friquant

Oh I see...if you can get the correct tooth to match between the gears, you wouldn't have to loosen the bevel gears at all 😃 I want to put a mark next to my gear teeth (and between the shaft and the gear) so I can take apart and put back together the same way, without having to measure timing. But I haven't done it yet..

@Yoshi888 Excellent video! As you have already concluded, whatever is supposed to hold the (horizontal) hook driving shaft in place left-to-right has come loose, which has allowed the two bevel gears to disengage and therefore lose track of time. First you need to get the (horizontal) hook driving shaft fixed in place left to right. Then you will need to set the hook-to-needle timing. I expect you won't need to purchase any parts.

Agreed.

@Yoshi888 Can you turn the machine slowly by hand and identify what/how it is actually binding? The situation I suspect the most is that the set screws that hold the bevel gear in place (and keeps the correct timing) are loose, and the bevel gear has moved laterally away from the other bevel gear a little bit. The way to check would be to loosen the three set screws in the bevel gear and press lightly to slide the bevel gear to the left. If done carefully you may be able to do this without changing the timing much. (But if they actually are loose, then who knows how much they have already moved... Do you have a manual for this machine? I'm using this one: https://leatherworker.net/forum/applications/core/interface/file/attachment.php?id=139088 but you can probably find one in German too. Some general videos on timing: https://www.youtube.com/watch?v=1wNBPX8i524 - video by Uwe of Consew 225 https://www.youtube.com/watch?v=pL9WiZeKZAY - video by Uwe of Adler 67

I'm using this on an old singer treadle table, using the original treadle as the gas pedal. The treadle is fairly heavy. The heavy pedal, in concert with reduced spring preload on the clutch, effectively takes the brake out of the equation. Meaning the spring preload is enough to counteract the weight of the pedal, but not enough to apply the brake. (Adjusting for a large amount of freeplay between where the brake engages vs where the clutch engages also helps this work out.) That makes sense. This is a three-phase, two-pole clutch motor and I'm powering it with a variable frequency drive (VFD). The highest I ever set the VFD with this setup is 17Hz, which spins the machine head at 310 stitches per minute. At that speed, even with no brake it comes to a complete stop 1.5 revolutions after letting off the gas.

Take a look underneath at the hook driving shaft. Check if the bevel gear on the (horizontal) hook driving shaft is snugged up against the bevel gear on the (vertical) hook shaft. If there is a wide gap between the two bevel gears, I could imagine it binding up. Also verify: No missing teeth on either of those two gears. Three set screws tight on bevel gear on (horizontal) hook shaft Set screws tight on feed dog vertical movement eccentric (mounted on horizontal hook driving shaft). No interference between feed dog vertical movement eccentric and either of the bevel gears

What country are you in? You can buy machines through alibaba, but I would find out how much the import duties will be.

Have you already verified that you are using a new needle of the correct system? In my Singer 31-15 my needle looked off in the throat plate until I discovered that I was using 2mm shanked needles, and the machine actually needed 2.5mm shanks.

Once you get your allen wrench in the screw circled in red, rock it both ways. That is, attempt clockwise, then attempt counterclockwise, then clockwise, then counterclockwise. Make sure you have the correct sized allen wrench. Also make sure you are NOT using the ball end of the allen wrench (if your wrenches have that), as the ball end only provides a small contact patch.

Do you have anything stronger? Are you saying it's a hex type, like allen wrench? Is there a lock screw holding it in place, by any chance? Can you send a photo?

I would love to have a cowboy cb3200, but it's too big to work gracefully on thinner projects like wallets. From the specs page it says the needle system is 7x3 or 794. These are very long needles, and you cannot buy thin needles in this system that have a leather point. Furthermore, when you run a thin needle with that length, they are prone to bending. Note @Wizcrafts does suggest the cb3200 in his blog on dumbing down a 441. But in general, for stitching thin to medium materials (1/8" to 1/2" total) I recommend getting a machine that takes the most common needle size, 135x16. Only in part because the needles are easy to come by in different sizes and tip shapes, but largely because the 135x16 is short enough that it does not bend easily like the system 190 or especially the system 7x3 / 7x4 / 794. Here is a photo to show the two needle systems. On top is a system 7x3, size 180Nm. On bottom is a system 135x17, size 135Nm. By the way: 135x16 is the leather-point version of the 135x17 7x4 aka 794 is the leather-point version of the 7x3

A couple drops of diesel fuel, left to sit a couple hours. That's what I use. And make sure you have a screwdriver that is a good fit for the screw. I've been using this "sewing machine" set made by Chapman. It comes with several different sized hollow-ground (paralled-sided) bits and a mini ratchet to give extra torque. Here's the amazon link where I purchased for $55.

Which direction is your bobbin inserted? Here is a screenshot of the pfaff 335 manual showing the correct orientation. If inserted the opposite direction, the thread can slide out of the bobbin tensioner, which is bad.

Does it jump to the middle when going in reverse? After it jumps to the middle, does it ever revert to its former position? When the lower thread is in the middle, does it interfere with the top thread clearing the bobbin case latch?

Are you having trouble getting the machine to stitch properly, or are you asking about the fundamentals of how a sewing machine forms stitches? If the former, I suggest making a close-up video with the bobbin cover removed, while you turn the hand wheel VERY slowly and smoothly. Here is a great example of such a video:

I would look at cylinder arm machines. The cylinder arm gives the versatility to sew 3-dimensional shapes, including the gussets on purses and bags. We're talking machines like the Juki 246, Juki (1)341, the Pfaff 335, or one of several clones of any of these machines. In terms of needle systems, I would target a machine that uses the most common needle system, which is 135x16.

I was wrong about this. I didn't realize that the 211G does not actually have a stock handwheel screw. I assume that piece with the triangle is actually the arm shaft.

What are the remaining questions on this topic? Have you made progress? Are you still waiting on a part before proceeding?

You'll need to decide what thread size you want, and then get needles big enough for the thread and material. See AlZilla's links:

I haven't found many parts on a sewing machine that bend. That is, most parts on my sewing machines seem to be a very hard material that is likely to have fracture as its failure mechanism, not plastic deformation.

An internet search for juki 243 parts manual led to this: https://www.jukisewingmachines.co.uk/pub/media/productfileupload/j/u/juki_tnu243_parts_book.pdf On pages 11 and 12 shows the hook driving shaft (part #10), the left end of which is the shuttle driver.

Maybe 3D print

Here a link to a manual for a Juki 243: https://www.manualslib.com/manual/1638502/Juki-Tnu-243.html Section 21 (pages 10 and 11) discusses adjusting the feed dog to needle relationship.

Yes, the part in your hand is the needle position sensor. Check if your hardware kit comes with a collar and extra long screw like this: If it does, remove the stock handwheel screw, and install the collar (with extra long screw) in its place. Then the needle positioner fits around the provided collar instead of around the shoulder of the actual handwheel.