long arms have specific frames for them---the machine is on a carriage which is on tracks- they are seldom interchangeable- a gammil machine uses a gammil frame, an HQ machine uses HQ frames- the tracks, carriages, wheels are designed to run on a specific set up- domestic/some mid-arm frames can be used by different machines- if you visit dealers, shows, workshops you can generally try out different brands/types and see what works out for you- I have a 'home made' table but a frame from the dealer for my long-arm- the tracks/bars/frame came with clamps and very good diagrams/instructions for setting up on my own table. I've been using it for 10 years and am now looking to purchase a 'real' studio frame/table for my set up.