RC Tank Warfare community hobby forum

Well, after all the experimenting I have been doing with my smoker it has stopped due to the damn Nichrome wire snapping
I'm gonna try the resistor route now but need some advice on what type.
I have a fair Idea what type of resistor to use, Wirewound and around 18ohms. I've just saw this at a local electronic shop. So I'm just asking for a bit of guidance in the search for the perfect heating element.

http://www.maplin.co.uk/3-watt-wirewound-resistor-2173

-x se7en x-

Hi Se7en,

These are the ones I use in my smokers

http://www.ebay.co.uk/itm/3-WATT-WIREWO ... 4cfafc596e

Not certain if the maplin one you posted would work. As basically using the resistor as a heating element therefore you need it to get hot, the cement block may stop it giving off heat.

I few things to bear in mind about the resistor repair is, the nichrome wire gets hot very quickly the resistor can take a few minutes to get up and running. Not a real problem but don’t expect plumes of smoke straight away. This is all down to the resistor is just that resisting current and not a heater the heat is by product so needs the time to build up.

I’ve used up all my 15ohm resistors so going to order some 12ohm ones and see how I get on with them. I run big capacity batteries so I’m not too fussed about the extra drain on the battery.

Ian.

Thanks tankbear,

Amazingly Those resistors you mentioned are exactly the same ones I bought, But I felt it took way to long to heat up. Anyway I just kindly received a busted hairdryer off my sister. So i stripped it down and got the Nicrome wire spring and used that. I trimmed it down till the current passing through it made it glow

I now have a piece of wire thats about 15cm long. Now I know that this is far to big for the original Heng Long smoker (may their makers be blighted...) So...using this (http://www.scale4x4rc.org/forums/showthread.php?t=25024) tutorial I am making a sightly modified version suitable for a tank (smaller fans, smaller scale project box etc...)

I will post a video or photos or both when I have completed it. I need to get to crappy maplins to get my project box first

-x se7en x-

Yeah agree the warm up time of the resistor is longer than the wire element but once you get use to it is fine.

Great tutorial find . Sure you find parts to make a smaller version. Only comment I suggest is rather than have a big hole for the fan go for a small one, on mine the hole is only tiny 4 or 5mm diameter. This stops the smoke escaping out when fan not running, plus enough air pressure generated by the fan to push through tiny hole. You can play around, always easy to start small and make bigger than other way round. Just remember the hole is better further away from centre of fan as greater pressure.

Ian

I have been doing some experimenting using the 15ohm resistors mentioned and the main thing I found is the addition of the fan improves the smoke output purely by moving more air across the heater element.
In experimenting I opened a unit up and let it smoke to see how much was produced then gently blew across it and the immediate increase in smoke output was brilliant, I'm working on using the fan with the pump so I get a good volume of smoke output with the pulsing effect of the engine tickover which increases on acceleration when you use the proportional smoke units.

Hi Jonger,

The last smoker I did was like what your going to do. Basically started off with standard unit, change to resistor and Kevlar wick, increased the air hole between the pump and tank (for large volume pump effect) added a fan at opposite side to the pump and fed with a smallish hole (4mm I think). I then found the pump was running to fast so added a 5v voltage regulator to slow pump down and also fan, I then added a few diodes off motor supplies which only increased the fan speed.

It all works great. Only thing I say is by the time the smoke is pushed out via pipes and exhaust outlet the effect is diluted a bit, think the exhaust outlets act as a bit of a choke point. So I’m next going to see if I can do anything with it to help.

Ian.