I have a Pfaff 4.2 Quilt Expression. I am free motion quilting and the bobbin thread keeps hanging up. Any suggestions?

Question edited for clarity.
Question moved from Laundry Dryers.

The manual shows various parts

https://www.manualslib.com/manual/594658/Pfaff-Expression-Line.html#manual

There are no exploded parts schematics

https://www.google.com/search?q=pfaff+quilt+expression+4.0+parts+manual

and no Service Manuals available to the public

https://www.google.com/search?q=pfaff+quilt+expression+4.0+service+manual

....

The PC8500 does not do free motion well because of its tension design, it is not you.It was one of he earlier machines to set tension by the thickness of the fabric. If you really want to do free motion then it is time for a different machine.

Tension for stitching a quilt sandwich is tricky. It helps if you use the same color for top and bobbin thread,. If your quilting thread is not the same weight (either heavier or lighter) than thread used for regular sewing, then the bobbin tension may need to be adjusted. My quilting thread is lighter weight so I have a separate bobbin case whos tension has been adjusted specifically for quilting. The goal is have both threads meet in the middle of the sandwich. If the top thread is showing under the sandwich, you probably need to tighten the top tension so it will pull the bobbin thread up into the sandwich. Do the reverse if the bobbin thread shows on top.

It may also make a difference by changing the type and size needle. I tend to prefer a top-stitch needle. An embroidery or microtex may also work for you.

Machine Quilting Thread and Tension

Tension troubles on your quilting machine Try these tricks

5 Free Motion Quilting Problems and How to Fix Them

Thread tension in this machine is set electronically to vary by type of stitch. There is also an alert light pertaining to the bobbin.

Getting The Quilt Expression 4 2 Ready For The Test Drive

Sewing

The first link also offers a further link to an online guide. That said, as the tension is electronically controlled and if any sort of fine tuning is required, that would likely require a trip to a service center. Hopefully, one of the videos provided by the links above will be helpful

Although the dealer may no longer sell the "original" foot for your machine, there are usually "used" presser feet available from sites like eBay. OR, you can purchase non-Pfaff presser feet that will work just as well on your machine. Just be sure to verify that the presser foot is compatible with your model (the shank style will determine whether it will work on your machine).

Pfaff Free Motion Open Toe Quilting Foot

Free Motion Darning Foot Pfaff 820243096

Pfaff Presser Feet

The top thread breaks

1. the needle thread is not threaded properly

2. The needle thread tension is to tight

3. The needle is bent or blunt

4. The needle is incorrectly inserted

5. The needle thread & the bobbin thread are not set under the presser foot when starting to sew

6. the threads were not drawn to the rear after sewing

7. The thread is either to heavy or to fine for the needle

8. Try a different spool or cone of thread

try contacting Pfaff customer service for a manual

Turn your machine off, then turn it on again to re-set everything back to "normal". Now, go into the SET menu (second page, I think) and turn on Q-Sensor Foot and Free Motion. Go back to the Menu and choose the V Menu, Stitch 1. Lower your feed dogs (personally, I don't do this but all instructions always say to do it). Make sure your upper thread and your bobbin thread are a similar thickness i.e. don't use a 35wt top thread and regular sewing thread in the bobbin - it will be too hard to get a balanced stitch with this combination. Use a new sharp needle that has an eye big enough for your chosen thread. When you load the bobbin, be sure to feel and hear the thread "click" into the tension slot. Use one of the free motion feet - my favourite is the spring loaded metal horseshoe shaped one, but there are several and they will all work. (If you are not using the spring loaded nor the Q foot, go back and turn Q Sensor Foot off in the Set menu.) Make sure ALL the weight of your quilt is supported on your table - any tiny bit hanging over the edge will create drag and make it much harder for you to free motion quilt. Most free motion instructions say to lay your hands on the quilt and glide it around. That has never worked for me. I grab the quilt either side of the bit under the needle and steer it that way. So long as the quilt is well basted, it won't cause puckering. Now, the hardest bit - relax! Remember you are only ever quilting a pot holder - the 6" or so square bit that is actually under the needle. Do that little pot holder and move the quilt and your hands on to the next bit. Sure you may come back to an unfinished bit in order to complete your design, but you are only ever focussing on that small area at the needle. Try to watch where you are going, not where you are presently sewing. Believe me, it works!
If you are still having tension issues, you may need to adjust either the top or the bobbin tension. Do this in small increments only and make a note of where you started from. I try not to alter my bobbin because it has been set by my technician at the best place for regular sewing and embroidery, therefore I have a spare bobbin case that I can fiddle with to my heart's content. If you are going to do a lot of FM quilting this is a very worthwhile investment. Most recently I quilted with King Tut 40wt in the top, Signature 40wt in the bobbin. I had my machine set as above, the bobbin tension was a LITTLE lighter than "normal" and it sewed perfectly. You also need the needle down turned on. Good luck!

this is a known issue with the pfaff.....i have just bought the machine and it has thread uptake issues...thread tension issues and it comes unthreaded by itself often...leaving globs of thread on the bottom stuck in the feed dogs and under the throat plate.....then the stitches are not properly balanced because the tension gets too loose on the bobbin thread....very disappointed to find out it is a known issue with all the viking husqvarna made machines...which are pfaff, janome and viking.....sux.

Might be that you need to lower the tensions quite a bit, you'll have to juggle with top and bottom tensions though, and experiment for just this operation with the Sensormatic.