Stitch Quality Problems and Fixes
Checking and Setting Your Gammill Needle Bar Height
Occasionally skipped stitches are caused because the needle bar has been knocked out of position by heavy silk screens, thick seams, hitting something like a pin (or worse, scissors). Make sure the needle is properly seated by looking in the small hole on the side of the needlebar, then check the position of the needle bar with this document: Checking-and-setting-your-needle-bar-height. This should always be done prior to touching your timing! Call us if you have questions!
Repairing or Replacing your Front Tension Assembly on your Gammill
Did you know that there are two ways the front tension assembly affect your tension? The resistance on the windowed wheel is affected by the white knob, but there is a separate amount of tension created by the check spring tension. You might find a few helpful hints and feel more comfortable making the adjustments after viewing this video. For an extra front tension assembly, click here or you can purchase felt pads, a check spring, or a lightweight cone spring. We always prefer the light weight spring as it enables you to have finer control over the tension.
Skipped Stitches: How to determine the cause and fix
Q: I’m getting skipped stitches on my Gammill. What can be wrong with my machine?A: Before being able to resolve this, you need to answer a few other questions:1. Is this happening while you’re in regulated mode doing free motion with the belts dropped (Statler).2. Is it only on horizontal lines, or on vertical lines?3. Are there needle penetrations, but the stitch does not form, or does the needle hesitate and not go into the fabric?4. Have you recently completed a quilt with thick seams or silkscreens (Tshirt quilt), or did you hit a pin or other hard object?5. Did you just change the needle?If you’re in regulated mode, and the stitches are skipping in only one direction (vertical or horizontal) you have a cracked or missing encoder. If they’re skipping vertically, it’s the encoder of your Y axis, located on the crosstrack near the back right handle. If it’s horizontal, it’s your X encoder, located against the long back table track or on older machines, it rides on top of the back right wheel of the cross track. Carefully replace it, as you don’t want to bend the shaft of the encoder. To replace it on the older machines, it is best to prop the crosstrack up on some books and remove the outer wheel to access the encoder. DO NOT force it down past the wheel or you’ll damage it. There is more about encoder rings in one of my previous blogs.If you are skipping in both directions with needle penetrations, and you’re recently changed your needle, the needle might not be properly seated. There is a small hole opposite the needle set screw that you can look in – make sure the needle is seated all the way in the needle bar. Also, if you’ve switched to a thinner needle, your needle might be flexing away from the hook while the machine is traveling. I recommend sticking with size 4 needles (18s) as this is what the machines are generally timed to.If your belts are attached and you are in computerized mode, and it’s skipping WITH stitch penetrations, your needle bar might have been jarred out of place by stitching multiple seams or hitting something, or Tshirt quilts with lots of thick silk screens can knock it out of position. You’ll need to adjust your needle bar height. For information about how to check this and make an adjustment, click here.If the needle is hesitating and not penetrating, it’s skipping stitches in both directions and your needle bar is in the correct place with the needle properly seated, your motor belt may be slipping or need replacement. The tension on it will need to be properly adjusted by raising the motor slightly. Do not over tighten the belt.
Whatever you do, don’t assume that the timing is off. Chances are great that it’s one of the above issues and the timing rarely go out – the last thing you should do is attempt to retime the machine, so for the sake of your own sanity, step away from the screwdriver!
Stitch Quality: Loops on the Back of the Quilt
Q: What causes big loops of top thread on the back of the quilt?A: If you’re seeing this, it’s helpful to know what the size of the loops are – I’m guessing they’re around ½” of thread, and are pretty consistent. Most people would blame the bobbin, which is not the case in this situation. A badly wound bobbin, bad antibacklash spring, or using a bobbin genie would not cause or fix this issue. You’re seeing excess top thread, not bobbin thread.If the loops are a little larger than ½” of top thread, the rocking finger might be the cause. Before you do so much as one more thing, power down the machine!!! The safest thing would be to actually unplug the machine.Hold the top and bottom threads at a 9:00 position on the needle plate. Track down your bifocals and look in the hook area. Hand walk the hand wheel around (turn it clockwise) while watching the thread move across the face of the bobbin case. If it snags on the rocking finger (the small finger located at a 6:00 position that taps a little tab on the hook assembly), you’ve got your answer. It’s possible the rocking finger was bumped and is not properly positioned/timed. I’ll talk about how to fix this in a later blog post.If the thread easily slips past this area, you’ll need to take off the needle plate to check the next probable cause. This is a good opportunity to get out your vacuum and a brush and do a little housekeeping. Note: I DO NOT recommend canned air!After removing the four pounds of tightly packed oil soaked lint found in many machines, again hold the threads as discussed above at exactly an 8:30 to 9:00 position. Hand walk the wheel. As the thread travels around the front of the face of the bobbin case, watch carefully as it clears the small gap between the retaining bracket and the notch in the hook assembly at the 12:00 position. The retaining bracket is black. The small protrusion of the bracket that fits into the notch on the hook assembly should be in about 1/3 to 1/2 of the depth of the notch. If the thread is catching here, the retaining bracket is in too far for one of two reasons: it was bumped and pushed in (perhaps because it was not properly tightened down), or for some reason the hook is further forward than it should be, which will cause the needle to be pushed forward as the hook passes behind the scarf of the needle.If the timing is OK (the needle is not being deflected forward at all), then the retaining bracket needs to be adjusted.Grab a flashlight and either a good screwdriver or your metric Allen wrenches (depending on machine age). If you look from the floor up into the bobbin area, you’ll see where this bracket is screwed in. Loosen the screw, reposition the bracket and TIGHTEN the bracket in place. This could be a two person job. You DO NOT want this to move ever again as it can be pushed out and really cause some damage as the entire hook assembly spins out of control. Test again by hand walking the wheel while watching several rotations. If you are confident that everything is OK, replace the needle plate and put all four screws in loosely. Again, hand walk the wheel until the needle is in the lowest position. Center the hole of the needleplate around the needle, then tighten the screws down. Test the stitch quality to make sure the problem is resolved!
Gammill Stitch Quality Issues Q and A: Encoder O Rings
Q: My regulated machine is working fine stitching side to side, but when I move it vertically it hesitates and forms large stitches, or won’t stitch at all. What’s wrong?A: The good news is that this is one of the easiest fixes there is! On your machine are two little rubber O rings that are on encoders, which tell your computer where the machine is and how fast it is moving, and ultimately determine stitch length. One of these encoders (Y Encoder, dictates vertical stitching and the culprit in your case) sits on the cross track:Above is the Y Encoder on a Vision (regulated) machine.The image above shows the Y Encoder on a older Plus (Regulated) machine.The other (X Encoder, dictates horizontal stitches) is on the back and is positioned either on top of the back right wheel or travels along the long track of the table.These $2 parts are responsible for accurate stitch length. Because they are rubber, they are subject to cracking over time, especially if your pot belly stove is near your machine or sun beats in your uninsulated window, shining right on the encoder. Actually, the dry conditions of this region are also hard on these.You’ll want to have some extras on hand in case cracks do develop. Carefully remove the old one (if it didn’t fall off and get sucked up in the vacuum) and gently roll the new one in place, and bam, you’re back in business.A word of caution: you can bend the center post on these with excessive force. The O ring is cheap, a replacement encoder is not! Both encoders are pretty accessible on Visions. On older Plus machines, the X Encoder is harder to get to. Prop up the back end of the crosstrack with a 2×4 or several books, and remove the back right wheel to get to it. DO NOT pry it down past the wheel or you might be purchasing a new encoder! Replace it, push it up into position and then replace the wheel.On Statlers, older machines have metal encoders that ride on a serrated track on the crosstrack, and there is a third long stretch of belt on the front of the machine that rides on an encoder. These don’t tend to have issues. Newer Statlers (2007 or so and later) have the same encoders that the Plus or Vision has (see above).On Statlers, these are secondary encoders. The belts themselves are the primary encoders, and provide information about stitch length while the belts are engaged. It’s only when the belts are dropped and you are in regulated free motion mode that the rubber O ring secondary encoders are providing information to the computer. If you never drop the belts, you might be in for a surprise as the O ring may have disintegrated years ago!To order new encoder O rings, click here. If the O rings look perfect, check the plugs going into the encoders and the ones on the back of the machine.
Why is Glide thread popping out of the intermittent tension assembly?
Common question! Start at the spool and work forward. Put on an appropriate thread net, but only around the bottom 1/2″ of the spool. That’s right – I don’t let it come into contact with the thread because it can increase tension. I just want it around the plastic rim that makes up the bottom of the spool, which will prevent the thread from catching on a little notch the manufacturer has on this rim to help store the thread end when the thread isn’t being used. Tuck the rest of the net up into the spool and put it on the machine.Also, make sure your thread spool is perfectly lined up with the take-up guide above it. If it isn’t completely aligned, the thread will drag on one side of the spool, causing a rubber band effect that can make the thread pop out of guides or tension devices.Next, feel for burrs in the thread path that might be snagging the thread before it gets to the intermittent tension assembly (ITA).The guide just in front of the ITA should be in a 3:00 position. Make sure you’ve threaded through it, around the bottom clockwise, then through it again. This will help the thread stay in place.Finally, is the ITA too tight? Seems like you should tighten in down, but the opposite is true. Try loosening it. If the discs are too tight, it will actually push the thread out of the device.
What causes stitch problems when stitching over fused areas of a quilt?
This could be caused by the brand/type of fusible, but you might also need to check the timing. If there is contact between the needle and the hook, it can warm your needle slightly (or even sometimes enough to burn your fingers), causing the needle to heat up and melt the fusible, gob up the needle and cause skipped stitches and breaks. Try slowing the machine way down, and check if you using a 4.0 (18) needle with your longarm. Also, use a needle alignment magnet and make sure the needle is in perfectly straight.You can check the timing by taking your needle plate off and hand turning the wheel while looking down the side/tip of the needle. Does the needle tip flex forward at all when the hook comes past it? If it does flex, your timing needs to be adjusted. We’ll be posting videos about this soon.If the timing looks good, it just might be a no-sew type fusible, and you may not be able to stitch over it no matter what you try. Make sure when you put the plate back on, you drop the needle (hand wheel) in the hole and center the plate before tightening it back down.
- So, the best fusible we’ve found? I only use Heat and Bond Lite, and have had no issues, even when stitching through five layers of batiks and three layers of fusible (even using Bottom Line thread, top and bottom, no less!). I’ve tried a more expensive brand, but found the edges frayed over time, so go back to my Heat and Bond Lite. We recommend it to customers, and if they do bring in a quilt made with something else, we let them know that it may not be stitchable.
How to use the Jukebox Tension Test
- Place a scrap piece of fabric on the side of the loaded quilt top on the excess batting and backing. Baste this in place and create a boundary (pushpins) around it so that you can place the pattern in the boundary on your screen.
- Use the threads you’re using on the quilt, or change to a different colored bobbin to really fine tune. Run the test and inspect it on the quilt top and back. Run the test a second time with the actual threads you’re using.
- The test is designed so that the outline of the rectangle stitches first, then additional quilting stitches inside the rectangle that has some curves and sharp angles in it. Tension issues show on these areas the most. After that, the original box is stitched again.
- Run the first one to check your tension. If you’re having problems you might want to run the one with the martini glass!
Here are a few of the most common issues:
- • If you see bobbin thread pulling to the top of the quilt in corners: your top tension is too tight, or the check spring may have too much tension, or the bobbin is too loose.
- • Loose top stitches: tighten your top tension.
- • Flat lining on the back: tighten your top tension and check bobbin case for lint, especially under the antibacklash spring. You may also need to loosen the bobbin case tension and/or test it in a Towa Gauge.
- • Railroading on the back: you’re out of a tension disc or device on the top thread path, your check spring has no tension or is broken off, or the top tension is way too loose. Rethread your machine, and tighten the top tension if necessary.
- • If your second pass at the box is outside the first, your top and bottom tension are too tight and there is too much shrinkage. For other stitch quality issues, see our website for more information, or give us a call and we can help you troubleshoot!
Click here to download Free Tension Check set