Vertical racking 3: automating half fisherman in pattern (2)

Working with the half fisherman racking discussed in the last post, here is an approach to interpreting the fabric seen below for knitting on a Brother model knitting machine.  500_557For the sample chart, I chose a 12 stitch repeat, making it executable on any knitting machine. The ribber is set to half-pitch. An often-overlooked clue as to what is happening or is about to be found in the arrows just below the racking position indicator. With the latter at 5, the red triangle appears pointing to L. As the bed is racked to position 4, the red arrow now points to the letter R. This is a simple racking pattern involving only the 2 positions, either to R or L

pitch_rack

Once on position 4, the red arrow indicates the direction in which the bed was racked on the last move (R), the “empty” arrow the direction for the next move (L), bringing the position back to 5. More complex patterns require a bit more planning and tracking to avoid errors.

rack2

Racking patterns in books often recommend beginning the fabric with the setting on 5, or the center position for the machine in question.  Doing so allows for balanced edges in patterns that swing by multiple positions in both directions. In this instance, for the sake of avoiding mistakes in as many ways as possible, I would start the pattern on racking position 10. Racking cannot go any further to the right, so no chance for example of racking to 6 rather than 4 in the knitting because of inattention. Having a “cheat sheet” with row numbers where no racking occurs, and the position of the carriage to R or L at their start and or after the knitting is also helpful. I had to lower the tension on both beds considerably to avoid forming loops that in turn got hung up on gate pegs. Especially at the start make certain that the comb and weights drop properly. Using KCI will ensure that the first and last stitch on the main bed always knit. In the patterning used on the Passap back bed (previous post), the groups of needles in each half of the repeat will change to the alternate position with each pass of the lock. On the rows where the back lock is changed to N, selection continues in pattern, but no tucking occurs. In this chart, the pattern is maintained continuously throughout, while blank “remaining” squares are filled in on rows where no tucking or racking occurs = N, every needle knits. In Brother machines, both tuck buttons are pushed in. Selected needles knit, non selected tuck across the row. new program 2symbols

I tested the pattern approach on my 910, with a 38 row, 20 stitch repeat in a random acrylic. I had some issue with some needles not selecting properly, for whatever reason. The repeat was not planned so a full 10 stitches were at each side of the knit, resulting in the difference on the right side of the swatch photo from its left.

larger repeat

half the repeat with color change on a single plain knit row (use of color changer only possible with even row change sequences), the top stripe of the swatch in plain rib

half repeatN1

1rowN1_584

back to scales and knitting them

Overall,  wider repeats and thicker yarns gave me harder to knit fabric, with less noticeable pockets and lack of stretch and “bounce”;  ultimately I went back to a 6X6, 12 stitch 2-row sequences illustrated in the chart above. The thinner yarn needs to be with a bit of stretch, and enough strength not to break when ribbed and racked at the tightest possible tension. This is a fabric that requires concentration, having as many clues as possible to help stay on track is useful. If errors are made close enough to the all knit row, it is possible to unravel carefully to that point and continue on. Mylars or punchcards may be marked to reflect racking position. Here the mark on the right = 10, the one on the left = 9. Marks take into consideration that the card reader’ design row and knitter’s eye level row views are not the same.

mylar_marks

A row cheat sheet can help track carriage location for all knit rows. Pictured below is part of mine. Wording for clues or description of sequences should make sense to the person knitting, not necessarily follow a specific formula.

screenshot_34

some of what “did not work”, including a very long swatch with a confusing pattern due to creative operator error

500_591a finished piece with yarn ends not yet woven in500_590

The fabric is tugged lengthwise, left unblocked, and pockets may pop on either side of it, with the majority on one side of the knit as opposed to the other

the start of a series in varied colors and fibers500_604

Tuck and garter stitch: from hand knit to machine knit hand tech pattern

A Ravelry question on the possibility of executing a particular fabric on the machine has led to the experiments in this post. The pattern that led to the discussion is a free hand knit one,  shared and published on the Purl SOHO website and on Ravelry. The gauge for their project is 4.75 stitches = 4 inches in stitch pattern, it includes garter rows. Such rows may be executable on home knitting machines by transferring from ribber (Passap front bed) to main bed, alternating with reversing the process at a predetermined frequency, depending on stitch type. K1b is the hand knit equivalent of tuck for that stitch on that row, adding to the mix.  Not practical for G carriage use, as the latter does not form tuck loops, and hand retooling would be required for all k1b stitches.

Using holding to create tuck stitches in non-auto patterning days was commonly used, and I chose to do so here. As machine knitters, we are conditioned to believe that single color rows are impractical to execute and that the yarn would need to be cut on each side after the one row. Color changers are on one side or the other, making striping with frequent color changes is practical if executed in even multiples of rows. Transfer carriages are available that will help move stitches from one bed to the other, I personally have never had the patience to work with them enough to get good at using them without dropping stitches, so I went back to even lower tech than usual, using the garter bar on the bulky, and beginning pattern row 1 with COR.

Before attempting nearly every row turns, it is helpful to have some practice with turning work over using a garter bar, develop a sequence of repetitive actions, keeping careful notes as to what works for you, and using contrasting yarns in tests to better understand stitch structure. In my sample the white yarn was thicker than the blue, reversing colors or balancing yarn thickness would change the visual look of the fabric.  Beginning on small samples helps work out issues and the making of the decision to try on a larger project or simply as a border.

Analyzing the pattern repeat:

screenshot_43tools to help with EON needle selection tools

the results of rows beginning with k1 sequence after the row is knit, note the “tuck” loops on top of E position needles, which will be knit off on the next row knit K1_after knit

a row that begins with a k2 sequence, before it is knit; the needles holding the single, blue stitch will form the loops on top of the needles as the yarn moves across to the opposite sidek2_before knit

E position prior to transferring stitches onto garter bar, also for a free pass to the opposite side to pick up yarn after stitches are removed on bar free pass473

1            begins and ends with K 1; COR select needles, col A * knit row, COL, bring all needles out to hold, remove on garter bar, free pass carriage to theopposite side, COR, flip garter bar over, replace stitches onto needles push all stitches against gate pegs *

2            begins and ends with k 2; COR select needles for row 2, col A repeat * to* end COR

3            begins and ends with k1; COR select needles for row 3, change to col B, knit one row, do not turn, do not cut yarn; COL bring all needles out to hold, a free pass to the right to pick up col A on next knit row, end COR

4            begins and ends with k 2; col A, COR select needles for row 4, repeat from * to *

5             begins and ends with k 1; COR select needles for row 5, col A, repeat from * to * do not turn

6            begins and ends with k 2; COR select needles for row 6, change to col B, repeat from * to *

publisher’s project photo

beautyberry-blanket-600-12-315x441

my swatch, knit on a whopping 9 stitchesrav blanket 300


 

Thread lace and punchcard knit carriage use on Brother 910_2

A short while ago there was a Ravelry thread discussing reversible, double bed knits. I recalled a demo from eons ago I saw at a machine knitting seminar and decided to explore my memories and share. The result approaches a “reversible” fabric, with imperfect results depending on yarns used and other factors. There is a group of knitters that are presently experimenting with “glitch knits”, where the intent is to purposely create patterns with what some people might consider “mistakes” as purposeful parts of the design. For one example see a video of the technique. The “imperfections” in the fabric below may be seen as a positive by some. It is not the result of any aberrations in the programmed pattern, but rather a result of the way the threads get pulled through each other as the carriage moves across each row knit.

My samples were knit using equal weight yarns. The fabric may be better served by using different weights, approaching the usual recommendation for plaiting. See the manufacturer’s directions for plaiting feeder use.

Cancel end needle selection on your knit carriage. Cast on is for full needle rib with both yarns in place. Hang comb. Knit 2 circular rows followed by one more all knit row. Change to rib tension that has been tested for yarn combination if your cast on was tighter than it. Several rows may be knit for a “solid” color edging.

When the first pattern row is selected, one need not set the KC carriage to slip. N is king in Brother, regardless of pattern/ needle selection as long as no cam buttons or levers are pushed in/ selected, everything knits, whether single or double bed. After the first row of the pattern is preselected on the main bed, use a tool to push in both buttons as seen below, and proceed in the pattern. Even though end needle selection has been canceled, if the end needles on the main bed are selected, they need to be pushed back to B position or those stitches will be dropped

my punchcard carriage set up on one of my 910s
setup_50

when testing motifs it is always good to begin to do so using a simple pattern, making needle pre-selection easy to view and check. I began with “checkers”. They can be viewed at the bottom of the image below with the machine set for double length, at the top as drawn on the mylar; most such fabrics are well served by double-length on any machine, electronic machines could easily vary the repeat size or color reverse at the flip of a button, using lili buttons on ribber may add to the mix of results as well.
screenshot_22a familiar stock Brother punchcard, knit on my 892, double-length screenshot_23Review of the use of plaiting feeder from Brother ribber manual 

 

Thread lace and punchcard knit carriage use on Brother 910_1

Yes, the 910 has no thread lace setting. I happen to also own a punchcard machine model # 892E (no idea why Brother chose to add the E to a punchcard model name). I remembered eons ago reading about someone on an Australian list actually getting a punchcard model carriage to work on an electronic machine. It is good to beware that not all carriages may be interchanged between different models, especially if the latter were manufactured several years apart.

The magnet on the back of the electronic carriage is what trips the reader in the 910. With the 892 and 910 carriages side by side, I marked the approximate spot I wished the magnet to be. It is presently in place with cellophane tape for my tests. I believe it to be a “rare earth magnet”, 12 mm in diameter, part of a jewelry piece from days gone by, with a deep attraction to all KM metal parts.

spot39the first location was too high, the pattern did not read properly place40what turned out to be a much better spot  better placea random mylar repeat mylar45the resulting fabric, on both purl and knit sides both sides

I used two cotton yarns, with a slight difference in weight. With the exception of when knitting transfer lace, the first instinct may be to use the color reverse option when the mylar repeats show lots of “white squares”. However, in this type of fabric blank squares knit both yarns; black squares or punched holes knit only the thinner yarn, while the heavier one floats behind it. The KC tension used needs to accommodate both yarns easily knitting together. When only the thin yarn knits on selected needles, the stitches formed will actually be larger in size than those where both yarns knit together, giving the “illusion” of holes.

This fabric was also at times referred to as punch lace. It is only possible in Brother machines that have 2 cam buttons in the center position, both center buttons under the MC/L mark are depressed. The punched holes/ black squares in mylar select needles that will knit in the fine yarn only. If you are using a very fine yarn for the second yarn, you may have to wrap it twice around the dial on the mast tension unit to control its feeding. Better edges are produced by canceling end needle selection or manually pushing any selected end needles back to B. If KCII is an option on later electronic models, some of the work is done for you. End needle selection may also happen as part of the design repeat, so in those instances, unless you are happy with the thin yarn only knitting on the very edge of the fabric, those needles need pushing back to B by hand as well.

selected needle

end needle camsset camsBTW: end needle selection must also be canceled whenever patterning with needles out of work is used, or needles on both sides of out of work ones will produce knit stitches regardless of programmed pattern.

If a contrasting color is used as the thin yarn in the B feeder, the results may be seen below. Note: the colors appear reversed to their position in feeders, so A (thick) color is seen more on the purl side, the B (thin) is more evident on the knit side of the fabric. The top of the swatch shows the result when blank rows are programmed into the reader. Sometimes this setting is used as an alternative to replacing the standard A/B feeder with the machine’s plating feeder (if available for your model km). Reversing yarn position can produce some interesting stripes

combo colornot all A/B yarn feeders are created equal 
sinker plates

I have always found the extra B gate on left more a nuisance than a necessity, particularly if the B yarn needs frequent changing.

Another unconventional use for this setting to produce “pretend cables”

thread_lace

It is possible to knit thread lace with the plaiting feeder in place on the single bed as well. The effect approaches glitched versions of the pattern, Stitchworld #407. This is a quick hack to keep the front yarn from slipping out of the yarn feeder The blue and white yarns are equal in weight, the orange replaced it and  is thinner

Picot cast on for every needle rib

Depending on the sort of rib, the beds need to be aligned in most instances so that the needles on opposing beds line up between each other. For this ribber cast on the beds start at full pitch, as you would for EON knitting. Every other needle is brought in to work. A first “zigzag” row is created at the tightest tension possible. On the second row, the alternative needles need to be worked. On Passap E6000 BX, LX with pushers under new needles only will help do the job. On Japanese machines: bring the new needles out to hold, set both carriages to slip. This will result in only those “new” needles knitting on the next pass. The outcome will be one zigzag crossing over the other (red over blue in the photo). Prior to the third knit row, reset the carriages or locks for circular settings (CX/CX, opposite part buttons). Because all stitches will be knitting on each bed, loosen the tension to about three-quarters of the rib stitch size, knit two rows, change racking handle/lever and needle positions to half pitch at their completion. Adjust tension to desired rib stitch size, knit a closing “zigzag” all knit row at tension used for the remaining knit, and proceed in rib
The method may be used both for every needle and for every other needle rib.
The configurations for each, colors are in reverse order from photos that follow

first zigzag rowzig zag onesecond zigzag row (contrast color for illustration purposes)zig zag 2hang comb, knit 2 circular rows circ_combchange racking position and needles alignment rackchange tension, continue in rib, knitting all sts both beds 300_2423detail close up detail

Racked ribber cast on and rib configuration tips

This cast-on (on any ribber) is capable of giving a softer, looser start and is good for fabrics that stretch. It is described in most machine knitting manuals.
When experimenting, check the alignment of needles physically before proceeding for knitting ribs on all needles. In Brother machines, the racking grip handle is used in creating “racking patterns”. By turning the grip handle the ribber bed is moved to the right or to the left. The racking position is indicated on the racking indicator. Usually casting on is begun with the indicator in the center position, #5. As indicator numbers rise the ribber moves to the left, and as they decrease the ribber moves to the right. The two cursors can be moved and set to use as an index of the racking range. I prefer to track racking positions in other ways ie. with punchcard markings when possible. The arrows L and R indicate the racking movement and will change position after each handle turn reversing direction is completed. The pitch is set to accommodate rib configurations. In the P position needles on each bed “plain and purl” are directly opposite each other and in a collision course. If EON (every other needle) on each bed is in use, then this position is used to center needles on opposite beds between each other. In position H the ribber needles are centered between two main bed needles.
If observing a suggested needle rule, set up needles using it.
Rack one full number to put the needles out of the rule, and knit one row at about 2 numbers tighter than the final setting.
Hang the comb and wights, and rack again to the original position. Add any edge stitches that may be needed for the specific knit fabric. Knit one row across stitches using the final tension setting.
For every needle rib cast on in my sample I began with the racking indicator on 6, COR, knit zigzag row to Left. Note: at the start of the process, on the left side,  the first needle is in work on the top bed.  The ribber is then racked to position 7. The first needle on the left is now in work on the ribber.  A row is knit from left to the right. The ribber is then racked back to its original position (6). The first needle on the left will once again be on the top bed, and the first needle on the ribber to its right Continue in the planned rib.
Often manuals give suggestions as to the “needle rule” for each type of rib. The sequence below is knit on a Passap. It, in theory, would produce a 2X1 “industrial rib that could transition to every needle or main bed knitting without any holes at the transition point. Note here there is a needle in work between each pair of needles on the opposing bed.

IMG_2390“zigzag” row, normal needle position: work slowly, make certain all needles have picked up yarn
1hang comb: the first needle is in work on the back bed on the far left 2rack one full turn to the right: the first needle in work on the front bed is now on the far leftIMG_2382knit one row  4rack back to the original position, and continue plain rib  5There are sources online including videos that recommend circular rows at this point, they are actually unnecessary. The other recommendation made by many after any ribber cast-on is for 3 circular rows. There is no need for the third circular row. It will actually create a visible line across one side of the rib, that is noticeable, and may not be wanted if it is on the “public” side of the finished garment.
To fill in potential holes produced when empty needles are brought back into work, bring all empty needles into work, and tuck one row across both beds, making certain loops are formed on each needle IMG_2391knit 2 rows circular slowly, some needles hold 3 loops of yarn, switch to ENR rib
the result at rest
rib1rib stretchedfirst rib stretchGoing for a rib with more of a 2X2 look: set up needles for rib pattern, there are still 2 needles in work, one not, on each bed. The empty needle space is now at the center of each pair of needles on the opposite bed

IMG_2392rack one full turn to the right, and knit one row IMG_2393hang comb and weights IMG_2396rack back again to “needle rule” position Knit one row at final setting, proceed for ribIMG_2397at the top of the rib knit 2 rows circular, proceed on EN ribIMG_2399

tension adjustments may make a big difference, my samples have been knit at the same tension throughout, and single-ply throughout

the first rib at rest rib2stretched second rib stretchBoth instances produce a reversible rib
Some experimenting is required to achieve cast-on rows in the rib that is not too loose or too tight. In this instance there has to be enough slack in the loops so that there is room for racking one full turn, too much will leave loops. Loops created by cast-ons with deliberately large stitch sizes may, in turn, be chained off with a latch tool. The stretch factor and weight of the resulting rib also need to be in balance with the remaining knit fabric. If “improvising” it is always advisable to keep good notes. Most publications and how-tos are really guidelines, starting points for investigating what may be the best method to use in any one piece.

A variation: a racking cast on at a large stitch size can be chained with a latch tool after the work is off the machine to make an edge that nearly matches a chained-off bind-off. It is useful, especially in rib tuck fabrics.
Set up needles in the needle rule and rack out of the needle rule.
Knit one row at a large stitch size, moving slowly to the opposite side. Testing will determine the tension the specific machine will tolerate with the yarn being used.
Check that all needles have picked up loops.
Hang the comb and weights and rack back to the needle rule.
When off the machine, use the method described in the post Ribber cast ons: breaking the “rules”

Transitions in ribbing from EON to FNR fabrics

It is always helpful to use a familiar yarn when testing techniques and to have some idea what baseline tensions produce each desired fabric before combining fabric types, structures, and techniques. This will ensure that the knit result will be both manageable to produce, and will match your desired concept.
Any time an empty needle is brought in to work, the first knit pass will create a loop on the empty needle; the second pass will form a full stitch, resulting in a hole. This is seen in lace transfers or when bringing empty needles into work closes single ladder spaces.
Use garment yarn double thickness in the EON needle rib if the aim is to produce DBJ, which will yield a different thickness knit. Test for other fabrics ie patterned English rib, etc. Swatching is worth the effort, avoids producing whole pieces where combined results are disappointing.

EON rib set up for your brand machine
Knit 20+ rows
End and begin the test with COR; trim off one yarn end, to be woven in using your favorite method
Racking handle at half pitch
Bring all needles into work both beds
Observe the needle rule appropriate for your double bed fabric Set both carriages or locks to tuck
Reduce stitch size tensions by one whole number, knit one row, which will produce a “zigzag” across all needles, with a loop on each needle, both beds
Set both carriages to knit circular; this will be a slipstitch, tension may need to be loosened by one number to accommodate the added yarn, knit 2 or 4 rows
Set both carriages to knit, enlarge stitch size one or 2 numbers if needed, knit one row
Proceed as required for pattern

Depending on which direction your first row of “garment” fabric needs to be selected if using a color changer, planning for that may affect which side of the machine needs to be your final location before knitting the first row of pattern.

The swatches below illustrate the transitions, are in their “just off the machine” state. I used the same tension throughout. The EOR rib was knit single strand, the resulting difference in width is easily seen, though the density difference is obviously not observable in a photo.  The yarn used is one of my “throw-away” acrylic/ wool blends.

side 1 “holes”
holes frontside 1 “no holes”no hole frontside 2 “holes”holes_backside 2 “no holes”no hole back

Unconventional uses for punchcards 1: tracking racking positions in ribbed fabric

In a long-ago post I shared the punchcard image below. The card is used double length throughout. Cast on in your favorite method.  “Memorize” the first row of pattern, set card to advance EOR, set KC to tuck in both directions, set RC (ribber carriage) for normal knitting throughout. This is a racked pattern. The numbers to the right of the card are for the racking position on each visible row (takes into consideration your eyes can view card 7 rows above card reader teeth). There are only 2 positions in this card as written, 4 and 5, so the results are vertical columns in a textured rib

checkerboardthe corresponding swatch, both sides are shown 

The tracking for the racking sequencing may be created for any punchcard, whether punched holes are required in the card for patterning or not. The image below is taken from the Brother Ribber Techniques Book. If KC is used, no holes are punched, and the carriage is set to plain knit, though the card advances, all needles knit. End needle selection is not a factor. page 17

the racking handle movement repeat isolatedworking repeat

In the card, for use on Brother, the first row of the repeat with the machine on racking position 10 would be placed on row one pre-marked position found on stock brother blank cards. Always check markings for your machine. I have a roll purchased for Brother kms specifically that actually are stamped for Studio, with # 1 two rows below where it should be on right.  No holes need to be punched in this instance. Needles are brought into work and filled as illustrated on the ribber book page. Knit one row across stitches with the card set to advance normally. In this instance marking row numbers in preferred colors will indicate when the racking sequence changes direction. Green rows rack to left, orange to right. The racking handle position repeat is 20 rows high (shown on left), a minimum of 36 rows for the card to roll properly) is met by repeating it twice, and the “motif” is broken up to accommodate the fact that the reader is working on 7 rows below the row number visible on the machine exterior. Rows 34 and 35 would become the 2 every square punched rows always placed at the top of pattern cards. The blue numbers on right reflect the racking handle position for that row before the next row is knit. They can be marked on any blank square if the card is blank, or alongside existing row numbers as seen in the punchcard for the checkered swatch. It is helpful to have consistent habits if one needs to stop for any length of time ie. always knit row, rack to position or stop after knitting, rack upon return.whole card

The machine can be set for double length for racking after every 2 rows knit.

Using the method for cables and crossed stitches  (3 posts)

Lace cards on 260 bulky PDF

Brother KMs: punchcards and their use

I have recently become involved in a year-long project at UMass Lowell and will share details as they develop. Most of my blog posts are written for those who already have a basic knowledge of techniques. Since I may soon be involved in teaching basics to non-knitters on Brother models, I am in the process of getting some informational notes together and thought I would share them here as well.

The first 24-stitch punchcard readers appeared in the mid-1970s.  The reader sits on the far right of the knitting machine; it actually reads 7 rows below the row visible at eye level on the machine exterior, establishing a numerical relationship between motif repeat design rows and those viewed

reader

cards may be purchased pre-punched (1), as individual 24X60 blanks, or in continuous rolls (2); a card punch (3) is used to punch holes card_suppliesrows: for any card to roll in a continuous pattern vertically (rows), cards are joined to form a roll. A minimum of 36 punched rows is required. Snaps are used to join the beginning and end of a single card or multiple cards sequentially. There are excellent, free downloads now for pattern books including designs for all varieties of MK fabrics. It is possible to have the machine knit rows in double-length ‘automatically’, it is the only built-in possible alteration of the pattern. Masking or cello tape is a temporary solution to testing repeat variants or to repair errors (both sides of the card), otherwise re punching of the whole card is required for any changes

stitches: the maximum repeat width (stitches) is 24, 24 squares, one line on the card. On Brother KMs the repeat is centered with 12 stitches on either side of the center “0” marking (2). The needle position indicator is marked in thick and thin lines (1), each representing one whole design row repeated in width. If one wishes to shift motifs on the knit piece, invisibly join designs, etc., the only alternative is to determine the width and needle locations required and then to shift the knitting position on the bed by repeat or its segments.

needle tape

motifs must fit together within the 24 stitch limit, so individually they must be factors of that number: 1,2,3,4,6,8,12,24 (height calculations must have a minimum of 36 rows punched, so different math is involved there as well)

anatomy of a card: all squares are punched top and bottom for 2 rows each. They are not part of the design and overlap the first and last pairs of rows respectively when snaps are in place. Hence, the design motif remains continuous.

Any image will be reversed on the knit side, of note in planning lettering or motifs where direction matters. With the change knob set to KC or SM punched holes in the card will preselect needles to the B position, unpunched holes will leave them in the B position. A 24-stitch repeat with needle selection for row 1 (card is from a set supplied by Brother with machine purchases).

anatomy

Markings as they appear on the needle bed:    The extra markings on the needle tape in my machine are water-soluble ink marks from one of my projects to help track techniques.
End needle selection: The card in place in the reader: Working with motifs in networks with 24 stitch limit: checkerboard is formed with the isolated motif, originally measures 8 stitches by 16 rows; repeats in the charts below are outlined in green, and colored squares correspond to holes punched in the card

checkerboardadding simple patterns adding shapestaggering horizontally for brick repeat (now too wide for the card) horizontal staggerstaggering vertically for half drop repeat, (row adjustment)vertical staggercheckerboard begun with an 8 stitch repeat straighthalf drop: repeat begins to change in width half dropbrick bricktriangle triangleadded larger repeat variationsvariation 1

variation 2

variation 4

Electronic machines are able to use punchcard designs as well. Only one pattern repeat needs to be programmed. Factors of available maximum width in stitch repeats depending on machine brand:

24: 1, 2, 3, 4, 6, 8, 12   30: 1, 2, 3, 5, 6, 10, 15   40:1, 2, 4, 5, 8, 10, 20  60: 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, 30

More to ponder: knit stitches are not square, they are rectangular, so representational knits, no matter the size, require some mathematical adjustments to retain their aspect ratio. An interesting illustration of this is seen in attempts to knit a circle.
Common ratios for knitting are 4:5, and 2:3 (height to width) with stitches usually wider than tall.
Gauge is the stitch-to-row ratio that allows one to calculate height and width for finished knit pieces, it is the basis for creating and shaping the items which in turn may then be assembled into garments or size-specific end products.
The Diophantine equation (referred to in knitting as the “magic formula”) may be used to calculate increases, decreases, and shaping. There are many excellent how-tos and calculators to aid in the process. The old Brother accessory calcuknit and its emulator took some of the “work” out of the process and were later replaced by similar functions in consoles or software. Sometimes charting out the shapes based on such calculations was referred to as “ragu charting”.

A postscript: punchcard machines continued to evolve and became easier to operate over the years. Those markings on the end of the needle bed did not always skip the letter C. The KH 800, 1971-72 which preceded 24 st punchcard models, had several more needle positions, including the now-missing C 

An illustration of one of its fair isle cards and accompanying instructions for the accompanying settings