Skipped stitches & looping on the bottom of Quilt

Can I Free Motion Quilt on a Regular Sewing Machine? By National Quilters Circle

Yes

https://www.nationalquilterscircle.com/article/can-i-free-motion-quilt-on-a-regular-sewing-machine/

How to Stitch the Perfect Stitch Length for Quilting
JULY 28, 2020
Today’s Topic: How to Stitch the Perfect Stitch Length for Quilting

https://lorikennedyquilts.com/how-to-stitch-the-perfect-stitch-length-for-quilting/

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

Quilting is a bit more finicky than regular sewing. Be sure to ALWAYS RAISE the presser foot when threading the top thread. FWIW, I use a separate bobbin case for FMQ that I have tightened the tension to keep the bobbin thread from coming to the top of the sandwich, but I tend to use a finer thread for quilting so adjusting the bobbin takes care of it. In your case, however, it sounds like the top thread is staying under the fabric. I would try tightening the top tension. Also, install a brand new needle--a top stitch, embroidery, or microtex needle seem to work well for me. Test well on a sandwich made of the same fabric and batting and get it adjusted well before sewing on your quilt. Sometimes sewing speed will affect stitches under the fabric, or even on top.

5 Free Motion Quilting Problems and How to Fix Them

Correcting Sewing Machine Tension for Free Motion Quilting NQC

LOOPS Tension or Speed

https://www.generations-quilt-patterns.com/machine-quilting-thread.html

https://www.generations-quilt-patterns.com/sewing-machine-tension.html

https://www.generations-quilt-patterns.com/machine-quilting-tension-problems.html

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If the machine has the capability for a stitch regulator, then it is most likely possible. However, stitch regulators need to be attached (electronically plugged in) to the machine. If your machine does not have that, then you are limited to manual stitch regulation. (However, that may not be a bad thing. There are still a lot of professional sewists who continue to perform manual stitch regulation (such as free motion quilting) on mechanical machines. Their work is beautiful, but they have had a lot of practice. Even if they were offered a stitch regulator, most probably wouldn't want it anyway. Harriet Hargrave is probably one of them.
Harriet Hargrave Professional advice and the highest quality supplies for... The last time I saw her working on a quilt, it was a whole cloth silk quilt that she was quilting using a mechanical Bernina.)

You can contact a Janome dealer or search online. It should also be listed as an optional accessory in your paperwork.

https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwj-lejWiKbQAhUH6WMKHYLXBPcQFggjMAA&url=http%3A%2F%2Fjanome.com%2Fsiteassets%2Fsupport%2Fmanuals%2Fretired%2Fcomputer%2Finst-book-mc4800.pdf&usg=AFQjCNGCPQc_wJyl_Ts_4bFZ-7M3hX1ZnA&cad=rja

....

a quilting foot or buy one with a round hole in it great

Hmm, have you installed a brand new needle? Make sure the needle is compatible with the thread and fabric. Sometimes a top stitch or microtex needle will work better for free motion quilting or darning.

https://www.superiorthreads.com/education/what-causes-skipped-stitches

https://moonlightingquilts.wordpress.com/2012/04/19/skipping-the-skipped-stitches-in-your-free-motion-quilting/

https://www.generations-quilt-patterns.com/skipped-stitches-driving-you-nuts1.html

Using a long carpenter's level, level up your frame. Low areas in the frame can cause skipped stitches. Also, check the wheel sensor wheels-are they making good connection? These can lose connection when you quilt in certain directions.

Use a carpenter's level to level up your frame, and be sure to keep the quilt leveled up to barely above the throat plate on the machine, and level front to back. Check the connections on the regulator sensors. If even one is not making good connection, you'll have skipped or broken stitches.

It sounds like one of your clearances in the machine is off. When a machine skips stitches like yours is doing, it does so because the hook responsible for "catching" the thread from the needle is not close enough to the needle so it misses the loop of thread from the needle. If your machine was having a timing problem it wouldn't sew well on any fabric. A clearance problem shows up on certain fabrics at certain times. A few things you could do to try to compensate it would be to use a slightly larger needle and turn your top tension dial down to a lower setting. Move the machine a little slower on the frame or increase the speed of the machine. Either way a trip to your technician will be needed. Make sure you tell him to check the needle to hook clearance.

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.