1.3mm might be very prevalent in the metric world; but, can be hard to come by in the United States.
So, I have made an effort to make it as easy as possible for you to locate and buy a 1.3mm Hex Driver.
I wa able to find one at Hobby Hanger in Chantilly, VA. While they do not sell online, you can call them to purchase the MIP9013 that I talk about here.
Perhaps the easiest way to order the 1.3mm driver is to go straight to the source.
Moore's Ideal Products (MIP), located in Covina, California, is a company serving the hobby market. They make a high quality 1.3mm hex driver (Model #9013) that can be purchased in hobby stores or on their website. The cost is $15.00. Here is the product page MIP9013.
MIP tools have the extra benefit of being color coded. I have tested this driver on my own cube3 and it works very well. At first glance, it might seem a bit expensive for a single application. But, it's a lot less hassle to fix the Cube in the field than other options.
Besides, getting to know the MIP site has other benefits.
It was not only great to find a good source for a very rare tool; but, it promises to be a great source for accessories that we can use to enhance our own 3D printing projects. Most of the tools and accessories I have found most useful, have come from a hobby shop or a hobby site. And, if the hex wrench I purchased is any barometer, they deliver first class product. Now that I've seen all they have to offer, I'm thinking of using some of the gear, clutch or differential parts in one of our immersion classes. Sounds like fun! :)
UPDATE - Harbor Freight Driver Set
Eric Albert alerted me to a set of drivers from Harbor Freight that includes a 1.3 hex bit. The price is $6.99.
This is equally good news as Harbor Freight has many local stores.