One of the worst things about sewing is finding out that your bobbin — that’s the smaller spool that works together with the needle and the larger spool to make a complete stitch — ran out of thread several stitches ago. If you’re lucky, the machine has a viewing window on the bobbin so you can easily tell when it’s getting dangerously close to running out, but many machines (ours included) must be taken halfway apart and the bobbin removed before it can be checked.
Here’s how it works: load up the clever little acrylic slide with up to twelve empty bobbins, then dial in the speed percentage and press the start button. The bobbins load one at a time onto a drill chuck that’s on the output shaft of a beefy 775 DC motor. The motor spins ridiculously fast, loading up the bobbin in a few seconds. Then the bobbin falls down a ramp and into a rack, and the thread is severed by a piece of nichrome wire.
An important part of winding bobbins is making sure the thread stays in place at the start of the wind. We love the way [Mr. Innovative] handled this part of the problem — a little foam doughnut around a bearing holds the thread in place just long enough to get the winding started. The schematic, BOM, and CAD files are available if you’d like to make one of these amazing machines for yourself. In the meantime, check out the demo/build video after the break.
When the Red Bull Creation build days were past, [David] pulled us aside and asked if we wanted to see the mechanical hack he’s been working on. He built this rope braiding machine, which uses 16 bobbins, with help from his brother [Jed].
Ideas for projects always come from funny places. [David] came up with this one after finding a rope braiding machine at Ax-man Surplus. This outlet, located in the Twin Cities (Minneapolis/St. Paul, Minnesota) has been the origin for innumerable hacks. Just one that comes to mind is this electric scooter project from the ’90s.
[David] wanted to understand how the mechanism, which divides the bobbins up into groups of orbiting spools, actually works. It’s both mesmerizing and quite tough to visualize how it works without really getting in there and looking at the gearing. Thankfully you can do just that if he follows through with his plan to turn this into a kit.
[glacialwanderer], who you may remember from his CNC machine build, recently completed an electric spinning wheel. Spinning wheels are used by knitters to turn raw sheep’s wool into yarn. He went through several iterations before arriving at a good design. Besides the motor, there are two major components to the spinning wheel: the flyer and the bobbin. A Scotch tension brake is used to slow the rotation of the bobbin in relation to the flyer. This causes the wool to twist as it’s pulled on.
He initially tried to just use a dimmer switch with an AC motor. That quickly burnt up. The next version used a sewing machine motor since they’re designed with a variable speed control. Unfortunately, it didn’t have enough torque at low speeds. The final design used a DC motor with a SyRen motor controller. It offered plenty of power and at ~$150 it’s still less than the cheapest commercial models on eBay. You can see a video of it and the spinning process embedded below.