garage in them, that is large enough for your printer, small lathe, and perhaps enough weight capacity for a small mill?

Click on the upper right side of this page, and find the Jump to Forum and look for Toyhauler. Then click the arrow to actually go there.

Good luck!

Fred.