PlaneKrazee

My Feedback: (14)

To make a programmable smoke pump use a $17.00 Sullivan streamer flight box smoke oil pump, a $15.75 GWS ESC100A speed control tower hobbies stock # LXKZZ7 and three .01uf filter caps. You will also need a check valve compatible with smoke oil.

The pump only weighs 3.5 oz and the controller listed has a built-in lipo cutoff so you can safely use a two cell lipo.

Disassemble the pump, remove the motor and solder the capacitors from the motor can to and between the motor leads. Remove the on off reverse switch and install the esc with a little goop. That’s it. After ½ hour and you have an excellent programmable smoke pump.

The pump motor is designed to run on 12 volts so using a 2s lipo pack is no problem. I ran mine on a 5 cell nimh pack and got 18 oz. a minute of unrestricted flow. I experimented with elevated injection pressure, made and installed an injection nozzle with two .014 holes in it to atomize the oil and was able to get 7-9 minutes of scale looking smoke from only 11 oz of oil. The injection nozzle would spray the oil into the muffler and it would really do a good job of breaking up the oil into small droplets. One of the best ways to get good smoke is to preheat the oil. I didn’t do that on this installation but I imagine I could have gotten even more smoke from the same amount of oil. The photo shows the beginning of a vertical tumbling maneuver. Not the best photo, it was ripped from a video I mix the throttle to the esc, smoke starts to come on just above high idle and goes to about 45% at full throttle for best smoke with the least oil.

I was going to try using a brushless motor with a higher quality geared pump but this pump worked so well I didn’t bother. Harris is making a 2.3 oz. brushless smoke pump but is selling it for $150.00.

The premade Sullivan Skywriter pump is a good deal with reasonable markup if you don’t feel comfortable making this yourself. However you should make your own nozzle to increase the volume of smoke.

Back in 2004 I made a programmable on board smoke pump for my GP Chipmunk. I pulled out my notes from when I was researching this stuff. Besides making a cheap pump I was looking into making a setup that would keep the plane clean and save on smoke oil. At $12.00 a gallon it adds up.

The smaller the droplets the better the smoke from the least amount of oil and heat, good for part throttle settings.

The hard part is getting a good atomizing nozzle into a 10-32 fitting so people will use it. One .015 in diameter orifice running 30 psi will pass almost 4 oz a minute. Blasting the oil into the header or muffler at that pressure will give you very fine droplets when it hits the opposite wall. Placing a .014 drill pin directly in front of and just off the face of the orifice will create a fine fog/mist. The alignment of the pin is extremely critical to form the smallest droplets.

I believe 4 oz/min should be enough flow to create scale smoke for even the largest plane although I think the pros use about 8 oz/min. Depends on many factors. My 1/5 scale Chipmunk was using less than 2 oz a minute.



I forgot to add you need to remove the red wire from the wire between the esc and receiver.

Bone

Using a programmable ESC in this manner is an excellent example of lateral thinking. Well done Sky Pilot [8D] You devised the theory & then tested it in real life. We need more thinkers like you.

The same concept could be used for other electrically activated functions on a radio controlled aircraft.

PlaneKrazee

My Feedback: (14)

Bone,

I was not the first to do it. Shortly after I posted how to do this Sullivan and or Slimline came out with a production version with reasonable profit margin.

I checked when I ordered my first esc to use on a smoke pump, it was early 2004.

estradajae

As an almost graduated Electronics engineer, I think even the ESC could be replaced by a much cheaper unit, like a small MCU and a mosfet transistor... even there may be some analog circuits that could be implemented in a small size package to conver the servo signal to pwm to operate the motor... I think ESC ar all the way overpriced.

PlaneKrazee

My Feedback: (14)

You should design it and see how it performs.

estradajae

Yeah, I was thinking about that, but first I would like to know the specs... I mean...how they are usually operated... if you want a separated channel for this or always on...a proportional control, or that the activation..... ??

How muhc would that ESC control you are using?

Jorge

PlaneKrazee

My Feedback: (14)

I set mine up so it is turned on by a seperate channel that is mixed to the throttle channel for proportional control.

pe reivers

Good job Skypilot. The 3W units also are at about USD 150

PlaneKrazee

My Feedback: (14)

I have been asked to do a thread showing how to make one of these. As soon as I can I'll dig out the original test setup, and new pump and parts and assemble one taking photos along the way. I'll post a video of the pump running showing the pressure gauge and smoke oil shooting out of the nozzle. I'm trying to get the smoke oil to break up into a mist.

estradajae

Does the smoke pump really needs a proportional control? or it can be made just using an "on/off" operation?

PlaneKrazee

My Feedback: (14)

I wanted the ablity to control the smoke from my transmitter while flying and slave the output to my throttle. The point for me is to use the least amount oil for the most smoke, reliably. Smoke oil is expensive.

For on/off you only need a pic, 2 amp triac and circuit board.

Justicius

@PlaneKrazee

Can you please write the brushless name and typ.

Thanks!!

PlaneKrazee

My Feedback: (14)

I didn't use a brushless motor. Please read the first post.

Regards,

Brian

Justicius

sorry, I haven't seen it.

I have big problems with sullivan pumps. I've burned 2 motors. And now I'm want to try to repalce brushead motor with brushless. But I don't have an idea which motor to use. I think it shoud be outruner with small KV.

Do you have any suggestion?

Thanks!