When you try to sew through heavy materials like denim, canvas or leather does your sewing machine glide right through or does your clutch slip? A slipping clutch is when your balance wheel moves but your needle does not. If you feel your clutch slip, you can tighten the clutch screw, but once you feel a slip, it will only get worse. We sew through a lot of thick materials here at Sailrite and that’s why we developed a solution for clutch slipping. It’s called the Posi-Pin.
Available on the Sailrite Ultrafeed Sewing Machines, the Posi-Pin is a patented clutching system that eliminates slipping and provides 100% power transfer from the balance wheel to the needle. Its simple design makes it easy to use and to disengage for bobbin winding.
Why do clutches slip? Let’s explain a little bit about how standard sewing machine clutches work. The most common type of clutch is the friction clutch. This system consists of a long drive shaft that operates the needle, a bushing that connects the shaft to the balance wheel, a washer with small leaf springs, a threaded bushing nut and a balance wheel. The turning of the balance wheel turns the shaft, which powers the needle. The balance wheel is held to the shaft by the bushing and the friction created by the spring washer when the bushing nut is tightened. When you go to sew material that’s too heavy and the force from the needle isn’t enough to penetrate the fabric, the balance wheel works too hard and the friction gives, causing it to slip.
What makes the Posi-Pin unique is that it’s actually a solid pin that goes through the balance wheel and the bushing to lock the two in place, providing a constant positive connection. It disengages easily for bobbin winding and locks back in place with little effort. The Posi-Pin’s strong connection means that you get the most power right to the needle to punch through heavy assemblies, even at slow speeds.
As a safety feature, the Posi-Pin was built with a shear point so it will break before your machine does. If the gears of the machine freeze up the Posi-Pin is designed to snap before causing internal damage to your machine.
Take a look at this video to see the Posi-Pin in action on a machine.
What is your biggest sewing headache? Have you found any ingenious ways to combat it? Share them with us in the comments!