Replacement for nichrome coil...

[jacko]

I only have 510s, so I have no idea what any of the other eCigs look like...., and the mod that I am working on would use custom sizes (to be made from easily available parts, like Home Depot tubing) - my only humble request is that it be kept under 10mm in width!

You bring up a good point. I wonder if a custom e-cig is in order here?

 

[Bubo]

You bring up a good point. I wonder if a custom e-cig is in order here?

Baby steps... One by one!

My idea is simply to keep everything streamlined and the same size - I don't have the experience yet - but basically a 14500 in a tube, that screws to the "New Fangled" atomizer to a readily available cart... I just want something that I can put in my shirt pocket, but has a battery that lasts longer!

A 8.5-10mm wide atty could be used in 510s and others.. I guess that there would be a sweet spot for the width that would fit most existing eCigs, but as I said earlier I only have 510s, so someone with lots of types/brands would be better to pick it...

 

[roadkilldeluxe]

temperature stuff

Sounds good. Not sure of any threads on that subject though, there are not many people here with the equipment to make those measurements. I really like this thread though. Keep in mind he used 6V.

safety stuff

That all sounds pretty good. I am not too concerned about the leads themselves because they usually do not get too warm (at least the exposed part). That is, unless they contain a lot of Lead, which I would try to avoid no matter what temp it reaches

size, design, airflow

I agree with you 100% about the airflow problem and solution.

Wicking--the goal should be to keep the heated area as small as possible, and the amount of liquid touching it should also be kept to a minimum. I highly doubt having too much liquid will cause an ejuice "explosion" (although that would be awesome ); rather, we will get no vapor at all.
-Heating area too big: too much energy wasted
-Too much liquid in contact with heat surface: keeps heater cooler and so it takes much longer to heat up, ends up wasting energy because you are heating a pool of liquid rather than the 1/2 drop you actually need.

This is where current attys work well: The coil (heated area) is very tight and small. The actual amount of liquid touching it is small. If you think of the atomizer as a hot plate, what we (ideally) would want is to let 1 drop touch it and boil instantly. We could let a cup of water sit on it and wait to boil, but we really only need a tiny bit at a time.

durability

awesome.

Just to make sure I understand correctly--the smallest possible size is 10mm long by 3.8mm in diameter?

my guy got back to me

All of that sounds pretty good. However, it would be nice to see some design ideas. It would help find potential problems and keep ideas flowing. I'm finishing up some diagrams right now.

 

[jacko]

Okay, this is how I see things so far.
Temperature stuff: Sun Rod is designed for specific temperatures..... this in enclosed so I am not sure why the temperature would be important at this point. It seems that it would be pre-designed for a specific.
Safety Stuff: The material contacting the juice would be ceramic... certainly more safe than contact with the nichrome and solder.... the statement about no leaching of material should satisfy the concern.
Size, design, airflow: to be taken into account when designed (discussion so far indicates a replacement atty, so this should be included so a direct replacement can be realized).
Durability: MTBF = 10,000 hrs. Ceramic should be more durable than what we are currently dealing with.

I am trying to keep track of the reason for encapsulating the coil in the first place, i.e. the main failure is due to contact with the juice. These rods seem to address all of the concerns with the current material.
Are there concerns that we have not heard yet? If anyone is concerned, now would be a good time to make those thoughts known.

 

[roadkilldeluxe]

Alternative #1 is my idea of an efficient and simple atomizer. Everything beyond the heating element (electrical,batt) is completely blocked off from the liquid. Air intake is right next to the heating surface.

Alternative #2 I threw in just to keep ideas flowing. It should be compatible with most models with minimal modifications.

I have used cone-shaped filler/wick because I think they balance minimal contact w/ heating surface and wicking capacity very well. The area that touches the heating element is very small, yet re-wets instantly because of the large cache of juice right behind it.

Are there concerns that we have not heard yet? If anyone is concerned, now would be a good time to make those thoughts known.

I'm having a hard time coming up with any reasons that Nichrome would work better. Exposed Nickel, Chrome, solder? Bleh. My main concern at this point is its efficiency. We now know these elements are capable of extreme temps, but how will they perform under wimpy 3.7V batteries?

edit: here's a template of a 510 atomizer+cartridge if anyone wants to draw up some diagrams. It is roughly to scale. 10 pixels = 1mm

 

[Scubabatdan]

here's a template of a 510 atomizer+cartridge if anyone wants to draw up some diagrams. It is roughly to scale. 10 pixels = 1mm

Thanks for the template, here is my idea, use a cone shaped design the allows for a place for the fluid to pool in the hotter section. With channels cut down the side air will flow up the side of the atomizer and drawing vapor out. The contacts on the bottom would make for a direct replacement with no soldering. If they can make the mold, they should be able to make any design, why not use a resivor design closes to the hottest part. And if the can make a cold section at the tip then this can touch the wicking material with out melting or burning it. Anyway here is my idea:

I will work on some 3D pics, in LightWave
Dan

 

[jacko]

Excellent ideas. good job.

 

[Quit4myKids]

I go away to spend the day with my kids, and you guys have been all over this!

Dan, you are a genius, and I think your idea is inpired, but the form factor has to be a simple rod. These guys don't have the facility to do anything else (another company might, but I haven't been able to find anyone that specializes in micro-ceramics that product anything cost effective. This heater isn't a coil, it's a flexible circuit that is printed to match our specification for voltage, ohms, etc..., then rolled up and encased in the ceramic material. Since they cannot make it any shorter than 10mm total, and it's a rolled design, we can't do anything fancy like shaping the tip. Making it fit exactly in the atty tube isn't a good idea, since the heater would simply heat up the tub, and not the juice. We have to insulate the rod from the tube, and are pretty much stuck with the rod shape. I really like the reservoir idea, but I'm not sure how we could do it while still insulating the outside tube, unless there is a non-porous ceramic that insulates, rather than conducts heat. I really like you last drawing with the template. If we can find an insulating ceramic, and cast it around the heater, I think this is the best design. I suggest channelling the airflow all the way to the bottom of the tube (I know I said this was a bad idea before), because the sloped sides would prevent leakage into the air passage, and what little did get in would be cleared by the next draw. The only problem I could forsee would be placing the e-cig on it's side, and excess liquid pooling on the side and seeping out. I think that would be a very rare instance, especially if there were numerous small tubes, rather than a few larger ones.

I also really like your idea of eliminating the leads, and just pressing the heater in using the pads as connectors. Perhaps the best way of doing this would be to cast the leads in ceramic pot directly into the base connector, and press in the 4mm heater into the connector. This inspires another idea regarding fluid delivery if we can't use an insulating ceramic, but I'm exhausted, and want to explore it further before commenting publicly.

Jacko, the heater isn't a coil (see above paragraph), so it must be encased. Otherwise, I see your point, and agree in principle. Keep the ideas coming!

Roadkill, you also are amazing. You obviously are quite knowledgeable about much of this, and a great asset to the effort. I love your drawings. #2 is ideal imo, but short of an exposed coil, we will not likely find a replacement heating unit this small (1mm x 4mm rod) that will work for us and be reasonably priced. The only vendor I could find that was even capable of this said he wouldn't be able to do large production runs for less than $350 USD each, as these would be highly specialized items. Everyone else laughed at me. Plate heaters just aren't made small enough to fit our atty connector, so they aren't an option either, unless we want to deal with a big, hot bulge in the middle of the atty tube.

Thanks to everyone who has commented on this, and provided encouragement. With some perseverance, I think we may have a winner here! Sorry, I haven't responded to PMs, I'm not going to take any money until we have a workable design spec for the heater, and are ready to place the order. I'm hoping with everyone's help that this can be early in the week, perhaps Monday or Tuesday. We can only get 10 heaters in the sample run, since they are going to be hand fabricated and casted. Hopefully that will be enough for everyone with a workbench and the desire to experiment. I'll be back late tomorrow to see the progress.

You guys are awesome!!

Q4mK

 

[Shining Wit]

1) Boiling point of VG is at or slightly below 200C, I believe. Having a little bit of water in the juice will lower the boil point by a decent amount, I would almost think that you would want to aim for ~160C at least, and 100C i'm not sure would work at all. Is the quoted temp the internal coil temp or outer surface temp?
Boiling Point of VG is around 290 degrees C, the same temp as it starts to degrade and a major factor in our testing ECOpure liquid to over 300 degrees C.
2) Safety--what material exactly are they using? What chemicals will the liquid be exposed to? Is the nichrome welded or soldered? What are the leads made of?
Lead-free solder and high temp ptfe coatings have been around for some time now.

Thanks to everyone for some very interesting posts on this topic.
It's so refreshing to see vision and sense linked so closely in this type of R&D,
rather than the 'boil in the bag nicotine extraction methods'!
John.

 

[jacko]

I envisioning re-using the same ceramic pot, wrapping the entire heating rod in a 1mm thick stainless sleeve, and it would fill the ceramic pot. A 10mm heater would bring the tip to the exact position of a low bridge 801 atty, and an 11mm heater would match a high-bridge atty, such as the bestecig.com BE112 attys that so many folks here (including myself) love so much.

I like where you were going with this. It seems reasonable to me that we can use an inexpensive (compared to custom engineering) that they can sample quickly, and test the concept. If we want these 'plug-and-play' then maybe Quit4myKids Had the right idea from the beginning... plus some press fit connector. I think it would be a lot easier to work with if we had a unit to work with.
What do you think? It seems that the original concept was to get away from the exposed coil (I realize that the rods do not have a coil) and the rod eliminates the coil design. would this give a long lasting heat source with current e-cig parts? Should we get this concept proven and then move ahead with the ultimate dream machine, or should we incorporate everything into this trial?

 

[stroh22]

Count me in as well, I'd like to help (with costs). I'm not too technical with the workings, but I can surely try. I PM'd you Quit.

 

[roadkilldeluxe]

I also really like your idea of eliminating the leads, and just pressing the heater in using the pads as connectors. Perhaps the best way of doing this would be to cast the leads in ceramic pot directly into the base connector, and press in the 4mm heater into the connector.

Have you seen how mini christmas lights plug into the strand? It's almost like what you are describing here. That would be really convenient on a heating element.

we will not likely find a replacement heating unit this small (1mm x 4mm rod) that will work for us and be reasonably priced.

The heating elements in my designs were real rough sketches. I used a scale of 10px = 1mm, and so the bottom design is actually 12mm long and 2mm thin (which is too thin, but it was just a quick sketch of the concept).

The middle drawing, Alternative #1, doesn't have to have a heating rod as thick as the housing. It could be a thin element with insulation blocking the outside. It will definitely need to be longer than shown in the diagram, though.

Here's another take on the same design (this one has a 4mm x 10mm element):

One of my highest priorities for a design is having the location of the vapor production right inside the airflow path. As you can see with this design, the vapor gets swept away instantly because it is directly on the path. I think it might not be crucial to completely seal off the entire bottom, except for waterproofing reasons. It shouldn't interfere with vapor production as the hollow part on either side of the element is out of the airflow anyway. We could just fit a thick o-ring near the bottom of the heating element to keep liquid from coming out the bottom.

 

[Scubabatdan]

Well here is version 3, using a standard rod version. If we can find a place to make the ceramic inserts the rod will fit into, then we can shield its heat from the external case and use the rod itself to wick the fluid straight down into a resivor similar to my previous version. By keeping everything else the same ther are less modding required as far as the cart and batting material is concerned. Again by canneling the air up the sides and then into passage ways to the interior conture the risk of leakage is minimal, also it moves the air flow closer to the point of vaporization. I dont like the airflow down the center as there is to much chance of fluid being suck into the users mouth, also we would have to resdesign the cart and material.

Well here is the design:

Dan

 

[SurfVortex]

Brilliant Everyone!!!!!!!!!!!
How would these rod heaters work with 5 or 6 volts? Would the chip inside just keep the output steady? Would we need separate heaters designed for different voltages?
Please count me in, I have pm'd you Q4MK.
Thanks,
SV

 

[Ralph Hilton]

I didn't get the idea that there is a chip inside. The way it was described suggested to me that it was an electrical circuit that varies in resistance at a much higher rate than nichrome which would rapidly limit the heating power. The characteristics could be changed by using different metal alloys. A dry nichrome coil goes over 500C quite rapidly whereas it looks like these would not.

 

[caesar]

With current atties, when you take a draw, small droplets of e-liquid are drawn from the metallic wool through the hole in the center of the ceramic pot on to the hot nichrome wire.

If the nichrome or any other heating element would be pooled with liquid, it wouldn't have the necessary heating power to vaporize the liquid.

I envision a hole in the middle of the heating rod to allow the air to draw the same small amount of liquid onto the hot part as in regular atties. The steel wool and bridge will have to be moved higher (~7mm higher - 10mm in ceramic heater compared to ~3mm with the usual nichrome wire). So carts will have to shrink too or be used for dripping.

Just my 2c.

 

[jacko]

That design looks nice Dan. I was thinking of how to shield the outer case, the ceramic with a hole in the center looks promising. I have some ceramic pieces that are cylinder shaped and have a hole in the center but I haven't measured them. The O.D. is 10.5 mm and the I.D. of the hole is 5.5mm. I wonder if I could grind them down to make them work. I need a sun rod to find out, I guess.

 

[Bubo]

This may be an esoteric question at this point - but does anyone know how much air is being allowed through current atomizers now?

My 510 has three holes, the center one is 1.5mm and the two sides are .75mm each (eyeballing it with a ruler) googling how to find the area of a circle, I get 2.651 square millimeters of area to let air in...

I assume that this has something to do with the draw (to simulate a cigarette's draw....)

Just a thought to put on the back burner...

 

[roadkilldeluxe]

This may be an esoteric question at this point - but does anyone know how much air is being allowed through current atomizers now?

The amount of air being let in is about the same as how much you inhale. Try blocking all the holes on the outside of the ecig and see how hard it is to actually inhale. The actual volume of gas ("vapor") is pretty small.

I dont like the airflow down the center as there is to much chance of fluid being suck into the users mouth, also we would have to resdesign the cart and material.

But isn't that how cartomizers work? People are always saying they taste great, and I have never heard problems with fluid leakage. I was trying to replicate that sort of design. (Disclaimer: I have never actually used one. I could be completely wrong )

You are right about the redesign, it would be nice to avoid that.

If the nichrome or any other heating element would be pooled with liquid, it wouldn't have the necessary heating power to vaporize the liquid.

This is true, hence why I have been using a "cone" shaped filler material in my diagrams, to limit the amount of liquid touching the element at any time. I kind of doubt we could get the manufacturers to put holes in the centers--it sounds like that space is being used up by the element and "circuitry" inside.

 

[Bubo]

RoadKill - PM sent (To keep the thread on topic!)