Longarm Tension Troubleshooting Guide — Top, Bobbin, and Balance

Tension problems are the number one issue longarm quilters troubleshoot. Loops on top? Loops on the back? Thread breaking? This guide covers the most common tension symptoms and what causes each one.

Linda’s Electric Quilters Troubleshooting Guide

Tension Problem Diagnosis

Symptom Likely Cause Solution
Loops on quilt top (bobbin showing) Bobbin tension too tight, or top tension too loose Loosen bobbin tension slightly; check top thread path Fix
Loops on quilt back (top thread showing) Top tension too tight, or bobbin tension too loose Loosen top tension; check bobbin case is fully seated Fix
Thread breaking frequently Top tension too tight, dull needle, or thread snagging Check tension, change needle, re-thread completely Fix
Skipped stitches Dull or wrong-size needle; batting too thick; speed issue Change needle; check needle size for batting type Fix
Puckering on quilt top Top tension too tight; quilt not loaded evenly Loosen top tension; re-check loading and pinning Fix
Bobbin running out fast Bobbin tension too loose — pulling extra thread Tighten bobbin tension incrementally Fix
▶ Golden Rule of Tension Before adjusting tension, always re-thread both top and bobbin completely. More than half of all tension problems are caused by a misthreaded path, not actual tension setting errors. Re-threading takes 60 seconds and fixes most issues without touching any tension dials.

Top vs Bobbin Tension Basics

Top tension adjustments

  • Higher number = tighter top tension
  • Start at center of your machine’s range
  • Adjust in small increments (0.5 at a time)
  • Always test on scrap quilt sandwich first
  • Different thread weights need different settings

Bobbin tension adjustments

  • The tiny screw on the bobbin case controls tension
  • Righty-tighty / lefty-loosey — small turns only (1/8 turn)
  • Keep a dedicated test bobbin case vs “set” case
  • Bottom Line 60wt bobbin thread helps balance tension
  • Never force — if screw strips, replace the case

Frequently Asked Questions

How do I know if my tension is balanced?

Quilt a test piece and examine both sides. Balanced tension means the knot (where top and bobbin thread lock) is centered inside the quilt sandwich and invisible from either side. If you see loops or dots of contrasting thread color on either surface, the tension is unbalanced.

Does changing thread weight require re-adjusting tension?

Yes — almost always. Switching from 40wt to 60wt, or from polyester to cotton, will typically require tension adjustment. This is why running a test piece with new thread is essential before starting a customer quilt.

My tension was perfect yesterday and now it’s off — what happened?

Check the needle first — a bent or dull needle is the most common overnight cause of tension changes. Then re-thread completely. If still off, check that the bobbin case is fully seated. Temperature and humidity changes in the studio can also cause subtle tension shifts.

Shop Longarm Supplies at Linda’s Electric Quilters

Expert longarm advice • Trusted since 1999

Shop Longarm NeedlesShop Bottom LineAll Longarm Supplies