Maker" and "Make," are now synonymous with gadget hacking and DIY projects, then what better DIY project to pursue than the last option, right?)
Research, research, research. Dozens of companies use "Maker" as their mark (and let's not forget "Maker's Mark"). What matters is whether your name is likely to confuse consumers of the 3D printing company ( or any other similar-named company within your industry). So, you will need to familiarize yourself with standards of "likelihood of confusion." Then, you need to do a trademark search. Fortunately, we're here to help with a handy video explanation of how to do that. (By the way, besides searching the U.S. Patent and Trademark Office (USPTO), you can also search at Trademarkia.) When searching, search within in connection with your goods or services using the single term "maker," and then again using the compound of "maker" plus whatever second term you are planning on using preceding or following "maker."
Feel good? Register. If you feel confident about moving ahead, you may want to federally register the trademark as that creates a presumptive right to your use. You can learn registrations basics and also how to deal with any objections after you submit your application to the USPTO.