kwalk20 Report post Posted February 11, 2016 Can anyone tell me what would cause my stitch length to change on its own? I have a Seiko STH LBD-3, basically the same machine as the Consew 206rb-5. I had my stitch length set to 5.5. Before I began I tested on scrap pieces of leather and all was fine. I notice it seems whenever I encounter a part a little thicker or that has an awkward position the machine changes stitches on it's own. It began sewing at 3 and as I continued to sew it went back to 5.5. Anyone know what happened or why? Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted February 11, 2016 (edited) If your stitch length is set by a rotary dial with detentes, the knob could be a little too loose. The shaking from higher speeds or new layers to overcome might cause the knob to leave the preset position and move one way or the other. Try finding a set screw that secures the knob onto its shaft and see if you can loosen it, push the knob closer to the body, then tighten it again. This may keep the knob and the shaft its on from turning on their own. Edited February 11, 2016 by Wizcrafts Quote Share this post Link to post Share on other sites
kwalk20 Report post Posted February 11, 2016 Why didn't I think of that?! LOL. Thank you Wizcraft. I thought it was a problem with the machine itself or the area I was sewing. I will try this. Quote Share this post Link to post Share on other sites
kwalk20 Report post Posted February 11, 2016 Could that have caused such a drastic change? Starting at a 3 to then suddenly a 5.5? Quote Share this post Link to post Share on other sites
Wizcrafts Report post Posted February 11, 2016 (edited) I just re-read you problem report. It seems that your stitch length changed when you walked up onto another layer, then returned to your preferred length once back on the original thickness. That is a whole nuther issue than I addressed. This unwanted change in stitch length with changes in thickness could be caused by an incorrectly set inside foot position in relation to the needle, or incorrect adjustment of the alternating height of the two feet. A good starting point is to remove the material and hand wheel the machine until the tip of the needle is at the height of the feed dog. Stop wheeling here. Loosen the big bolt on the mid-back of the head that controls the position of the inside foot and lower that foot to hit the feed dog with the tip of the needle. Lock down the bolt. Try sewing a sample piece. If the problem persists, try adding or subtracting pressure on the outside presser foot. This is usually done via a threaded hollow screw on top of the left end of the head, directly over the presser bar. I usually back off that spring action until it has just enough force to keep the leather/material from lifting with the ascending needle. Also, check the feed dog for free motion. It should not move from finger pressure alone. If it does some screw is not tight. There are two little screws that secure the feed dog. You have to remove the throat plate to get at them. Use a long, narrow blade screw driver to tighten them down all the way (keeping the feed dog aligned straight ahead). If those screws weren't loose and the feed dog still moves forward and backward by your finger on it, the bolts under the end of the body may be loose. You'll have to flip the machine back on its pivots to see those cranks and moving parts that move the feeder. Check the shaft that the feed arm is mounted to. It has cone shaped bolts on the left and right ends that set the position and slack. The screws should allow the shaft to move, but not so much as to be sloppy. The goal here is to have all feed parts moving smoothly, without binding and also without excess slack. Keep every moving part oiled. A properly adjusted walking foot machine won't have much difference in stitch length unless the thickness changes from one preset thickness up to 3 or 4 thicknesses. Then the pendulum* effect overrides your desired stitch length and you will have to compensate manually. But, a change of one layer shouldn't change the length that much, like you described. * The pendulum effect is the change in stitch length in a large difference in thicknesses being sewn. It is due to the fact that the needle bar is mounted at the top of the head and it swings like a pendulum as it sews forward and backward. Material that is higher up from the base level meets the needle sooner and the needle moves a shorter distance up there than it does close to the base of the machine. Edited February 11, 2016 by Wizcrafts Quote Share this post Link to post Share on other sites
