The Singer 99K is the baby sister of the Singer 66K. Or to put it another way, the 66K is the full-size machine, and as such it fits into any vintage Singer domestic treadle base. A 99K doesn’t, and that’s why if you ever see a treadle 99, it’s a DIY job.
The bed of a 66K is just over 14.5 inches long. The bed of a 99K is a couple of inches shorter, and getting on for half and inch less front -to-back. So a 66 will fit into any ordinary “full-size” base and case, even those horrible all plastic ones sold in the late 70′s/early 80′s to “up-date” the classic portables. A 99 will only fit in either the base it was sold in, or that 99-specific Singer table called the Cadet Cabinet.
Most of the mechanicals are the same on both machines, and in practice when you switch from a 66 to a 99 there’s only two differences. You lose maybe 2 inches throat space (or what some Americans bizarrely call “harp”), and you save about 6lb in weight, which is definitely noticeable when you cart one about.
Pictured there is a 99K in front of a 66K less its needle plate and slide plate, and as you can see, the difference isn’t exactly obvious. This of course makes it interesting when a machine’s listed on Ebay, say, by somebody who doesn’t know, or professes not to know, what model it is, and all you have to go on is the usual side-on view of the machine.
OK then, can you tell which is which?
The answer is that the top one’s the 66K, and if you don’t have a picture to compare it with, the easiest way to tell is to look at the gold Singer badge. On a 66K, the top of the badge is level with what is properly called the stitch regulating thumb screw. On a 99K, the badge is well below it.
And you’d be surprised how many people don’t know that …