Saline, Saline over the Seven C-Cams.
Ahoy!
These waters you tread are dangerous indeed. The sirens are a'calling, and you may find yourself lost before you see a shore again.
We'll be a' talkin' about the Kenmore cams.
/me clears throat
For the Kenmore Experiment, I wanted to help set you all up with what you'll be seeing me work with that isn't really in many modern sewing machines.
PATTERN CAMS!
These little beauties are not really seen with modern machines any more for a number of reasons. One of which being that they just build them all in now for simple mechanical machines, or can program them into the onboard computer and never bother yourself with cams again.
Pattern Cams are actually a fancy name for the mechanic that helps make your stitch shape. Sort of a mechanical instruction for your machine for where the needle is supposed to go, and how the machine should move the fabric.
To me this is probably my favorite part about mechanical sewing machines, because it is fairly reminiscent to some of the oldest computing machines. The precursor to the modern binary computer. (which took its queue from Jacquard Silk, and the binary nature of their pattern cards). The cams in these mid 20th century Kenmores are the instructions for the machine.
Just like in old computing, different models took their own special ways of getting their instructions. We see the same in the Kenmore family being that there are cams ranging from A through G style. These cams often included two layers of information. 1st layer being the needle position upon a stitch, the second layer being feed dog direction between stitches.
Changing up the position of the needle in the stitch allows for the zig zag, moving left and right based upon a bump or notch on the needle layer of the cam. The motion of the feed dog, allows the change of the position of the fabric for when the needle inserts into the fabric for the stitch. This is how you get your stretch stitches and your back stitches, and get them consistently.
Any pattern that is "non-linear" mathematically requires a two level or greater pattern cam. In this case "non-linear" aligns with the mathematical approach to linearity. If you plot the sewing direction as the X, and the needle position as the Y, you cannot have more than one Y for any single X and be linear. So a zig-zag is linear, but the Grecian wave is not.
From what I can tell: Layer 1, the larger the radius the farther right, the smaller the radius the farther left. Layer 2, the larger the radius the farther back in the stitch, sort of a stitch length multiplier in reverse. And if it stays back, it stitches in reverse. This is where the pattern length adjuster knob comes in handy. This helps adjust that multiplier with the stitch length. Which means for a 1 layer cam, not having that second layer it is a radius of "0" which means just stitch forward.
With the machines here in my Kenmore Experiment all of them use the C-cams, which are wider cams that have a greater diameter than some of their other cams, but have the top-hat shape. This greater diameter allows for more detailed instruction to be conveyed through the mechanical linkages. As there is more space between the changes in the edges of the cam, and thus allows one to adjust the width and length of the stitch by adjusting the timing of how fast the cam turns in comparison to the feed dogs, as well as a multiplier for the position of the needle to control the width. This is how we get the details of the Tree, and the Swan when it was previously not available in another set.
For C-Cams there are 22 single layer cams (0-19, 53, and 20 is a stretch stitch modifier) 29 double layer cams (21-36, 38-45, 50, 56, 121) and 6 three layer cams (83-88)
In very general if you are trying to figure out which Cam you have you may use this link. Other quick indicators are:
A-Cam: Deep Red tophat style cam
B-Cam: Black non-circular tophat cams
C-Cam: Mint Green, Rich Green, Rich Orange (1 layer), Muted Green, Muted Orange (one layer), or White/Cream top hat cam.
D-Cam: Pink/Cream top-hat cam that are roughly the same shape as the A-Cams
E-Cam: Bi-layered open center cams, which are marked on both sides for a particular shape. These cams are only linear. Flip it over like a bi-layer CD when moving to another pattern shape. I have seen them in Mint Green and Deep Red.
F-Cam: Black mostly circular tophat cams.
G-Cam: Blue/Periwinkle cams that look like a cross between the A and B cams.
Ahoy!
These waters you tread are dangerous indeed. The sirens are a'calling, and you may find yourself lost before you see a shore again.
We'll be a' talkin' about the Kenmore cams.
/me clears throat
For the Kenmore Experiment, I wanted to help set you all up with what you'll be seeing me work with that isn't really in many modern sewing machines.
PATTERN CAMS!
These little beauties are not really seen with modern machines any more for a number of reasons. One of which being that they just build them all in now for simple mechanical machines, or can program them into the onboard computer and never bother yourself with cams again.
Pattern Cams are actually a fancy name for the mechanic that helps make your stitch shape. Sort of a mechanical instruction for your machine for where the needle is supposed to go, and how the machine should move the fabric.
 |
| Mix of C-Cams and Monogram cams that I sold |
Just like in old computing, different models took their own special ways of getting their instructions. We see the same in the Kenmore family being that there are cams ranging from A through G style. These cams often included two layers of information. 1st layer being the needle position upon a stitch, the second layer being feed dog direction between stitches.
Changing up the position of the needle in the stitch allows for the zig zag, moving left and right based upon a bump or notch on the needle layer of the cam. The motion of the feed dog, allows the change of the position of the fabric for when the needle inserts into the fabric for the stitch. This is how you get your stretch stitches and your back stitches, and get them consistently.
From what I can tell: Layer 1, the larger the radius the farther right, the smaller the radius the farther left. Layer 2, the larger the radius the farther back in the stitch, sort of a stitch length multiplier in reverse. And if it stays back, it stitches in reverse. This is where the pattern length adjuster knob comes in handy. This helps adjust that multiplier with the stitch length. Which means for a 1 layer cam, not having that second layer it is a radius of "0" which means just stitch forward.
With the machines here in my Kenmore Experiment all of them use the C-cams, which are wider cams that have a greater diameter than some of their other cams, but have the top-hat shape. This greater diameter allows for more detailed instruction to be conveyed through the mechanical linkages. As there is more space between the changes in the edges of the cam, and thus allows one to adjust the width and length of the stitch by adjusting the timing of how fast the cam turns in comparison to the feed dogs, as well as a multiplier for the position of the needle to control the width. This is how we get the details of the Tree, and the Swan when it was previously not available in another set.
For C-Cams there are 22 single layer cams (0-19, 53, and 20 is a stretch stitch modifier) 29 double layer cams (21-36, 38-45, 50, 56, 121) and 6 three layer cams (83-88)
 |
| Double, triple, and single |
In very general if you are trying to figure out which Cam you have you may use this link. Other quick indicators are:
A-Cam: Deep Red tophat style cam
B-Cam: Black non-circular tophat cams
C-Cam: Mint Green, Rich Green, Rich Orange (1 layer), Muted Green, Muted Orange (one layer), or White/Cream top hat cam.
D-Cam: Pink/Cream top-hat cam that are roughly the same shape as the A-Cams
E-Cam: Bi-layered open center cams, which are marked on both sides for a particular shape. These cams are only linear. Flip it over like a bi-layer CD when moving to another pattern shape. I have seen them in Mint Green and Deep Red.
F-Cam: Black mostly circular tophat cams.
G-Cam: Blue/Periwinkle cams that look like a cross between the A and B cams.
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