Tension

Overview

The Knitting Machine Tension Settings are crucial for controlling the flow of yarn to the Carriage and ultimately determining the Gauge of the knitted fabric. Both the Tension Mast (or tension pole) and the carriage's stitch size regulator (often called the lock tension dial) influence the final stitch and row dimensions.

Components and Their Influence

• Tension Mast: This device feeds the yarn to the carriage and controls the rate at which the yarn flows. It typically features a tension dial with various settings.
• Carriage Stitch Size Regulator: Also known as the lock tension dial, this setting on the carriage primarily controls the size of the stitches formed on the needles.

While a general consensus suggests that the carriage tension dial affects stitches per inch and the mast tension controls rows per inch, both mechanisms ultimately influence the overall gauge of the fabric. Swatching at different settings for both is essential to understand their combined effect on a specific yarn and pattern.

Machine-Specific Tension Settings

Knitting machines vary in the number and type of tension settings available.

Passap Machines

Passap machines typically feature 13 tension mast settings, numbered 1 through 7, including half-space increments (e.g., 1, 1.5, 2, etc.). Setting 1 is generally the loosest. Passap patterns often provide specific tension recommendations for both the lock stitch size regulator and the tension mast. If edge stitches are too tight or unknitted, lowering the tension disk setting is recommended.

Japanese-Style Machines

Japanese Knitting Machines commonly have five tension mast settings, often marked from '-' (loosest) to '+' (tightest). Unlike Passap, patterns for Japanese-style machines frequently omit specific mast tension recommendations.

Silver Reed LK Series

• Silver Reed LK-140: This machine has seven tension settings on its carriage, with one click between each setting.
• Silver Reed LK-150: This machine features nine tension settings on its carriage, with one click between each, plus additional settings (10 through 13) for every-other-needle operation. The tension pole setting on these machines is designed to match the carriage tension setting to securely hold various yarns.

Factors Affecting Tension and Gauge

Several factors beyond the dial settings can influence the effective tension and resulting gauge.

Yarn Characteristics and Fabric Treatment

The slipperiness of the yarn and how the knitted swatch is treated after removal from the machine can impact the final stitch-to-row factor.

• Tubing: Rolling the piece lengthwise and stretching it to set the stitches.
• Dressing: Applying steam or laundering the swatch.

Measuring a swatch before and after dressing can yield different results.

Lint Accumulation

Lint and yarn fibers can accumulate within the tension mast's mechanism, particularly between the tension disks and around the spring. This buildup can impede the free movement of parts, leading to inconsistent tension. Regular cleaning of the tension dial is crucial. When dismantling for cleaning, it is advisable to take apart only one unit at a time to ensure correct reassembly.

Tension Mast Assembly Health

The physical condition of the tension mast components, particularly the take-up spring and thin upper yarn guides, is vital for consistent tension.

• Take-up Spring: The spring mechanism should move freely and spring back effectively.
• Thin Upper Yarn Guides: These guides can lose their "spring" over time, leading to slack yarn and loops on the selvedges. A simple test involves threading both guides with the same yarn, setting tension dials identically, pulling the yarn backward, and releasing. The ends of the yarn guides should bounce up to approximately the same height. If one guide remains significantly lower, it may need replacement. It is recommended not to leave yarn threaded through the guide with pressure applied for extended periods.

Tension Mast Styles

Different machine types and accessories may utilize distinct tension mast designs.

Passap Tension Masts

Due to their inherent double-bed design, Passap machines typically use a single style of tension mast.

Japanese Machine Tension Masts

Japanese-style machines may have different masts depending on their function:

• Regular Mast: The standard mast supplied with the machine.
• Color Changer Mast: Designed for use with a color changer, this mast often features heavier gauge metal for the thin upper yarn guides and stronger springs. This increased pressure is necessary to maintain proper tension on yarns that may be held in reserve for many rows, preventing slackening and loops along the selvedges.

It is important to note which mast was used when swatching, especially if multiple masts are available, to ensure consistent garment sizing.

Maintenance Tips

• Regular Cleaning: Frequently check and clean the mast tension dial for lint and yarn pieces.
• Check Spring Health: Periodically test the take-up spring and thin upper yarn guides for proper movement and rebound.
• Mark Settings: Mark the center point of the tension dial to make settings easier to read and replicate.