Pfaff Quilt Expression 720 Skipped Stitches
 

Hi All--I have a "new to me" Pfaff Quilt Expression 720. I'm told it has about 6 months use prior to me so relatively new. After exploring all the various stitches and functions I decided to try some straight stitch quilting on a baby quilt. Pieced with Art Gallery fabric, Warm and White batting and Art Gallery fabric backing. I made a new bobbin (using the Pfaff bobbin) with my King Tut 40 wt thread, inserted a new 90/14 needle and took off--only to have skipped stitches immediately within the first 3 inches of sewing! :( I've completely rethreaded the machine multiple times and changed the needle thinking maybe I had an imperfect one out of the package, lowered the foot pressure--all with the same results. It sews beautifully on two pieces of fabric with no batting. So it either doesn't like my quilt sandwich or this operator has alot of error! :) Any and all thoughts appreciated!!

Try a 16 needle. Most of the time this worked for me, when I was quilting on my DSM.
Another thought is you will get skipped stitches if you're moving the quilt sandwich too fast. The needle will bend ever so slightly as you're moving the sandwich, and will miss the hook. You can stitch slower, but a larger needle will also help with this because it will be a little stiffer.

Thanks Peggi--I will give both of those a try! That makes sense--I wasn't sewing fast but I certainly may have inadvertently been moving the sandwich too fast in an effort to manage the bulk--and I certainly didn't think about the needle! Great lesson today not only for this machine but for all others!

I mostly FMQ on my DSM and I always use a size 16 needle. No thread breakage or other issues.

Sorry for your problem, I wonder if the 40 wt is too thick for the bobbin tension? I usually use a 50 wt in my machines, but they are not Pfaff

You may find some help for your problem at www.sewingmastery.com. She does videos of Pfaff machines and she has the QE 720 on the site. She literally will post a video for every part of the manual starting with unpacking. I have a Performance 5.0 and refer to the videos for the Performance 5.2 as they are basically the same machine.

Thank you thimblebug6000--it may be. I plan to try a smaller testing quilt and see if it makes any difference. I normally sew with 50 and quilt with 40--it might just not like the 40!!

Thank you Three Dog Night! Yes--I love those videos! I haven't found a solution to my issue yet but I am going to keep looking!

There's lots of variation in needle types. Switching to a larger needle may not help. A lot of us use "top-stitch" needles in the appropriate size. They have a longer and bigger eye than a "universal" or any other. This allows for longer dwell in the thread underneath. The little extra lag gives the hook a better chance.

Then there's "timing." Likely what's happening is you attempt to move the fabric before the needle has cleared. The needle bends and the hook misses the loop. The larger needle will help some, but practice works best. FWIW- I consider 100-16 (top-stitch) to be a minimum for any quilt sandwich.

Did you get to the bottom of this at all? I’m having the same issue. For the first 4months it was fine and now skips stitches… but I’ve realised it’s after you use the thread cutter on the machine. Sewing when the bobbin thread is up it’s fine but using the thread cutter and then that’s it skipped stitches from 4-10 skipped stitches as it can’t find to bobbin thread I assume. Is yours after using the cutter by any chance?

I have the predecessor to this machine, the Pfaff Performance 5.2. It sewed beautifully at first. Suddenly I couldn't FMQ on it, nothing but skipped stitches, very jerky trying to move the fabric. I have been FMQing many years, absolutely no problems with basic meandering stitches on my other machines, it was like something was holding the fabric making it very difficult to move smoothly. I examined, looked and looked again at all of my settings, thread, needle, cleaning any lint from the machine, had the machine serviced, etc. Thread cutter either didn't work at all or would only cut the top thread. I was even having trouble with some of the decorative stitches. Finally took it into the shop I bought it from, to see what it was I was doing wrong. Set up the machine, and it worked just fine there. Sales person, who loves Pfaff and knows them in and out, said I wasn't doing anything wrong. Took it back home, a few inches of okay stitching, then nothing but skipped stitches.

Posted on Sewing Pattern Review. Someone there suggested I might try plugging it into a UPS unit (Uninterruptible Power Supply - sort of like a surge protector on steroids - evens out high/low electrical surges/power). I was already using a surge protector, but I went ahead and picked up a UPS unit. I was stunned that it worked. Stitching worked, thread cutter worked. Fast forward several months, once again I started having issues. Again took it into the store, again it worked fine there. My UPS was showing as working (green light). I picked up another one in case it really wasn't working. Still issues. Then I altered my method. I like to start off slow, and I can do that on my other machine. What I found is that does not work as well for the Pfaff machine. A bit more speed works better. Going slow is very jerky. I can get reasonable stitches on the machine, but I don't like the machine. For FMQing at least. It still will not cut the bobbin thread, but only when in FMQing mode. Most of the time I can FMQ on it without all of the skipped stitches, every now and again that is all I get. I live in an older house, so I am sure the problem is largely due to electrical current that is not constant. A small part of it is, I think, altering my method on this machine. I finally decided that I hate FMQing on this machine and I won't be using it for that, which is a shame because that is one of the main reasons I got it. It was sucking all of the joy out of FMQing as I was spending all of my time trying to tweak the settings and alter how I do things. It and I just don't click on that front.

Perhaps a UPS unit might solve your issues. Worth a try if nothing else is working. Are you able to take it back to the shop where you bought it and try it out? It was very eye opening to have the machine work correctly at the shop when it gave me nothing but grief at home. It didn't have the jerkiness at the shop either. Actually it wasn't half bad at the shop. Even when I get it to work right at home, it is still more difficult than at the shop. I think the computer board is very sensitive to slight fluctuations in power. Perhaps someday I will be in a different house that doesn't have older wiring and we can be friends (for FMQing that is).

My original machine already went back to the shop for the same issue and then off to Pfaff. The shop said the issue still hadn’t been resolved but would send me a new machine. Well… I unpacked the machine at the weekend and it’s a ‘new to me’ machine by the looks of it. There was no lint in it at all but it had been out of the box for sure. I started sewing and straight away the same issue. It’s only after the thread cutter is used though. Doing a leader or just pulling up the bobbin thread first it’s fine. But cut the thread by the machines thread cutter and 8 out of 10 times the bobbin thread is no where to be seen for either the first 4-8 stitches if at all. You then have to rethread the bobbin as it’s too short and will not catch.

I just feel so deflated. I’m not in a good place at the moment so I’m not up for the job of arguing/confrontation. Nothing is never easy is it (sad face)

That is so frustrating. These are not inexpensive machines! I am sorry you are having this issue. Sounds slightly different than what I experienced. I felt very deflated as well, as this was more than I ever thought I would spend on a machine (it was a closeout, so a bit above my budget at the time - but definitely less than what it sold for used). I have thought about selling the machine. In the right house (with updated electrical) - I think it would be a very nice machine. I do like other things about it, really like the IDT. It was the FMQing that I really wanted to be able to use it for though. Since Pfaff sent you a "new" machine, it would seem that they are aware of the problem, because it seems these vendors never want to do that! They should be honest though if they are sending you a refurbished or a demo machine. I hope you are able to get a resolution.

#1, there are different types of UPS power supplies. Not all smooth out the power variation (most don't). The type that do are expensive - basically they don't simply pass power; they charge up a battery in the UPS then invert the DC battery power to AC line voltage. These are called "double conversion" UPS units. Line interactive also do some level of power conditioning/leveling, but only at the extremes.

#2, if you are having "dirty" power, your utility may be able to put a monitor on it to see what's going on. It could be a poorly bonded connection in one of their boxes causing the problem. This is worth asking about especially because "dirty" power can damage other things - HVAC, refrigerator compressors, etc.

#3, it could also be a poorly designed power supply board in the machine itself. In this case, unless you can smooth out the power variation, you will always be fighting poor design.

#4, your house wiring design could be a problem. If things with motors are on the same circuit as the machine, they could cause noise or voltage droop/spike. Try not to have items with computer boards on the same circuit as a refrigerator or freezer or similar items (in newer construction, those items usually have dedicated circuits as required by code).

I have the Pfaff QE4.2. I haven’t a clue how it compares to your model, but I had similar problems when first FMQ’ing.

I now use a 90/14 topstitch needle and aurifil thread. I also only FMQ with a westalee ruler foot, that I invested a lot of time into getting the height and tension correct.

Since then, I rarely have skipped stitches or thread breaks, though I’m admittedly afraid to say that out loud, coz you know, those quilting gods like to laugh at us!

I considered getting a more expensive UPS (I think that would be one with sine wave output). We don't think we will be in the house permanently, so I haven't been willing spend that $$ yet. I did talk with someone at one of the companies that sells these (Tripp I think) - to get an idea of what I should purchase. But they said it would be hard to say as we don't know exactly what the problem is.

I hadn't thought of contacting the electric company. I had considered contacting an electrician. Worth asking about for sure!

Since the machine seems to work fine at the shop where I bought it (and it has had routine maintenance there 2x) - I'm thinking the power board in the machine is likely okay.

Our house has aluminum wiring. The connectors have been updated (alumicon connectors). However, we find the house is wired oddly. Upstairs, where my sewing room is, it seems like a lot is on one breaker. Definitely have lights slightly flickering here and there. I think the circuit board in the house should likely be replaced. We've replaced some wiring as we have done some home reno projects.

If I had room in the car on the next trip we take to see our kids (who live in a house newly constructed just a couple of years ago), I would take the machine with me and try it out extensively while there. Might have to see if I can finagle that. Would definitely rule in or out the problem being with the machine (I don't think it is the machine - but you never know!).

Ok my two cents:
Often when you're quilting, skipped stitches are a result of needle flex. The thicker sandwich and added tension due to pushing/pulling the sandwich can cause the needle to bend slightly, and therefore miss the bobbin hook. The fix is to use a larger needle. When sewing on my DSM (Brother 1500), I usually use a 12 or 14 for piecing, but when quilting I got better results and no skipped stitches once I switched to a 16 or 18 needle. By the way - a size 18 is pretty standard for most longarm machines.

I am having the same issue after using the thread cutter. I finally just gave up and clip with snippers now, which is a bummer because that was a huge selling point for me. Did you get any insights?

the machine went back, they had it for a couple of months, apparently couldn’t find anything wrong with it but sent me a NEW machine… that machine started doing it straight out the box… the first machine was fine for about 3 months. The new machine went back, that was looked at, they found the timing was out so ‘fixed it’ and gave me a complimentary service (oh thanks a bunch!?! It’s supposed to be a brand new £2k machine?! It came back and worked for about a week. There is very blatantly a fault with this model machine. I’m not happy and certainly will never buy another Pfaff. My Janome £500 machine I’ve had for 3 years still cuts perfectly. It makes me so mad, sad, angry, guilty for buying the thing. Currently just using snips as I haven’t the mental strength to fight right now.

I know this is an old post-- but what did you ever end up doing? SAME. ISSUE. and I hate this machine! It also doesn't like going over the thicker parts when I use it to make bags.