I understood that the three manufacturers were Asin Seki (a Toyota group company), Juki and Babylock. Various brands and companies own patents on various bits, but the three manufacturers have licences to produce machines for them. Each brand/company specifies what they want, puts it out to tender, and buys in from the company who offer what the brand considers best fits their market. Thus you only see the free arm on the Huskylocks because they tend to be expensive to produce, and other brands cannot see their customers wanting them enough to pay that sort of price for them... You only see that marvelous totally opening front on Frister & Rossman, because they own the patent and won't let it out to other brands... Same with the air jet threading...
This is why, even though all the machines are made in the same three factories, and many (especially in the lower price brackets) share component parts, you never see all the fantastic features you REALLY like on the same machine!
The Toyota brand machines and the Huskylocks are made by the same folk, share a sturdiness and general reliability, but no component parts are the same! AAARRGGHH! Best thing to do is just go round and TRY as many as you can within your price bracket, and see which does the most of what you really want. I came to the conclusion that the air jet threading was for wimps ( ;P ), and I much preferred the free arm, as I could learn to thread a serger very quickly, but there were always going to be places where the free arm would make life so much easier it was worth the extra dosh! I'd dearly love that Frister & Rossman fold back opening: having had one to borrow for a week, I can tell you that it makes cleaning and oiling a breeze!
What I needed in a serger was:
Relative ease of threading
4 threads good rolled hems with easy change-over easy cleaning Something that would slide through 3 layers of Polartec 300 as easily as silk, and would roll a silk chiffon hem with the same panache would withstand the high volume I doIt came down to two: the Bernina and the Huskylock. Huskylock won on the free arm: the Bernie was the same price without it! The only advantage the bernie had over the Huskylock was that it was quieter!
Now, I have had a few problems with my Huskylock getting stiff on me this last year... After some debate and experimentation, Wilf, my sewing machine wizard, has come to the conclusion that, because I use it more than your average domestic user (who is surprised to hear they? No-one? ;D ), and tend to do long runs on awkward fabrics at high speed, I need to:
1 Clean and oil every couple of days/end of every project, whichever comes first 2 Use industrial machine oil, which, being designed for faster machines, is a little more viscous and won't be soaked up and used up quite so quickly as regular sewing machine oil (which is just fine for 90% of domestic users, and all hand crank and treadle machines)If, after a few weeks of this, I still have problems, we are going to Have Words With Husqvarna to see what they recommend...
I am on the cusp of needing commercial machines, but really do not have either the room for them or the right setting, as they are noisy, so not what I want in an upstairs bedroom in a terraced house!
My very strong recommendation would be to take all the different types of fabric you sew regularly with you, test all the functions you want to use on these fabrics (but remember, some things are impossible, like button holes, and rolled hems on Polartec 300!), and see on which machine you can do what you want to most easily: aim for that one! It might be a second hand Toyota, it might be a Babylock Evolve... In which case, Start Saving NOW!
And have fun trying!