table, with the concave side down. A few cuts are made out of the red section "A".The timber is turned end for end and the same procedure is done to the section "B". This is repeated as required with the operator sighting along the length of the timber from time to time to check on straightness of the timber. When the timber is almost straight, the guard is replaced and the last cut is made in the normal way.

Twisted material is treated in a similar way. The operator lays the timber on the bed of the machine and rocks it slowly from side