Do you have a recommended vacuum pump?
We recommend a vacuum pump that creates at least 3 CFM of vacuum for our vacuum chucks. There's a couple options available for these pumps. The first option is a low-priced pump such as the Robinair pump found on Amazon here
I have a couple of these pumps and occasionally there is some oil smoke that comes out of the breather. I have not experienced a situation where this has any effect on what I'm turning. However, I do know that there are reviews out there were people are very dissatisfied with these pumps because of issues with oil. The thing is they don't cost very much and that's why people use them.
The second option is a vain pump that's completely dry such as a Gast pump. These pumps can be quite expensive but they're very reliable and you will have no issues with oil ever.
Personally, I just position the Robinair pump behind my lathe so it's well away from the work piece and I've yet to have a problem. Another thing to keep in mind is if you purchase it on Amazon and it does turn out to be an issue you can always return it.
Hope that answers your question, if not be sure to let me know.
Thank you for your interest in our wood turning tools and accessories, I really appreciate it.