Have you tried adjusting the return rolls going into the take-up and out of the take-up to track it better through the take-up?

Try doing the same for the tail pulley. If the pulleys are square to the structure and parellel to each other it has to be the return rolls not aligned with the pulleys. ■

Plus or minus 5 mm pulley face width allowance over belt width is not typical. Normally, the clearance should be equal to or larger than +/- 60 mm to allow for belt mistracking, variations in belt and splice construction, structural alignment, windage, et al.

In my opinion, the variations need to be included which require a larger pulley face width.

There are many conditions which can alter the tracking of the belt in the take-up tower. Maybe a sketch would offer insight. ■

The run off on the head side bend pulley can not be generated by the pulley itself unless the diameter has a taper. The cause is most likely the alignment of the head pulley or the snub. At 10 m, it is the ideal distance to reflect belt run off at the take up. It is likely that you are also experiencing wear on the take up bend pulley.

You should find that addressing this one item will resolve the problems that you describe. ■

Have you looked at surveying your conveyor structure? We have a similar problem and we are getting a survey undertaken to ensure that the pulleyas are all in alignment. We have a very wet area around the takeup tower and it appears to have sunk on one side.

Pesty ■

Taper on a pulley face is an inevitable reult of the machining process; even with todays n/c vertical borers. The effect of taper is really luck of the draw. Your drums could be within the reasonable tolerances specified and the taper could produce runout over time.

Shaft alignment and drum face concentricity on the said shafts does not fully ensure that the wrapped surfaces on the drums are true to each other. (Which is what Dave Morgan said)

It will be difficult to measure alignmnet of the drum faces if they are lagged???

Try turning one of the bend pulleys round. That should send the belt only to one side or t'other. Then pack up the bearing block to suit.

(Pesty,

When you get the survey underway will you be asking for a check on saline attack in the foundation rebar?) ■

Hello louispanjang, i wasn't but i will task my reliability Engineers tackle this idea and see what the outcome is.

Thanks ■