DG1

Like lots of things, the bobbin size is an engineering compromise. As the bobbin gets larger to hold more thread, the loop of thread that goes around the bobbin case will need to get larger which of course will mean the hook will need to be larger, the takeup arm, etc, essentially the machine would have to be larger/heavier. There is another consideration also: As stitches are being made, when the needle goes down thread is fed down through the eye of the needle as it goes around the bobbin and then is pulled back up through the eye of the needle to make the stitch. With a typical sized bobbin case, you can see it's quite a bit of thread, maybe several inches of thread going down and up the eye of the needle, to make one stitch that is say 1/8 of an inch in length. It's kind of hard to picture but basically you have the same segment of thread going through the eye of the needle multiple times. The bigger the bobbin case, the more times the thread will need to go through the eye of the needle, which would probably weaken or fray the thread.

Thanks! Looks like I'll stick with the leather needle. I'm using v92 bonded nylon, with a #19 leather needle on my durkopp patcher. Seems to work good.

Before getting rid of an old leather couch I salvaged lots of leather from it. Not sure of the weight of the leather but it is reasonably thin and very soft and pliable. What type of needle is typically used to sew this type of leather? I have both leather needles and regular round point. I know the leather needle should be used for veg tan leather, but what would be better for thinner pliable leather like that used to upholster a couch/chair etc. Is there a disadvantage to using a leather needle that will cut the leather? With the round point it seems like it will pierce and stretch the hole, which will then tend to close up afterwards tightening around the thread (at least that has been my experience hand sewing leather using an awl to make a hole). Thanks!

Thanks!

Hello, I'm building a table for my Durkopp cobbler/patcher machine. These originally came mounted on a cast iron base with a treadle, similar to a Singer 29. I'm going to do a bit a tinkering with different configurations, possibly a speed reducer and a basic servo motor. I don't know what length belts I'll need and may be changing them around so I'm thinking of using leather drive belt where I can customize the size as needed. If they work good I'll keep them, or eventually switch them out to a standard 3L v belt. I'm really confused as to what thickness belt to use, I'm not sure if the sizes are equivalent to a standard belt. I put a normal industrial 3l v belt on the handwheel of the machine and it fits perfect. I can get the leather belt in 1/4, 3/16, 5/16 and 3/8. What size is typically used on an industrial machine with modern servo motor/pulleys? Thanks!

https://www.facebook.com/groups/837365077098705/files/files I tried to upload these files but they where to big. The link has the manuals in both English and German. I would download the German page for the illustrations, they seem to have blurred a bit on the english version. Duerkopp_Cl_17_-_User_Manual.pdf Durkopp_17 Patcher_Manual_English.pdf

Is is possible to adjust the lash on the hook gear set on this machine?

I did adjust the foot lift (using the wingnut at the back of machine). It does not seem to make any difference. But I don't think it's that since it makes the exact noise with needle unthreaded, foot in the up position.

I have run the machine unthreaded with the presser foot up, it makes the exact same noise. After purchasing the machine, I cleaned it and thoroughly oiled directly every part reachable that moves against another part , plus all the oil holes. I've physically moved every linkage in the head and everything is tight with no play. Same with the walking foot linkages at the back of the machine. The only part that really has any play in it is the presser foot linkages at the back of the machine that go to the knee lifter, but I've held on to those while running the machine to dampen any possible vibration and it's not coming from there. I've subsequently examined the bottom of the machine more thouroughly and everything is very tight except for one thing: I noticed the gear that is attached to the hook shaft has just a tiny bit of play or backlash. I can just barely detect some rotational movement of the hook (the actual hook not the bobbin case) but it's really a tiny amount, like you can't really see it but you can feel it. I'm not sure if there is supposed to be zero backlash at that gear. If so I don't see how to take out the backlast. the gear is tight to the hook.

Hopefully this works

https://www.facebook.com/share/p/dvprqQ1uXHrFpsZZ/ Maybe this link will work

Hmm, could you try it again? I'm not super familiar with facebook, the link works for me but maybe only I was able to see it. I pressed the "share button" so maybe it will work now. I tried to post the vido here but even though it is only like 16 seconds long the file size was too long.

Hello, I recently aquired a Juki LU 562. It is sewing great but at higher speeds makes an irritating higher pitch vibrating/chattering noise as if something is loose. It's hard to tell but it appears like the noise is coming from the head area, maybe where the walking foot mechanism is at the back. I've gone over the machine and can not find anything loose. It's hard to describe the sound so I've attached a link to a video. I don't think this noise is normal. Does anyone have any suggestions on what to check? Thanks! It also makes the same noise when not sewing anything with the presser foot up. https://www.facebook.com/61560928232099/videos/513472158205034