Establishing Drum Height; Selecting Sandsmart™ Feed Rates - Jet JWDS-1632-M Gebrauchsanleitung

It may take experimentation to determine proper
depth of cut, given the variables of abrasive grit, type
of wood, and feed rate. For best results, use scrap
wood to practice sanding and to develop skill and
familiarity with the machine before doing finish work.
A combination of several variables will determine
proper depth of cut to use, including the following:
1. Abrasive type and grit size.
2. Width of piece being processed.
3. Hardness of piece.
4. Feed rate of conveyor belt.
NOTE: The use of a carrier or backer board (not
provided), is recommended for cuts 1/16" or less. This
is a flat board, usually of wood or MDF, slightly larger
than the workpiece and of even thickness, placed
beneath the workpiece as it is fed through the sander.
The workpiece may be attached to the carrier with
rubber cement, carpenter's tape or some other easily
removable adhesive. However, some operators use a
rubber or textured surface on the carrier to help
stabilize the workpiece by simple friction.

9.4 Establishing drum height

A good rule of thumb when sanding with grits finer
than 80:
1. To establish drum height, position stock under the
drum. Do NOT start drum.
2. Lower drum to the stock thickness, making sure
drum can still be rotated by hand while just
contacting stock.
Do not start drum while in
contact with stock.
3. Without changing drum height, turn on conveyor
and run the stock out from under the drum. Start
sanding drum and sand stock at that same
position.
4. With the drum operating, feed stock under the
drum from the infeed side and against the
rotation of the drum. Always maintain control of
the stock to avoid kickback and/or slippage.
NOTE: If motor heats up during operation, depth
of cut may be too great for size of grit and/or feed
rate may be too fast.
For sanding with grits coarser than 80, you can lower
the drum slightly.
Always maintain control of stock. Through practice you
will learn the proper depth of cut considering the
variables above.
9.5 Selecting SandSmart™ feed rates
A faster feed rate allows faster sanding but fewer
revolutions of the drum per inch of sanding. A slower
feed rate provides more revolutions of the drum per
inch of sanding to allow a greater depth of cut and
smooth sanding.
Begin experimenting with the feed rate set at about
40% to 50% of maximum. The best feed rate will
depend on a number of factors, including type of stock,
grit and depth of cut used, and whether the stock is fed
directly in line with the conveyor table or at an angle.
If the drum motor is lugging down, if conveyor belt is
slipping, or if you observe a ripple effect on the stock,
slow the feed rate. If the finish is smooth and the
machine is not overworking, you can experiment using
a faster feed rate.
The SandSmart controller continuously monitors the
load on the drum motor, and automatically regulates
the speed of the conveyor motor to maintain the
highest feed rate without overload.
When the red indicator light (B, Figure 9-2) comes on,
the SandSmart control has detected too great a depth
of cut and/or too fast a feed rate.
If the load on the drum motor increases, the
SandSmart control will decrease the conveyor feed
rate and will stop the conveyor under extreme
conditions. If the load on the drum decreases,
SandSmart will increase the feed rate but will not
increase it faster than the manual setting on the speed
adjustment label.
The best and most consistent finish will be achieved if
the conveyor does not change speed during operation.
This change in conveyor speed may affect the finish
surface. If the finish is affected, make another sanding
pass without changing any settings. If the finish is still
affected, make adjustments by slowing the conveyor
and/or decreasing the depth of cut and run the stock
through again.
Also try a faster feed rate or less depth of cut if the
stock you are working begins to show burn marks.
With cherry, hard maple or other hardwoods, using a
shallower depth of cut and a faster feed rate will help
minimize burn marks. Slightly angling the stock as it is
fed into the machine will also help prevent burning the
stock.
Because of the wide range of variables, it is important
to experiment with your specific conditions and make
adjustments to achieve the optimum feed rate. If
14
Figure 9-2