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- If you still do not get a proper charging, take or send tool, battery pack, and charger to a Dremel Service
Station for repair (address are listed on the service diagram supplied with the tool).
Note: Use of chargers or battery packs not sold by Dremel may void warranty
APPLICATION ADVICE
• Always practice on a piece of scrap material first to choose the right accessory and determine the optimum
working speed
• Do not apply to much pressure on the tool; let the speed do the work for you
• Use only accessories that are recommended by the manufacturer for your model.
SPEED
Your Cordless Rotary Tool is equipped with a variable speed control dial. To turn the tool ON, rotate dial to desired
number to select the operating speed needed from 5.000 - 25.000 RPM. To turn tool OFF, rotate dial to the "0" OFF
position. You can refer to the charts on page 4, 5, and 6 to determine the proper speed, based on the material
being worked and the type of cutter or other accessory being used. These charts enable you to select both the
correct accessory and the optimum speed at a glance.
The Settings for Approximate Revolutions Per Minute Cordless Rotary Tool Variable Speed Model 780
Switch Setting Speed Range
0 Off Position
2 1,000 - 5,000 RPM
4 6,000 - 10,000 RPM
6 11,000 - 15,000 RPM
8 16,000 - 20,000 RPM
10 21,000 - 25,000 RPM
Some rules of thumb in regard to speed:
1. Plastic and materials that melt at low temperatures should be cut at low speeds.
2. Polishing, buffing, and cleaning with a wire brush must be done at speeds below 15,000 RPM to prevent
damage to the brush.
3. Wood should be cut at high speed.
4. Iron or steel should be cut at top speed if using tungsten carbide accessory, but at lower speeds if using high
speed steel cutters. If a high speed steel cutter starts to chatter-this normally means it is running to slow.
5. Aluminum, copper alloys, lead alloys, zinc alloys and tin may be cut at various speeds, depending on the type
of cutting being done. Use paraffin or other suitable lubricant on the cutter to prevent the cut material from
adhering to the cutter teeth.
To aid you in determining the optimum operational speed for different materials and different accessories, we have
constructed a series of tables that appear on diagram . By referring to these tables, you can discover the
recommended speeds for each type of accessory. Look these tables over and become familiar with them.
Ultimately, the best way to determine the correct speed for work on any material is to practice for a few minutes on
a piece of scrap, even after referring to the chart. You can quickly learn that a slower or faster speed is more
effective just by observing what happens as you make a pass or two at different speeds. When working with
plastic, for example, start at a slow rate of speed and increase the speed until you observe that the plastic is
melting at the point of contact. Then reduce the speed slightly to get the optimum working speed.
Increasing the pressure on the tool is not the answer when it is not cutting as you think it should. Perhaps you
should be using a different cutter, and perhaps an adjustment in speed would solve the problem. But leaning on the
tool seldom helps.
MAINTENANCE AND REPAIR
• Keep tool, battery pack and charger clean (some household cleaning products and solvents can damage plastic
parts; these products include among others benzine, trichloroethelene, chloride, amonium
• Excessive sparking mostly indicates worn-out carbon brushes, therefor your tool should be brought to a
service station.
• In case of an electrical or mechanical defect, hand in tool at one the DREMEL Service Stations for repair
(addresses are listed on the service diagram supplied with the tool)
The speed of the rotary tool is
controlled by setting this
indicator on the housing.
6
GB