OPERATION
PROPER RATE OF FEED
Trimming and edge shaping depend upon careful
The proper feed rate is dependent upon:
•The hardness and moisture content of the workpiece
•The depth of cut. It is necessary that you do not exceed 1/8 in. depth of cut for proper rate of feed.
•The cutting diameter of the bit. Maximum bit size for roundover and edging operations is 3/8 in. max. Maximum straight bit size for rabbeting and dado operations is 1/4 in.
For edge shaping in soft woods such as pine, a faster rate of feed can be used. When edge shaping in hardwoods such as oak, a slower rate of feed will be required. In all wood types, a slower rate of feed is required when cutting shallow grooves.
Several factors will help you select the proper rate of feed.
•Choose a rate that does not slow down the trimmer mo- tor.
•Choose the rate of feed at which the bit advances firmly and surely to produce a continuous spiral of uniform chips or a smooth trim edge on laminate.
•Listen to the sound of the trimmer motor. A
•Check the progress of each cut.
•Notice the chips being produced as you cut. If the trim- mer is fed too slowly, it will scorch or burn the wood. If the trimmer is fed too fast, it will take large chips out of the wood and leave gouge marks.
Always test a cut on scrap piece of the workpiece wood or laminate before you begin. Always grasp and hold the trimmer firmly when trimming.
When using the largest recommended straight bit (1/4 in.) in any type of wood, maintain a maximum cutting depth of 1/8 in. and a very slow feed rate to achieve the best quality cut. A
There is no fixed rule. Proper feed rate is learned through practice and use.
FORCE FEEDING
See Figure 14.
The trimmer is an extremely
Clean smooth trimming and edge shaping can be done only when the bit is revolving at a relatively high speed and is tak- ing very small bites to produce tiny,
Under extreme
TOO SLOW
TOO FAST
Fig. 14
TOO SLOW FEEDING
See Figure 14.
When the trimmer is advanced into the work too slowly it scrapes away
It is more difficult to control a trimmer when the bit is scrap- ing instead of cutting. With practically no load on the motor, the bit will be revolving near top RPM. When feeding too slowly, the bit will have a greater than normal tendency to bounce off the sides of the cut, especially if the wood has a pronounced grain with hard and soft areas. The cut that results may have rippled sides instead of straight.
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