Top and bottom mechanism timing on Pfaff 145

[Marcremb]

Hello. the top thread on my Pfaff 145 h3 is to tight . I mean when it turns around the hook, like if the take up lever would lift the thread to soon during the cycle.

I hook timed it correctly (0 feed, 1.6mm rise and hook in center of needle and scarf) but May be the top and bottom mechanism timing is not correct. I can't find any information on this pfaff 145. Does someone knows something about it? 

Thanks 

Edited October 11, 2023 by Marcremb

[Northmount]

5 hours ago, Marcremb said:

Hello. the top thread on my Pfaff 145 h3 is to tight . I mean when it turns around the hook, like if the take up lever would lift the thread to soon during the cycle.

Moved your post to leather sewing machines.  This is where the sewing machine guys hang out and you are most likely to find the answers you are looking for.

[Wizcrafts]

6 hours ago, Marcremb said:

Hello. the top thread on my Pfaff 145 h3 is to tight . I mean when it turns around the hook, like if the take up lever would lift the thread to soon during the cycle.

In my experience, when the top thread is so tight that it snaps going around the hook, the timing is retarded. There's two ways to correct this. One is to advance the hook. The other is to adjust the check spring for more slack during the take-up cycle. The additional slack is normally used when sewing thick seams, or if the material is bunching up from too tight stitches. If your hook is slightly slow, the check spring adjustment might reduce the tension going around it. If not, advance the hook slightly.

It's possible that the hook has too much slack in the gears so that even though you timed it correctly at rest, it retards during operation. It might even have one or both set screws loose. Or, it could be set too high in the saddle, or the slack gears might allow it to lift during take-up..

[fibersport]

If you do a google search for "pfaff 1245 adjustment manual" you will find a link to a section on the pfaff site https://www.pfaff-industrial.com/db-downloads/technicaldoc/justieranleitungen/1200/ja_1245_1246_10-15_en.pdf/@@download/file/JA_1245_1246_10-15_EN.pdf that has the manual.  I know it's for the newer 1245 but I used it to adjust my 145 and 545.  Follow the steps in order and you should solve your problem.  

[Marcremb]

4 hours ago, Wizcrafts said:

In my experience, when the top thread is so tight that it snaps going around the hook, the timing is retarded. There's two ways to correct this. One is to advance the hook. The other is to adjust the check spring for more slack during the take-up cycle. The additional slack is normally used when sewing thick seams, or if the material is bunching up from too tight stitches. If your hook is slightly slow, the check spring adjustment might reduce the tension going around it. If not, advance the hook slightly.

It's possible that the hook has too much slack in the gears so that even though you timed it correctly at rest, it retards during operation. It might even have one or both set screws loose. Or, it could be set too high in the saddle, or the slack gears might allow it to lift during take-up..

Thanks Wiz. I will try those possibilities. 

1 hour ago, fibersport said:

If you do a google search for "pfaff 1245 adjustment manual" you will find a link to a section on the pfaff site https://www.pfaff-industrial.com/db-downloads/technicaldoc/justieranleitungen/1200/ja_1245_1246_10-15_en.pdf/@@download/file/JA_1245_1246_10-15_EN.pdf that has the manual.  I know it's for the newer 1245 but I used it to adjust my 145 and 545.  Follow the steps in order and you should solve your problem.  

Thanks Fiber