williaty Report post Posted January 7, 2022 I just bought a Consew 99 zig-zag machine. In a brief test at the seller's, it sewed without a hitch. Of course, now that I have it in the shop, it's refusing to behave itself. There's almost no information online about the Consew 99, so I'm having trouble even figuring out what I need to inspect/verify with it. Here's what I've been able to determine so far. 1) The wider the zig I try to zag, the more stitches it'll skip. It seems to have to problem straight stitching and no problem with very narrow (2-3mm) ZZ. By the time you adjust it up to max width, it's often skipping 80% of the stitches on one side. 2) The smaller the thread, the more likely it is to skip stitches. It's terrible with Tex30 thread. It's only very bad with Tex70 thread. 3) The smaller the needle, the more likely it is to skip stitches. When I tried the Tex30 thread with oversized needles, it got a little better 4) The higher the top tension, the more stitches it skips. It was pulling the top thread to the back so I increased the top tension, which made it skip like mad. I lowered the top tension and then pulled the bobbin case out and lowered the bottom tension and the stitch balance improved (though not perfect) without causing more skipping. However, by the time I got it more balanced the overall tension seemed really low. 5) This one I'm not 100% sure about. There's so many other things going on that I'm not sure I'm really seeing this but... I think the tension balance on the left half of the zig is not the same as on the right half of the zig. The best balance I achieved had it setting the knots properly on one side but still pulling the top thread into loops on the bottom on the other side. Does anyone have reference material for getting a Consew 99 to stitch reliably? Bonus points for videos but even just a service document with clearances to check and stuff would be helpful. Quote Share this post Link to post Share on other sites
DrmCa Report post Posted January 7, 2022 There was a thread on it a while ago: Quote Share this post Link to post Share on other sites
williaty Report post Posted January 8, 2022 2 hours ago, DrmCa said: There was a thread on it a while ago: How similar are the 99 and 199 though? I've run into trouble assuming similarities before (with a different machine). Quote Share this post Link to post Share on other sites
williaty Report post Posted January 9, 2022 I found that the Consew 99 manual includes hook timing information but it's buried in the back of the book past the section that only applies to the model 103 so I had never noticed it. The hook timing is bang-on correct, according to the manual. I verified the "straight stitch" control position produced minimum needle swing (it did, about 0.003"). I verified the straight stitch position placed the needle in the center of the needle plate opening. I verified that at maximum needle swing, the zig and zag were symmetrical about the center. I made a timing mark 3/32" up from BDC and the hook arrived EXACTLY dead center on the needle at that amount of rise. So the timing is spot on according to the book. Looking at it carefully, in the extreme right position the hook passes the needle right at the extreme top of the scarf. In the extreme left position, the hook passes the needle right at the extreme bottom of the scarf. So the ZZ movement is using the full height of the scarf and is balanced within the scarf. One thing did bother me though: at the extreme right position, the needle bar had almost zero rise before the hook passed the needle. I mean I almost couldn't even see any movement of the needle. Since the machine is reliably making stitches on the center and left sides of the ZZ swing and missing on the right, I figured maybe the needle wasn't rising enough to form a loop for the hook to catch by the time the hook was passing the needle. I decided to retard the hook timing slightly, assuming that this would give the stitches on the right better odds of being formed even if it might mean I began to skip stitches on the left side. Retarding the hook to give more movement for loop formation actually made it skip right side stitches even worse! What on earth is going on here? Quote Share this post Link to post Share on other sites
DrmCa Report post Posted January 9, 2022 Post pictures? Quote Share this post Link to post Share on other sites
williaty Report post Posted January 10, 2022 14 hours ago, DrmCa said: Post pictures? Sure, what would you like to see? Quote Share this post Link to post Share on other sites
