Gear 20 Teeth With Bushing Module M1: Fitting and Troubleshooting
By eitech Metallbaukasten | Published: 2026-11-05
Category: Consejos y cuidado
Diagnose common fit and running problems with the eitech Gear 20 Teeth with Bushing Module M1, from slipping and misalignment to wear, and know when to replace it.
Quick answer
Most problems with the eitech Gear 20 Teeth with Bushing Module M1 come down to three checks: the bushing must sit flush and turn freely on its shaft, the gear must mesh at the correct center distance with another module M1 gear, and the teeth must be free of burrs or wear. Work through the diagnosis below before replacing the part.
Why module M1 matching matters more than tooth count alone
Module M1 describes the tooth size, not the number of teeth. A 20-tooth module M1 gear will only mesh smoothly with another module M1 gear; mixing modules creates tight spots or excessive play that no amount of adjustment can fix. If you are unsure what you have, compare the tooth profile with a known module M1 part before forcing anything.
The 20-tooth size sits in the middle of the eitech range, so it is often used as an idler or intermediate gear. That makes alignment especially important: a small tilt at the bushing translates into uneven tooth contact along the face width.
When the bushing fit is the real culprit
A bushing that is too tight will bind the gear on the shaft; one that is too loose will let the gear wobble and slip under load. The eitech bushing is designed to be a sliding fit, so you should be able to spin the gear by hand with minimal side-to-side rock. If the gear rocks visibly on the shaft, inspect the bushing bore and the shaft for burrs or dirt before assuming the gear is worn.
Do not ream or file the bushing as a first step. Clean it, check that it is seated squarely, and test again. Permanent removal of material is a last resort and will not be reversible.
Symptom-to-solution diagnosis
- Gear slips or jumps teeth under load: Check that the mating gear is also module M1 and that the center distance is correct. Remove the gear, inspect the teeth for flattened tips or debris in the roots, and clean the teeth with a soft brush. Reassemble and test with light load before running at full speed. If slipping continues after cleaning and correct meshing, measure the bushing bore for wear.
- Gear wobbles on the shaft: Inspect the bushing for a loose fit: the gear should rotate without noticeable side-to-side play. If the bushing is worn oval or the shaft is scored, replace the bushing or the gear. Do not shim a loose bushing with tape or paper. A wobbling gear will wear its teeth unevenly, so fix the fit before running the model.
- Teeth show wear or damage: Light burrs can be dressed with a fine file, but remove as little material as possible. Deep gouges, cracks, or missing teeth mean the gear should be replaced. Use the item code 01475 to order the correct eitech Gear 20 teeth with bushing module M1. After replacing a worn gear, check the mating gear for matching wear; a worn pair will quickly damage the new part.
- Gear binds or is hard to turn: Loosen the shaft mounts slightly and re-align the gear train by hand before tightening. Check that the bushing is not pressed against a frame or collar. If binding persists, remove the gear and test the bushing on the shaft alone to isolate whether the gear or the shaft is at fault. Binding that remains after alignment points to a bent shaft or a distorted bushing, not the gear teeth.
- When to stop adjusting and replace the gear: Stop troubleshooting and replace the gear if the bushing bore is visibly oval, if more than two adjacent teeth are damaged, or if the gear has cracked at the hub. Repeated adjustment of a worn part will not restore reliable running. Keep a spare gear on hand for models that run frequently; replacement is faster than repeated repair.
Product facts
- Gear 20 teeth with bushing module M1: eitech Gear 20 teeth with bushing module M1, item code 01475, is part of the eitech Manufaktur range and is supplied in a Standard variant. Knowing the item code and range helps you order the correct replacement if diagnosis shows the gear itself is worn or damaged.
Gear 20 teeth with bushing module M1
