You definitely need a ruler base for your longarm. Here is a great blog from APQS describing it.
http://www.apqs.com/blog/2014/07/22/...hen-you-quilt/
You can can probably find one on line to fit your machine, it looks like they are pretty universal for APQS
https://shop.apqs.com/Hartley-Base-E...ter_p_115.html
or if you are handy and have a good place to cut thick plexi you may be able to fabricate one on your own.
Also APQS appears to recommend using the template foot when doing ruler work.