Lucasn7

That worked. Thanks to all of you who replied!

Indeed! It worked! I've moved the left assembly enough so that there is the same space between both needles and hooks. Now the next problem. I can feel (and hear) a bit more play in the gears of the left hook. I've moved the assembly to the left so there is more space between the angular gears. I've tried to loosen the screws on the left gear and gently tap it to the left but it won't move a bit. Any suggestions? Forward thanks!

Good suggestion. I've cheched the original manual but i did not find how to change it. It tells me how to change the needle but not how to account for a different spacing.

Hi! Thanks for your reply, i have not looked at leatherworker eversince and now i have a few replys :). I already loosend and removed the screws but the left hook assembly is still rock solid. I thought maybe there will be some more screws i'm missing.

Help is still welcome

Hi, i own a Pfaff 346-H3, the double needle version of the Pfaff 335. I have this problem where the left needle scrapes the ring of the left bobbin assembly. When that happens the thread and/or needle breaks. Usually i only sew with te right needle but at this moment i'm working on a workpiece that is to large to fit under the arm. On closer inspection you can see that the left bobbin case assembly is closer to the feed dog than the right case assembly. Also you can see needle scraping marks on the assembly. I've loosend all the screws i saw but still it cannot move. I have loosened all the related screws I saw, but there is no movement yet. Does anybody have experience with this? Forward thanks!

Hi it's been some time since i replied to this thread because i was busy and after that i've only used the right needle. At this moment i'm making a bag and need to use the left needle again because the workpiece can't fit onder the arm properly.. If i use the left needle the thread or needle breaks in a few stitches. How does this work? I cannot figure it out. Also the machine looks like the whole hook assembly can be moved? Forward thanks

Indeed i've noticed the tracks and slots but never knew they were for moving the hook drives. When i look closely i can see that the left bobbin assembly (scraping one) is a bit closer to the feed dog than te right one (second image). I've unscrewed the big screws in the slots and also on a block on the bottom side that looks like it needs to be moved in order to make room. But still i cannot move the hook drive. Also i'm a bit afraid to mess up the timing when adjusting the driving gear by loosen and fasten it... Any thoughts? Regards!

I threaded the machine according to the official user manual so that should not be causing any problems. The take up spring might be to taut because it is made (and adjusted) to be pulled by two threads at the same time for both needles. I've adjusted the spring and i'll keep experimenting.

Aah i see, well spotted. Indeed, in the video i was not using the thread guide. Normally do use it but when this problem that occurred the thread snapped a lot so i took a shortcut. See attachment.

Indeed i saw the yellow thing when i uploaded the vid. It is tape in an attempt to make less marks on the leather, a temporary solution.. In a future project i'll investigate if i can buy a new pressor foot/ grind the teeth or CNC one myself.. Indeed i was missing my throat plate, thanks for pointing out. Furthermore the machine is working except from the scraping sound (see post above) but that is not because i'm missing parts. As far as i know i'm not missing any parts. I have a double needle machine so the second hole is for the second needle i did not install at the moment. For as far as i know it is a double needle version of the Pfaff 335 series and threads the same. Thanks for your replies!

Hi, thanks for pointing out that the bobbins are rotating because of the missing throat plate! Now i see, indeed there is a slot that matches the rotating part. Actually i was disassembling my machine because the left needle made a bit of a scraping noise and sometimes broke the upper thread. I removed the plate to see inside and indeed i saw the needle scraping the GIB. Also i can see small marks on the GIB where the needle touched. After this discovery i tried my machine (handcranked) again and then the above happend… For the scraping: i’ve tried different needles and only my thinner needles (size 80/12) do not scrape compared to the normal size i use. According to the manual size 130/21 should be okay. Any ideas for this? Also thanks for linking the instruction manual. i did not find that one online. Regards!

Hi, recently i bought a Pfaff 345-3H (i’m not 100% sure but it looks like a double needle version of the Pfaff 335) and it worked fine. I’ve done a few projects with it and so far no problems. I did not do anything in particular for as far as i can remember but now both bobbins are rotating and skipping stitches(i guess there is not anything broken with one because both have the same issue). I’ll try to explain what is happening but please see video link below. The loop of thread around the bobbin gets stuck between the bobbin case and the thing that keeps the bobbin from rotating (i don’t know how this part is called). The thread loop stops and gets pulled trough with a click. It looks like that is causing the skipped stitches. Sometimes the whole bobbin case gets pulled with the threat and the case makes a full turn and gets tied up. According to the video in this thread i found https://leatherworker.net/forum/topic/85248-please-help-thread-is-too-tight-when-pass-bobbin/ the bobbin case should not be rotating and the stoppy thing opens and closes in the right time to let the thread pass. I’m not very experienced with leather sewing machines but i searched a lot and could not find a solution. At this point i’m not even sure if the bobbin is supposed to be moving or not... Any ideas on what causes this and how to fix this? Forward thanks! Video of the problem: