I need help with a Consew

[williaty]

This isn't leather related but this subforum is the best (and really only) place on the internet for technical discussions about industrial machines of all kinds. I'm hoping the community and mods are willing to roll with me here.

I have a Craigslist rescue Consew 395f Subclass 757F-516M2-35 overlocker. The machine is actually made by Siruba and they call it a 700f with the same Subclass number applying. I've got it cleaned up, threaded, and mostly working now. It stitches properly but it feeds the fabric EXTREMELY crooked. It pulls the fabric into the machine/knife (to the right from operator's position) aggressively. To feed roughly straight, I have to hold the incoming fabric about 35 degrees off to the left. It's actually bad enough that the edge of the stitch looks a little rough because it sheered sideways enough after the knife to push the fabric through the looper threads. I don't know if it's related, but it really mangles fairly lightweight fabrics like the cheap muslin I use for making toiles and for general testing. It's fine with slightly heavier fabrics like coarsely woven cottons. I initially just assumed it was because this is listed as a medium-weight machine but I don't know if it's another symptom of whatever is making it feed crooked

 

Any idea why this would be feeding so crooked?  I want to get this issue resolved before I deal with the major problem which is that it has a big oil leak. If I can't sew well with it, there's no point in trying to find the leak.

[trash treasure]

I don't know if I can help, as I'm not familiar with that model -

Does your machine have a differential feed, and if so, have you tried adjusting it to see if it changes the issue?  Are the knives sharp and set right (Lower one even with the needle plate)?  Feed dogs tight & level with needle plate? Presser foot down all the way  and set correctly? Are the loopers clear, and not jammed up with trimmings ? One or more tensions way out of whack ?

A lot of things to cause problems with a serger - Start with fresh sharp knives, first, and a different color thread in every spool.

 

[williaty]

23 hours ago, trash treasure said:

I don't know if I can help, as I'm not familiar with that model -

Does your machine have a differential feed, and if so, have you tried adjusting it to see if it changes the issue?  Are the knives sharp and set right (Lower one even with the needle plate)?  Feed dogs tight & level with needle plate? Presser foot down all the way  and set correctly? Are the loopers clear, and not jammed up with trimmings ? One or more tensions way out of whack ?

A lot of things to cause problems with a serger - Start with fresh sharp knives, first, and a different color thread in every spool.

 

Thanks for getting back to me. My current suspicion is the knife as there's some raggedness to the cut edge. I've ordered a knife set but it's on a slow boat from China. A *very* slow boat these days.

[DrmCa]

Post pictures of the machine and the problem.

[williaty]

After waiting on the slow boat from China, I got the blades in and of course they didn't fit even though they were supposed to be direct replacements. A few minutes on the grindstone got them reshaped to fit into the machine. That seems to have been the only problem. With sharp blades, the machine now feeds straight.