solowiej

Hello! I finally found a reasonable sounding deal on a cylinder arm machine. When I went to pick it up the small parts that were pictured in the sale: Bobbin case, bobbin cover and presser foot, had all been lost. I had already paid for the machine and driven there so I took it home with me. I haven't found much info on the Necchi 840-100. Based on this thread on the very similar Pfaff 335, I ordered some cheap bobbins and cases online. They don't fit. The center hole for the bobbin case is slightly too snug to fit onto the center pin on the Necchi. The bobbin post on my rotary hook measures 4.4 outer diameter. These bobbin cases measure 4.3mm inner diameter. Could this be a matter of polishing the (cheapo) bobbin cases a bit further open so they fit? Anybody have advice, or know of a solid parts source for the Necchi 840?

I'm trying to reduce the volume of the machine when I'm not using it, which is my attraction to a smaller body-mounted motor like your WorkerB setup. Striving for a stage in between the oversized (for me) industrial table and the underperforming (for me) Sailrites. And right now until 2/19 the WorkerB is on sale for $225. Are you happy with the torque from the WorkerB motor, and what have you tried it on so far?

Splendid work. I think you've answered my first big question, which is whether the controller and motor parts can be found separately to save $$ and not have to buy a new kit from Sailrite just to cannibalize it. Sounds like the controller is proprietary and not easy to replicate. That said, I imagine there are a bunch of forums out there openly discussing this stuff. Basically a small Arduino or even ESP32 board, a power transformer and rotary pot switch in a 3D printed case, plus countless hours of learning with trial and error could replicate the controller functions and more. ? Super cool that you're programming stitches with Arduino! I'm not too worried about the setup blocking the head's tip-back, as I can get around that for bobbins and maintenance. I'm on enough of a budget, plus experienced just enough to be happy with my clutch motor, that I'll let the current Sailrite sale end on the 19th and keep looking for individual components and insights. Please keep sharing your project! It's an inspiration.

Wonderful info! This is exactly what I've been hoping to do with my DNU-241 (Mercury branded). I'd love to see pics. If you're comfortable, do you mind starting a new thread with pics and the info from your adaptation? I imagine others will also be interested. I'm also curious if you've looked into sourcing a motor and controller separately for this. Sounds like the combo (proprietary?) transformer / controller unit might be the lynch-pin.

Thank you Quade! Sounds like exactly how I would measure it. So maybe you did something like what I'm scheming over and ordered the Worker B kit to apply it to a different machine than intended. If so, can you share how you applied it and how it went for you? Even if you did apply it to a Portable Walking Foot / Sailrite type machine, do you mind sharing any available info or part numbers for the motor, controller and foot pedal? Seems a shame to butcher a new kit just for components, when those components must be available out there somewhere (and ideally cheaper).

Nope. I'm hoping to adapt a monster wheel to my DNU-241. If the Sailrite shaft is wider than 14.7mm I'll need a shim, if it's narrower I'd need to put the flywheel/pulley on a lathe and open it up.

I've been searching fruitlessly for the diameter of the pulley shaft on the Sailrite (and clones) portable walking foot machines. Anybody know offhand or have one to measure?