Raising the presser foot opens the tension discs, and only then can the thread drop into the gap between them. With the foot down the discs are clamped shut, so the thread lies across the outside of them and never enters the tension path.
What that looks like when you sew. The top thread meets almost no resistance, so far too much of it feeds into each stitch. The result is loose loops on the underside of the fabric, or a dense nest of thread under the needle plate. Almost everybody meets this fault on a first machine and blames the dial.
Why the dial then seems broken. Turning it up closes discs that the thread is not between. Nothing changes, so people turn it further, and the machine is left badly set once the real fault is found.
The habit worth building. Foot up, thread the whole path from spool to needle, foot down, sew. Every time, including when you are only changing colour.
The same rule applies to a rethread after any fault. When the machine misbehaves, the first move is to lift the foot, pull the top thread out completely and thread it again from the spool. Not to tug at it, and not to guess which guide it slipped out of.
One extra check. Give the thread a gentle pull with the foot up, then with it down. Down should feel noticeably stiffer. If both feel the same, the thread is not seated.
Questions people actually ask
Does this apply to every machine?
To every machine with a mechanical tension assembly, which is nearly all of them. The linkage that lifts the foot is what opens the discs.
I threaded correctly and still get loops.
Then check the take-up lever. Missing it is the other common threading fault, and the symptom is very similar.
Last reviewed 2026-08-11