Uwe

Since your budget is limited, you'll probably get a Golden Wheel, the brand of the Chee Siang Sewing Machine company. Luckily, Chee Siang is one of the very big companies that produces high quality copies of many original designs. They make nearly everything, or so it seems. I have yet to find a famous machine design that they don't make. The Golden Wheel brand doesn't have much of a presence in the U.S. But I strongly suspect they are behind many of the aftermarket brands that are sold in North America. Check out the website at http://www.golden-wheel.cn/en/product-2 in the "Heavy Duty" section, either under Flatbed or Cylinder bed. Each of these categories have a "Unison Feed" section. There you will find all the candidates for your work. For example they have cylinder arm machines of Juki TSC-441 (CS-441) , Durkopp Adler 205 (CS-205), and Pfaff 335 (CS-335) designs. That small sample right there covers the majority of machine designs people on this forum use and recommend. On the flatbed side, check out their version of the latest Durkopp Adler 867 design, the CSU-8671 (not cheap, but it's the machine design I would buy new right now - it's bound to be a future classic.) The other flatbed unison feed machines are all designs you'll recognize from discussions on this forum. One other nice part is that Golden Wheel posts most manuals right on their website, which is how it should be. They also make and sell parts for their machines, not all aftermarket companies do. Good luck with finding a nice machine!

Sold to a good home in Indiana.

Yes, the motor is just a temporary test setup to check stitch speeds and take measurements. I'm building a proper table for the machine to get it ready for demo (and sale.) I'm not sure exactly what parts are involved to add reverse to a Singer Class 7, so I don't know which Singer 7 subclasses are compatible with the retrofit. I know Singer Class 7-31, 7-33, and 7-34 can have reverse, but there may be more.

Some Singer Class 7 models can be retro-fitted with reverse. The lever is on the back and usually operated via foot pedal or pneumatic cylinder. With the right motor control you can even program automatic back-tack and other tricks. Adjustment screws at the top and bottom allow to balance forward and reverse stitch length. Here's a picture of my 7-31 that has the retrofit reverse lever:

I'm still putting my money on the top thread snagging somewhere below the throat plate. You don't get big loops of top thread underneath like that unless more top thread is pulled from the spool at the wrong time, leaving the take-up lever without a chance to pull the knot tight. I may sound like a broken record to some: Take the belt off the hand wheel and do a few very slow, hand-turned stitches and really look, feel, and listen for anything that is not how it should be. Knowing how things should be is often the hard part. "Smooth and without hang-ups" is a good starting point.

The picture may indicate something else in the thread path going on. Your top thread path may not be right. Your top thread may snag somewhere as it wraps around the hook and bobbin. Maybe the bobbin case opener doesn't work right. As for the tail of the bobbin thread after installing, you pull it up through the feed dog hole. Hold the top thread and make one manual turn. Make sure the bobbin thread is under the tension spring of the bobbin case and that you have very light tension as you pull the thread (30-50g) This Juki DNU-241H manual (http://www.raichert.com/adobe/dnubook.pdf) has a little more than the basics.

The picture doesn't really tell me much detail about how you're loading the bobbin. For remote debugging, you're going to have to give us little more to work with. What model Juki your machine is and what do you mean by "isn't panning out". Do you have a user manual for the machine? What does the manual say about loading the bobbin? If you don't have a manual, have you looked for one online?

Juki is happily mixing metric, SAE, and specialty Singer threads on their machines. Sometimes they're just messing with you. The 15/64-28 is in the parts list snippet below (from Juki TSC-441). Also note the 3/16-28 and 3/16-32 screws to drive you to the edge of insanity trying to match up threads. 15/64-28 is also dangerously close to an M6-1.0 screw. 15/64"=5.953mm, 1mm pitch is 25.4/inch. Both 1/4-28 and M6 screws will thread a few turns into an 15/64-28 threaded hole before binding.

Thanks for solving my little part mystery, @Evo160K! My part is also a SIMANCO 91436. The thumb nut threads nicely onto a 15/64"-28 bolt from my Juki parts bin.

Just click the link below to pay and then send me a PM with your postal mailing address. http://paypal.me/UweGrosse/12.00

This PDF has a somewhat comprehensive list of bobbin sizes, including Style "I" : Bobbin Selection Information.pdf You may be able find a standard style that fits your 29K60 without giving up too much thread (not a whole lot of thread to give up, for sure. ) The good folks at The Thread Exchange have various prewound bobbin styles in stock and might be able to offer advice (they also have a bobbin style guide with dimensions)

This pretty Singer NN88W thumb nut is $12 shipped. I have a few disembodied Singer 29K heads floating about in my drawers. The same thumb nut also appears on a another part, but I'm not sure which machine this part goes with.

Bump and price lowered to $1250.

A thread groove would be fairly easy to add with a small diamond file or an angle grinder. I also considered making a variation with a slightly angled/curved bottom surface to conform to the standard curved throat plate, and also one where the rear foot comes super close to the front foot with almost not gap at all. But realistically, I have to stop making changes and settle on one design at some point to start with. I'm lucky if I sell enough of these to pay for all the end mills I broke making the half dozen iterations leading up to this one.

I made a small batch (5) of my version of the inline presser foot (named UP441-ILSS) and they're now available for sale for $70 ($90 for the set) in my ebay store: http://r.ebay.com/C7t3Tt If you're located in the U.S., you can also order directly from me for a 10% discount (send me a PM to get the ball rolling) Here are a few shots of the production version:

Bumblebee and Kermit are definitely in the over-100 lbs category.

Part numbers are your key to Singer part nirvana. Surprisingly, no part list is available online for the Singer 138W101. Luckily, I have one of these machines and my bobbin case has a decipherable part number stamped on it: 241676 There's one on Ebay in the U.K for £36 - surprisingly expensive for a Singer part. College Sewing in the U.K. also carries this part new, made by Towa, for a little less: https://www.college-sewing.co.uk/store/241676=CP-51F-BOBBIN-CASE-CAP-SINGER-TOWA

I'm not aware of a list, but it would be nice to have one. Realistically, though, it's a little like asking the server to recite dozens of craft beers when all you really want is a Bud Light. That Bud Light in this context is one of well over a dozen versions of a Juki TSC-441 class machine. There are lots of other vintage brands and models out there, but few folks are willing to deal with them and even fewer are willing to write a dissertation on the topic. You could spend months coming up with a comprehensive list of vintage machines categorized by thread handling ability. I hope somebody does one day. "Heavy Stitcher" is what you are looking for. That generally also means that the machine head weighs 100 lbs or more. If by "reasonable price" you mean what a machine is actually worth, you should be golden.

I'd take it for $80. I had a curb-rescue Tacsew T1563 a while back and it came together beautifully after buying a few parts for it. Parts are readily available and generally cheap. I made a video with mine when it was done:

I got a little teary-eyed when I found several of these beautiful Adler 30-1 machines for sale on Ebay in Germany for under $400 just now (examples: http://r.ebay.com/YACnvn and http://r.ebay.com/5BFCMo ) Germany is the place to be if you're into these machines. Hopefully @Constabulary will find a suitable throat plate for you in his parts stash. The part does look rather simple to make, at least the top side looks easy. Some of these have space carved out on the underside, too, which might complicate machining one a little bit.

Thank you, @cjartist

Sunny Sewing Center has a nice image gallery of an Adler 30-1 they had for sale. It's a good reference gallery to see what things should look like. The throat plate is indeed quite different from the Singer version:

You're gonna scan that to PDF and post it here, right?

I finally got around to making a real-life version of my CAD model inline presser foot. Coincidentally I also became warden of a like-new Ferdco Super Bull 2000 with a career-ending massive crack in the casting (it fell off a moving cart years ago before ever being put to use.) The machine lets me test parts for proper fit and take pictures. Unfortunately I can't make videos of it sewing. This version is done in 304 stainless steel. It looks simple but the CNC mill labors for nearly 30 minutes on a single part. Stainless steel is really hard to work with, literally. No mounting screw yet - I'm still deciding between hole and slot. I'll have some for sale in a week or so, after some fine-tuning and polishing. Pricing will be around $70 for just the stainless steel rear foot, or $90ish for the set including the generic front blanket foot. Plain polished steel will be $20 less.