FAQ
TL;DR: To fix a roller blind that won’t retract, preload the spring 10–15 turns; "The task is child's play." Hold the drum, then hook the belt back on. [Elektroda, balonika3, post #17199751]
Why it matters: This helps renters and DIYers restore belt retraction fast without replacing the whole unit or drilling new holes.
Quick Facts
- Target pre‑load: 10–15 drum turns before hooking the strap; feel tension increasing. [Elektroda, balonika3, post #17199751]
- A freely spinning drum usually means the spring is broken or unhooked inside. [Elektroda, balonika3, post #17201548]
- You can replace only the disc/spring instead of the entire cassette to avoid reinstallation. [Elektroda, balonika3, post #17201548]
- Quick DIY fix: harden the spring tip and drill a new hook hole. [Elektroda, Inkwizycja, post #17203261]
- If retensioning is too fiddly, swapping the whole winder is a sensible choice. [Elektroda, DecoDominik, post #17199594]
How do I fix a roller blind retractor that won't pull the belt back?
Preload the spring, then rehook the belt. Rotate the drum until you feel tension build. Add 10–15 turns for preload. Hold the drum using the side burr, then slip the belt on. Release slowly to confirm retraction. “The task is child's play.” [Elektroda, balonika3, post #17199751]
What’s the step-by-step to retension the winder spring?
- Turn the drum until you feel the spring stretching.
- Add 10–15 full turns to preload.
- Hold the drum (use the side burr) and hook the belt, then release slowly. [Elektroda, balonika3, post #17199751]
Why does my retractor spin freely with no resistance?
That points to a failed or unhooked spring. Inspect the drum’s center. If the hub spins around the plastic spindle, the disc is worn. In either case, tension won’t hold until you repair or replace the spring/disc. [Elektroda, balonika3, post #17201548]
Can I repair a broken spring tip, or do I need a new winder?
You can repair it. Reharden the spring tip and drill a hole sized to catch on the spindle hook. This restores engagement without buying a new cassette. Replace the disc only if the spring steel is beyond repair. [Elektroda, Inkwizycja, post #17203261]
Where can I buy just the pulley/disc or a full retractor locally?
Ask window installation companies and shops that service blinds. They commonly stock belt winders, springs, and discs. Bring your old part for matching. This avoids mismatched sizes and reduces downtime. [Elektroda, olador, post #17203277]
Is adjusting the spring worth it, or should I buy a new retractor?
If you dislike fiddly spring work, replace the unit. Spring adjustment can be tedious and frustrating. A new winder installs quickly and restores smooth retraction. Many DIYers choose replacement over adjustment to save time. [Elektroda, DecoDominik, post #17199594]
How many spring preloads do I need for a typical window roller shutter?
Use 10–15 turns as a practical starting point. Add or remove a turn to fine‑tune pull strength. You should feel clear resistance as you wind. If tension never builds, the spring or hub may be compromised. [Elektroda, balonika3, post #17199751]
The strap fell out of the cassette—what’s the quickest way to rethread it?
Preload the drum first, not after. Hold the preloaded drum with the housing’s side burr. Slide the belt onto the drum and let it retract under control. Test full travel and add a turn if retraction feels weak. [Elektroda, balonika3, post #17199751]
I retensioned several times and it still won’t retract—what next?
Stop and inspect internals. A broken spring or a hub that rotates on the spindle means retensioning won’t help. Replace the spring/disc, or swap the entire retractor for reliability. This is an expected failure mode. [Elektroda, balonika3, post #17201548]
The central hub rotates around the spindle—what does that indicate?
The hub or its interface is stripped. The spring cannot store torque, so the belt won’t retract. Replace the disc or the complete winder. This edge case requires parts, not adjustment. [Elektroda, balonika3, post #17201548]
I don’t have many tools. Can I still do this repair?
Yes. The procedure needs basic hand control. Hold the preloaded drum with the housing’s side burr and hook the belt. It’s simple enough for a calm DIYer. “The task is child's play.” [Elektroda, balonika3, post #17199751]
Any videos or search terms to watch the process first?
Yes. Search YouTube for “zwijacz do rolet” to see belt winder tensioning and threading. Video walkthroughs clarify drum preloading and belt routing. Visuals help you avoid miswinding. [Elektroda, gradek83, post #17199187]
there are some manuals for this or something, for me it is just a spinning circle xD I would like to try to shoot this spring, I have no patience and probably will not succeed, but you can see 
