Blade guide rollers ensure that the bandsaw blade cuts straight. Flat spots on the rollers start when the blade's deflection is wrong, whereas the correct deflection pushes the rollers down on the blade. The proper deflection will ensure that the rollers turn at the same speed as the blade.
When the deflection is incorrect, the rollers will stop turning, and the spinning blade will cause flat spots on the rollers; this will also cause the blade to heat up and snap.
Be sure to clean and oil the rollers daily to stop rust.
How to set the deflection:
1) Loosen the rollers to ensure they don't press on the blade.
2) Set the blade tension to the correct level.
3) Measure the distance from the sawmill bed to the blade – e.g. it will be 250mm.
4) Set the rollers so that they press the blade 6mm downwards.
The distance from the bed to the blade should now be 244mm.
5) Tighten the locknuts.
