JACK A4C‑CHL‑7

The double-capacity hook carries a larger bobbin, so the machine runs longer between bobbin changes — the stop that costs the most time on long, thick seams. Feed force is managed by JACK's NTB system: the Octopus Nine-brain AI chip reads the material as thickness changes and sets the feed force on its own, while the 0-degree thread path lowers thread tension so the thread breaks less often.

Everything else is the A4C you already know: automatic thread trimmer, presser foot lifter, backtack and needle positioner, stitch length set by stepper motor in 0.1 mm steps, central oil-pan lubrication and a USB port on the head. It ships complete with table and stand.

What's Included

• JACK A4C-CHL-7 single needle lockstitch machine head (ships assembled)
• Integrated direct drive motor with built-in operation panel
• Industrial sewing table and stand
• DP×5 (#16–21) needles and bobbins for the double-capacity hook
• Standard presser foot and accessories
• Operator's manual

Key Features

• Heavy-material version of the A4C — factory-configured for thick work, not an apparel machine pushed past its range
• Large double-capacity hook — bigger bobbin, longer runs between bobbin changes
• DP×5 (#16–21) needle system — needle sizes made for thick denim, canvas and vinyl
• 7 mm maximum stitch length — long, strong stitches for heavy seams and topstitching
• NTB system with Octopus Nine-brain AI chip — adjusts feed force in real time as material thickness changes
• 0-degree thread path — lower thread tension and fewer thread breaks
• Fully automatic — thread trimmer, presser foot lifter, backtack and needle positioner
• Stepper-motor stitch length — set to 0.1 mm, with quieter backtacking
• Three function buttons at the needle bar — half stitch, add a stitch and backtack, without reaching for the panel
• Direct drive motor built into the head — no belt, quiet running, lower power draw
• 3,500 stitches per minute — speed matched to heavy-material penetration
• 13 mm presser foot lift — clears stacked, thick assemblies
• Central oil-pan lubrication and USB port on the head for a fan or phone charging

Ideal For

• Thick denim and jeans construction — heavy seams and multi-layer joins
• Workwear, uniforms and heavy garment production
• Canvas goods, bags and heavy totes
• Vinyl, coated and laminated materials
• Footwear and shoe upper assembly
• Awnings and outdoor heavy textiles
• Long heavy seams where bobbin changes slow the line down
• Shops already running the A4C that need a dedicated heavy-material station with the same controls