Coverstitch Machine Tension Problems - How to Fix Them
If your coverstitch isn't looking right - loops on the top, loops on the underside, uneven stitching or puckering - it's almost always a threading or tension issue. Here's how to identify what you're seeing and fix it.
Before adjusting anything - check these first
Tension adjustment should always be the last thing you try, not the first. Incorrect threading causes more tension problems than anything else and no amount of dial adjustment will fix a threading issue.
- Re-thread the machine completely with the presser foot raised before adjusting anything
- Check the thread is flowing freely from all spools with no catching or snagging
- Check the needle - a blunt or wrong needle can cause uneven stitching that looks like a tension problem
- Make sure all threads are the same weight - mismatched thread weights cause tension imbalance
Understanding your tension dials
Most coverstitch machines have separate tension dials for each needle and the looper. Each one controls how tightly that thread feeds through the machine as you sew.
- Increasing the number tightens that thread's tension - decreasing it loosens it
- Always make small adjustments one dial at a time and test on scrap fabric after each change
- If you're not sure where to start, reset all dials to the default setting and work from there - default settings are usually marked on the machine or in the manual
What a balanced coverstitch looks like
The top of the fabric should show two or three even parallel lines of stitching with no loops or puckering. The underside should show a neat, even chain linking the needle threads together.
A balanced triple coverstitch - even parallel lines on top with a neat chain on the underside and no loops or puckering on either side.
Identifying and fixing tension problems
Use the table below to match what you're seeing to the correct adjustment. Remember - make one small change at a time and test on scrap before making further adjustments.
| What you see | What to do |
|---|---|
| Loops on top of fabric between needle lines | Needle tension too loose - increase needle tension |
| Loops visible on underside of fabric | Needle tension too tight - reduce needle tension |
| Looper thread visible on top of fabric | Looper tension too loose - increase looper tension |
| Fabric puckering or tunnelling | Needle tension too tight - reduce needle tension. See our Fabric Tunnelling guide for more help |
| Uneven or inconsistent stitch | Re-thread completely and check all spools are feeding freely |
Still having trouble? We're here to help.
If you've worked through the guide and your tension still isn't right, get in touch and our team will take it from there.
Still stuck? We are happy to help.
Our service team has seen every machine in our range and can usually diagnose problems over the phone.
