Singer 401 versus 403 (and 404)

This was something I used to wonder about - the differences between Singer 401, 403, and 404

Slant-o-Matics.  In the past year, I have acquired each of these machines and can now explain it to anyone else who is wondering.

I already covered the 404 in another post:  it is a basic, but excellent straight stitcher.  It is easy to use, practically indestructible, and fool proof.  There is nothing fancy here, just great stitching.

Singer 404 (straight stitch)

Here I will explain the difference between the 401 and 403

Singer 403 "Semi-Automatic" 

Singer 401 "Automatic"

The difference basically comes down to this.  The 403 is "semi-automatic" because it zigzags only with a cam in place (it is shown here with the "0" cam that makes the zz stitch.)  Other decorative stitches can be made by popping this cam out and substituting one of the other 22 top hat cams that are available.  This is pretty simple, and straightforward - choose your stitch pattern and pop it in.  You choose your stitch width and needle position as usual.

Singer 403 takes one cam at a time

Then you have the 401.  It is considered "automatic" because the zigzag stitch is built-in via a camstack.  This also includes a number of other fashion stitches which you arrive at by a somewhat complicated system of turning two lettered dials to get your stitch pattern.  To add to the confusion,  it also takes top hat cams to make different "combination" stitches.  (I explain that in a little more detail here.)

Singer 401 with camstack, plus takes extra cam for "combination" stitches

In all other respects, these machines are identical.  They both have horizontal (drop-in) bobbin with rotary hook, dual spool pins and dual upper tension for twin needle stitching, three needle positions, the elevated throat plate system, bobbin winder on the side, and a flip top for cam placement.

Here is a handy chart showing the 401 vs 403 stitch patterns

Now the 401 is known as the TOL (top of the line) machine for this series.  Supposedly because you had built-in stitches, this was the better machine.   

However...

If you mostly just straight stitch and zigzag - and only occasionally use any kind of decorative stitch  - then I think the 403 is actually better because it is easier to use.  With the 401 you have to dial in the combination AK3 to straight-stitch, and to zigzag you have to dial in BL + stitch width.  With the 403 you just move your stitch width lever to "S" to straight stitch, and to whatever stitch width you want for zigzag.  Easier!  And honestly, by the time you figure out which combination of dials gives you a certain decorative stitch on the 401, you could have just popped a cam into the 403 and been on your way.

While the 401 is considered by many to be the gold standard among Slant-o-Matics, just know that the stitch quality and speed are identical to the 403.  (The camstack is literally the only difference between the two.)

I love to make little videos of my machines stitching so here is a side-by-side comparison. (The 403 sounds a tad louder because it is sitting on a table while the 401 is installed in a cabinet which absorbs some of the sound.)

Singer 403

Singer 401

The stitch quality is also exactly the same, the two are indistinguishable (403 = blue/401 = red)

(NOTE:  the difference between the 500 and 503 Rocketeers is basically the same as the 401 and 403 - one has a built-in camstack and the other requires a cam to zigzag .)