Tim,

I haven't deliberately tested to destruction, but I have abused the heating coil during development. On the whole, I have tried to keep the coil operating conditions as close to the normal use as an e-cig, i.e. wick wet with smoke fluid and an air flow over the wick/coil. To reduce the risk of the wick running dry, I expanded the smoker fluid storage by adding a reservoir tank to the original e-cig reservoir. The new tank is made from acrylic tube I had in my 'useful bits' box. It is important that the reservoir is airtight, otherwise the wick floods. The filler hole is closed off with a caphead screw and o-ring. JBkiwi has recently demonstrated a refillable reservoir with a pump to keep it topped up.

I'm sure that without fluid, the coil will heat up more, and would, if it gets hot enough burn out. That will depend on how much current is being passed through it. I have let some of mine run dry without failure. The e-cig housing does get warm, but not too hot to handle. I assume this is also the case when used for it's original intended purpose. So not so hot that it would cause a fire, unless the current is set too high, in which case the coil would likely burn out quickly removing any risk of fire.

There are different coils available, with different electrical characteristics. The ones I am using draw a current of around 1A on 3V. I make sure that any electronic drivers I am using have a current rating way in excess of that, so haven't had any failures due to the coil running dry or burning out.

For the gunfire simulation I do run the coil continuously with no air flow for much of the time. That way there is plenty of smoke to blow out of the e-cig when the air pump is switched on. I haven't had any coil failures with this. The only coil I have destroyed occurred when I accidentally applied a fully charged 2S LiPo direct to a coil. It vapourised within milliseconds!

Graham93

Gunfire

▶️

Jonathan,

Have you tried glycerine as a smoker fuel? Just dilute it a bit with water to reduce the viscosity.

Graham93

Here is my version. The same arrangement as JB has shown but controlled from a switched channel on the transmitter. The first flick of the switch starts the air pump and fills the balloon. A reed switch on the balloon container switches the pump off when the balloon is full. Subsequent flicks of the Tx switch release air from the balloon through the e-cig for a fixed duration puff and restart the pump to top up the balloon.
Graham93

Gunfire

▶️

Doug,

Jbkiwi and I are already well down the development path for a solution to produce a puff of smoke. More to follow soon......
Graham93

Martin,

I agree it should appear to be less, but I do want some to be visible for the effect. If no one can see it, there isn’t any point in having it installed. Been discussing this with jbkiwi and we are looking at creating a ‘cloud’ of smoke on engine start, then reducing to a lower level on
tickover.
Graham93

Thanks Martin, probably a bit to much smoke in the video, looks like it is on fire 🔥. The smoke isn’t so thick when she is moving. I need to adjust the smoke controller to reduce the smoke when stationary, and increase it when moving.
Graham93

Peter,

I used Halfords rattle cans for the hull. Black and Red primer, over coated with their clear lacquer. The deck was textured using Halfords texture rattle can and then finished with Humbrol enamel No 5 Dark Admiralty Grey. Having read that the superstructure sides should be lighter, I mixed some white into the Dark Admiralty Grey for that. Probably not enough as they don’t look much lighter. I don’t know how close it is to the original, but I’m happy with the final result.

Regards Graham93

Hi Peter,

I haven’t found it necessary to seal the hatches. I get very little water coming over the sides and into the cockpit, etc. Just a few splashes.

Regards Graham93

Hi Peter,

Yes, it was great to get it on the water for it’s maiden voyage yesterday. The simple, all white paint job is intended to contrast with a dayglo orange ripstop nylon sail - that I still have to make!
Regards Graham93

Michael,

I do, but unfortunately in 1/16th scale 👎

Michael,

I have no first hand experience with these particular switches but, looking at the wiring diagrams, they do connect differently.

The second switch you have takes the power for the load from the receiver. The red and black output leads simply connect to the two terminals on the pump. If you use this one, you will need to be sure that, if you are using a BEC to power the receiver, it must have enough power rating to power the pump as well as the receiver, servos etc.

I would choose the Turnigy if I had these two options to choose from

Regards Graham93

Hi Ed,

Looks like you have a real challenge to keep you busy for quite a while. Lots of useful information about Crash Tenders on this site.

I’ve used a 1250kv brushless with a 3S LiPo and a 35mm prop on my 34” Crash Tender and it gets on to the plane easily. I have to be careful on the local pond not to create too much wake and upset the other boaters. I found it didn’t work so well with a larger prop.

Looking forward to seeing more of your rebuild.

Graham93

That looks great, must have taken ages to paint all those figures, and not a mobile phone in sight!

Hi Peter,

With a regular motor, the higher the voltage, the more current it will draw - and the more water it will pump. Best to measure the current with an ammeter in one of the motor leads. Then you can check that your switch can handle it, and fit a fuse to protect things if something goes wrong.

Regards Graham

Hi Michael,

I expect it will be fine, provided the pump draws less than the 10A switch rating.

I have used a home built RC switch with a similar spec for the pump on my Crash Tender. My pump is spec’d at 12v and is running from the 3S LiPo propulsion battery. It only draws about 1-2A normally. Everything worked fine until the pump seized (I think it had muck jammed in the pump gears, despite having a water filter in the plumbing) Fortunately I had 3A fuse in the pump circuit and it simply blew that. The RC switch survived intact.

In discussion with jbkiwi, we felt it would be a good idea to bring together into one post the different smoker experiments we have each conducted to make them easier to find for anyone interested in having a go. Here is a summary of my experiments. JB will add his in time.

My implementation is based on an e-cig H2 atomizer. These are readily available at low cost. The unit as purchased comprises a 2ml tank, heating coil, and a coupling which would normally connect to the e-cig electronics/battery. I made a simple end cap from acrylic which is a push fit into the coupling. Any insulating material could be used for this, even a piece of hardwood could be carved to shape. The end cap is held in place with a couple of small screws through the side of the coupling. Before fitting, it was smeared with silicone sealant to ensure an airtight seal. A central screw in the endcap can be adjusted to make electrical contact with the coil. The other contact to the coil is via the body of the coupling, using one of the endcap retaining screws. A brass tube fitted through the side of the endcap allows air to be pushed through the atomizer.

For installation in my Crash Tender, I increased the capacity of the smoke fluid tank by adding an additional tank around the outside of the original atomizer tank. The smoker fluid I use is 3:1 glycerine:water.

The coil seems to work best when energised with around 5 watts of power. This can be achieved by using a DC-DC converer to drop the battery voltage to around 3volts. Simple low cost buck converters are available on-line. As an alternative, a PWM electronic circuit can be used to power the coil direct from the battery voltage, provided the power to the coil does not greatly exceed 5w. I found to my cost that feeding 25w of power into the coil (circuit error!) vaporises the coil in the blink of an eye! Fortunately, replacement coils are readily available. The exposed metalwork of the atomizer typically reaches a temperature of 30 -35C while it is running but that depends on how much power you feed into it.😉

The air pump is not critical. I have tried a couple of different types and the both work well. It is useful to be able to adjust the pump speed, and hence the volume of air being pushed through the atomizer. Small motor speed controllers are easily obtainable.

The atomizer works best mounted in a horizontal position. if mounted vertically, as shown in part of the video, it has a tendancy to flood the coil.

By adjusting the pump speed and the coil power a range of different effects are possible. The video shows several examples of different settings. It is possible to generate just a gentle waft of smoke suitable for a funnel on a tug or a quick pulse of thick smoke possibly suitable to simulate gunfire on a destroyer.

For my Crash Tender I mix pulsed smoke with water using a venturi type connector and then feed the resulting mix out through the exhaust ports. More details of the installation in the Crash Tender can be found in my Crash Tender Refit blog.

Happy to try an answer any questions.

Graham93

https://www.ebay.co.uk/itm/GS-H2-Bottom-Coil-Clearomizer-Atomizer-eGo-Thread-8-Colours-1-3-5-or-10/201893608808?hash=item2f01cbfd68:m:mAAMZyfFPZqsMzB9Nqg6d5Q

🔗

Smokers

▶️

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Michael,

Those look really smart. Looking forward to seeing them in action.

Graham93

Pete,

Re: wish I had your ingenuity for solving a problem.

Thanks, it is the problem solving that makes it interesting for me. That and the electronics. Helps keep the mind busy.

When I first built the boat many years ago it was as a platform for the home made 27MHz radio, which was not very reliable. Neither was the diesel motor. Nowadays the radio and the propulsion are no problem, so it gave me the chance to work on some more interesting bits.

Regards Graham93

Robbob,

Re: I'd say that she is really now 'fully loaded'.

Yes, not much room left inside for anything more, all 10 channels on the Rx in use, and if I add any more weight she’ll become a semi- submersible 🤣.

Thanks for the comments, and all the guidance I got from your blog.

Graham93

The last gadget to be added to complete the Crash Tender refit is the searchlight.

The body is made from a short piece of 15mm copper water pipe. A domed piece of copper soldered to one end closes off the body. The tube is just the right size to take a 1W LED and lens. The front cap was made from a ring of copper cut from a Yorkshire fitting which slides over the body of the light. Two small nuts (8BA) soldered 180 degrees apart on the circumference of the body provide mounting and pivot points. The body is mounted to a U shaped brass bracket which in turn is soldered to a brass tube.

In addition to being able to rotate the searchlight, I wanted the challenge of making it elevate. A mechanism mounted under the wheelhouse roof provides both the rotation and elevation mechanics. A small servo provides the rotation function. Two plastic gears, salvaged from a defunct inkjet printer, couple the servo to the brass searchlight mounting tube. The gear ratio gives the searchlight a rotation of 270 degrees.

To provide the elevation function, a pushrod passes through the centre of the searchlight mounting tube. As this pushrod is moved up and down, it adjusts the elevation of the light via a wire connected to an arm on one of the searchlight pivots. The pushrod is hollow and tapped with an M2 thread. A length of M2 studding threaded into the end of the pushrod is rotated by a small stepper motor. As the motor rotates the studding pushes or pulls on the pushrod, thus elevating the light. A small scratch built electronic module converts the demand from a receiver channel into step commends for the stepper motor. The motor was salvaged from an old floppy disk drive.

The completed assembly was primed and then painted with Tamiya Gunmetal Grey. The LED is driven from an RC switch and constant current source and is quite bright, even in full sunlight.

Graham93

Searchlight

▶️

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Thanks Phil, it’s reassuring to know it will sail itself. Does that mean I can’t go wrong? I doubt it......

When are you next planning to be at the Pavilion Gardens? It would be great to get the chance to see one of your Wee Nips. I’m not far away.

Graham93

Martin,

I guess I must have been good 🤣. Not sure my wife would agree 🙄.

I’m going to trace round all the parts before I start assembly, so that was a good suggestion. Whilst I have the plans in the kit I got, it will be much easier to trace from the parts than from the plan.
Graham93

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Hi All,

Thanks for the positive comments. I’m happy with the result so far, but it isn’t quite finished. One more gadget still to add. Then I need to sort out the weight distribution. It’s a bit stern heavy, and has slight list to port. I’m hoping that moving one of the LiPos will fix that.

JB, I did try to get some video on the lake this week, but the result wasn’t worth posting. Handheld is impossible while also trying to control the boat. It moves too quick and needs constant attention to avoid running into the bank, or other boats. Need someone to help, either with the boat, or the camera.

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Santa came early today! ⛄🎁

Having almost completed the refurb on my Crash Tender, and inspired by this thread I asked Santa if he could deliver early this year.

This is only my second boat, and my first ever sail boat. I know little about sail boats, how to rig them, or how to sail them so I'm looking for plenty of advice from those with much more experience than I have.

Graham93

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Hi -.-

That’s really useful info. I didn’t realise that the vape coils were driven with PWM. Thought they were just driven direct off a single LiPo cell. I’ve been driving the coils I’m using at a constant voltage of around 3v from a buck converter from the 2s LiPo I have in the boat. It works fine like that, plenty of smoke and it doesn’t overheat, but maybe I’ll try driving it with PWM direct from the LiPo. That will have a few advantages in terms of making the power easily adjustable, and doing away with the buck converter.

Graham93

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Hi Michael et al,

This website is strange sometimes. Despite following your blog Michael I didn’t get notifications for any of these recent pump posts so I missed them. Found them by chance today.

As you may have seen in my latest blog post, I’ve used the black screen wash pump, on a 3S LiPo and it gives acceptable results. I think the pipework, especially through the body of the monitors, produces quite a resistance to the water flow. Bear in mind that my monitors are 1/16th scale so the passageway bores are that much smaller.

Graham93

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Doug,

Hadn’t noticed that! But not so exciting I’m afraid, just an autumn leaf 😂🤣

Based on the build described in my previous 'Fire Monitors part 4' blog, the performance of the fire monitors on the lake was less than impressive so I decided to rework the plumbing.

The solenoid valve based solution worked, but the water flow was restricted by the small bore of the valves. Using two valves to divert water from the ESC cooling to the monitors also meant that one or other of the valves was always energised resulting in unnecessary battery drain. To overcome these limitations, a diverter valve was constructed based on a 10mm compression fitting from the local plumbing store. A central rotor was turned on the lathe and then cross drilled to produce a three port valve which is actuated using a small servo. I wasn't sure that this would work without leaking, but with an o-ring fitted on the rotor shaft it seems to be OK. At one extreme of the servo rotation, water is routed from the pickup scoop to cool the ESC and motor. At the other extreme of travel, water is routed from the pickup to the monitor pump. An RC switch connected to the same Rx channel as the valve servo switches the monitor pump on when the valve is routing water to the pump.

The pump was also upgraded. I have tried a variety of pumps sourced on-line, most of which did not have adequate performance. The pump now in use is an aftermarket windscreen washer pump which seems to work OK.

To make it easier to install in the model, a ply chassis was constructed to hold the valve, pump and the RC switch. The chassis also provides a locating box for the LiPo.

Out on the lake this afternoon, I was able to get a few photos of the monitors in operation. The performance is much improved.

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Michael,

Nice to see a clear set up on the bench. Must make it much easier to work on than it will be once it is in the boat.

I have also found that getting the monitors to work adequately is not as simple as I first thought. I’m still trying to find a solution. At present the flow from my monitors is quite underwhelming 😔. Have you found that the black pump in the bottom centre of your photo gives a good flow? I have just acquired the same model, but it has been too cold to go down to the workshop/shed to try it out.
Graham93

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That’s effective. Please tell us more about the setup you used for that.

Graham93