Electronically controlled Smoke Pump for onboard smoke systems.

Using the same ultrasonically sealed direct drive pump head as our other electric pumps, this lightweight onboard unit has a miniature microprocessor controlled electronic pulse drive speed control. You can set smoke rate with your transmitter trim, and mix the smoke with the throttle channel if desired. Works with 6V to 12V battery packs. Note: For best results battery of 9.6V or less are recommended unless higher fluid volume is required. The pump weighs only 109 g (3.9 oz) and is 3.8" x 1.4" x 1.4" (96 mm x 36 mm x 35 mm). Includes filter, smoke tubing and antisiphon valve. Estimated smoke fluid burn rate 3 to 6 ounces per minute.

Plug a charged 4.8V to 12V battery pack into the power plug, making sure to observe correct polarity. The higher the battery voltage, the wider the flow control range and the higher the maximum flow rate.
For best results, a 6V to 9.6V battery is recommended unless a higher fluid volume is required. The SkyWriter draws less than 250 mA, so a 150 mAH or greater battery pack is sufficient.

For initial setup, plug the radio connector into a switched channel such as landing gear or flaps. Turn on radio, make sure switch is off (100% negative) for at least 5 seconds and turn on. If the pump pushes fluid toward the muffler, the plumbing is installed correctly. If it tries to pump toward the tank, reverse the yellow tubes on the
smoke pump.

Radio Setup for Non-programmable Radios
Use a switched channel to switch the SkyWriter on and off. Since there is no trim control on a switched channel, there is no flow control, and flow will be at maximum when the switch is on.
Note: Do not run the SkyWriter dry more than 30 seconds as this can cause severe damage to the unit.

Radio Setup for Programmable Radios
The microprocessor on the SkyWriter control board thinks like a servo. When the pump is off, the processor is responding to a full throw in the negative direction. When it is pumping, it responds to a throw past neutral in the other direction, and sets pump motor speed based on the positive throw percentage.

You will have to determine the best settings while the engine is running at normal operating temperature, as the optimum flow rate depends on the engine, muffler, ambient conditions and the specific smoke fluid.

For simple switched operation with single speed flow control, use the ATV settings on the chosen switched channel to set desired flow rate. Note: The off position must be a value below zero, as zero is neutral. We recommend off be negative 100%. Unless the pump sees a suitable value below zero for the off command, it will not initialize properly. Refer to your radio’s instruction manual for specific programming steps if needed.

For mixed control (slaving the SkyWriter to the throttle control) set up as above then follow the radio manufacturer’s instructions for mixing channels. Normally, a low setting would be used at idle and a higher setting used at full throttle.

Maintenance
Old smoke fluid can become “gummy” after a period of time. We recommend back-flushing your SkyWriter smoke system with a moderate solvent periodically. Be sure the solvent is completely removed from your lines before pumping fluid into a hot muffler.

Smoke Fluids
We recommend the use of commercially available smoke fluids. These formulas will not harm your paint or covering film and will produce the thickest clouds of white smoke. Most homebrew smoke formulations will also work although Sullivan will not assume any risks involved in the development or use of these formulas.