The Nomad From Morwood

[natural farmer]

I don't need any hype! Just send me a Nomad!!! Hahaha

 

[GreenHopper]

Dan's on the case.

He's currently gearing up for production of the first run which takes a bit of time and a lot of attention.

This is the calm before the storm, there will be Nomads everywhere soon

 

[Mr. Me2]

Hey @Dan Morrison - I just saw this on the firewood thread:

Firewood Customer,

PLEASE STOP USING YOUR FIREWOOD 4 IMMEDIATELY!

This notice is being sent to inform you of a serious safety issue that has come to light with the Firewood 4 vaporizer. There was an incident where a battery vented and caught fire immediately after the battery door was closed on the unit. Fortunately there were no injuries, but a serious safety risk still exists.

Thought you should know about this just in case you are using similar technology in the Nomad (since both are handmade wood vapes).

Better safe than sorry!

 

[ZC]

I don't know the details of the FW4 failure but I know the design is different. The unit turns on as soon. As the battery is inserted and there is always a completed circuit.

With the nomad there's no completed circuit unless you're pressing the button. I think it's unlikely that the nomad could possibly have the same issue. It could still potentially vent a battery, but only from abuse like over draining the battery.

 

[KeroZen]

Until Marc releases more details the information is not useful, we already know that Li-Ion batteries are particularly unsafe by nature, some chemistries more than others but even LiFePo can go wrong.

As a periodic reminder to all our members >> http://fuckcombustion.com/threads/18650-battery-safety.18527/

For the Nomad I already told Dan that having the cell positive terminal facing down (outwards) was not a good idea, especially when the springy bridge can grind the cell close to the top insulation ring. Lazy users will not lift the sprong when doing and undoing it, and if the shrink wrap insulation shears at this location it can be quite bad.

Unfortunately, as the Nomad is designed it will be more efficient to use it this way with a big beefy ground in the form of the bottom copper plate.

For the FW4 we can only guess at this point, but it could be the problem I described above. Or a crappy cell... or a fault in Marc's circuit and/or code...

 

[marduk]

For the Nomad I already told Dan that having the cell positive terminal facing down (outwards) was not a good idea, especially when the springy bridge can grind the cell close to the top insulation ring. Lazy users will not lift the sprong when doing and undoing it, and if the shrink wrap insulation shears at this location it can be quite bad.

I saw a post on an e-cig forum that the better battery orientation design for safety was (+) toward the heater and (-) toward the switch. Isn't that the way the Nomad is laid out?

 

[XiolaOne]

has a price been mentioned yet?

 

[marduk]

Undecided on final price/discounts..etc..


Rough estimate, yes. Somewhere around $275 usd.

 

[KeroZen]

I saw a post on an e-cig forum that the better battery orientation design for safety was (+) toward the heater and (-) toward the switch. Isn't that the way the Nomad is laid out?

The problem is not the circuit itself, it's having a moving contact grinding on the positive side. In fact the circuit wouldn't exist, the contact alone would be enough to create the short on a cell with damaged wrap/insulator.

Let's not forget that these cells are absolutely not meant to be used the way we do. This is why at some point people thought that Sony stopped production, but in reality they didn't. They just started selling only to OEMs (power tools, laptops, e-bikes etc) to be used as part of battery packs with a protection circuit.

This is also why Imrbatteries.com is displaying a similar warning. Nobody wants to be involved with accidents and they are bound to happen with this design. When you use button top cells (i.e. protected) the problem doesn't exist. Same when the cells are assembled inside a pack with spot welded tabs and a BMS circuit.

We're playing with fire here (pun intended)

 

[little maggie]

The problem is not the circuit itself, it's having a moving contact grinding on the positive side. In fact the circuit wouldn't exist, the contact alone would be enough to create the short on a cell with damaged wrap/insulator.

Let's not forget that these cells are absolutely not meant to be used the way we do. This is why at some point people thought that Sony stopped production, but in reality they didn't. They just started selling only to OEMs (power tools, e-bikes etc) to be used as part of battery packs with a protection circuit.

This is also why Imrbatteries.com is displaying a similar warning. Nobody wants to be involved with accidents and they are bound to happen with this design. When you use button top cells (i.e. protected) the problem doesn't exist. Same when the cells are assembled inside a pack with spot welded tabs and a BMS circuit.

We're playing with fire here (pun intended)

So are you saying that the battery operated vapes with flat topped batteries are all unsafe?

 

[marduk]

The problem is not the circuit itself, it's having a moving contact grinding on the positive side. In fact the circuit wouldn't exist, the contact alone would be enough to create the short on a cell with damaged wrap/insulator.

I see what you're saying... I went back in the thread to refresh my memory and found the info quoted below. It seems to me that based on the geometry shown in the photo, and Dan's comments about tilting and pressure, that the moving contact wouldn't really be "grinding" against the critical area. I believe the moving contact would only lightly rub against the wrap and shouldn't really cause any damage since it is rounded on the bottom.

My reasoning is this: the distance between the bridge's swivel point and the HM contact is shorter than the distance between the swivel point and the battery contact, and the bridge battery contact is twice as wide as the bridge HM contact. When you swivel the bridge, the HM contact point will completely disconnect and drop down before the battery contact point reaches the critical wrap area. The tilt will relieve the downward pressure at the battery contact so when it goes over the wrap it's more of a "brushing" or "rubbing" rather than a "grinding" that would wear out the wrapper. So I'm comfortable with the design. Of course, I'll be watching the condition of my batteries like a hawk, because I'm not one to tempt fate.

The tension adjustment screw, shown here in brass, is only used for adjusting the pressure of the contacts. It doesn't spin with the bridge, so the threads will not wear quickly. In any case, the threads go deep into the main body with a steel thread insert. So the brass screw will wear before the steel thread, and then can be easily replaced.

Because the downwards pressure of the screw is applied at the center point between the two contact pads, the two contact spots work against each other to evenly distribute the force... And if one battery is a bit taller than another, the bridge is able to tilt slightly and still give equal solid pressure on both contact pads.

Also shown here is a verawood spacer/insulator under the bridge screw, but this will most likely be black Delrin or African blacwood in the production units.

Now I just have to finish the sleeve and bottom plate and we're pretty much there!

 

[Fat Freddy]

Perhaps @KeroZen and/or other knowledgeable members could enhance my (our) understanding on conditions in which a short can occur. For instance, I've been under the impression, with my limited understanding of these batteries, that simply having a torn battery wrapper will not necessary cause a short but rather the metal battery casing at the site of the torn wrapper has to be exposed to a material that will allow the interruption of the normal circuit between the positive and negative terminals. As an example, a battery with a torn wrapper in one's pants pocket, along with some quarters and dimes, COULD be enough to short the circuit. Yes? No? And even in that scenario, again with my limited understanding, the battery would not necessarily vent with fire immediately but likely begin to produce enough heat that one would feel it first. However, in the scenario we are considering with the FW4 I'm confused as to where the additional metal comes in to play to cause a short circuit. Is it simply at the top edge of the positive terminal where it gets worn/torn with repeated removal and installation? And is the battery compartment air tight enough to cause venting with fire, or worse? Would a few air holes drilled in the battery cover be sufficient to alleviate any concern for an explosion? Maybe some of our resident gurus might weigh in here?


.

 

[KeroZen]

So are you saying that the battery operated vapes with flat topped batteries are all unsafe?

No, I'm saying these battery chemistries (variants of Lithium-Ion) are unsafe by nature. You should always be careful during handling, use, storage and charge.

That's the price to pay if we want power and it's the best available today. Next technology might be better, it's supposedly around the corner... but it's been quite some years already and we're still waiting, not unlike nuclear fusion...

Note that it will likely be a revolution and the stakes are very high (notably electric cars becoming mainstream, so there's a lot of money at play, both to be made and to be lost, by oil companies and producing countries, but let's not get political here!)

Mass-produced vapes using 18650's should be fine. Their contacts are precision machined by robots and are very smooth. They also have to get through the whole certification process to be able to enter the US and EU markets. So for instance your Tubo being based on the joyetech evic VTC mini, or other Chinese-made vapes like the X-Max etc should be ok (note that I always insert the positive side first in my evic and other mods such that it's the negative side that grinds on the contact though)

It also greatly depends on how the contact is designed. If it's a door or something you screw it's less problematic than something that slides and grinds.

For your other vapes: I always have the negative terminal facing up in my Milaana. Again grinding on the negative terminal is completely safe, it's a solid flat piece of stainless steel, it's the other side that is delicate. In the MVT the door slightly grinds on the positive, so I took the habit of pushing the cell down with the tip of one finger while sliding the door. The pressure is small and the contact is round but better be safe than sorry (I told Dave to consider reversing the cell polarity, but as is you can't just insert it backwards as the MVT touch switch is polarity sensitive)

Just watch your cell wraps closely and if they get damaged at the top (anywhere else is harmless) bring them to a vape shop to get them rewrapped (or order a wrap kit from the place you got your cells from, it's easy to do)

It seems to me that based on the geometry shown in the photo, and Dan's comments about tilting and pressure, that the moving contact wouldn't really be "grinding" against the critical area. I believe the moving contact would only lightly rub against the wrap and shouldn't really cause any damage since it is rounded on the bottom.

Yes that's a possibility, but why not eliminate the risk altogether by inserting the cell the other way round?

In its current form the cell can go both ways. My remark about the beefy ground is just the normal practice as everything converges to that part, but here the circuit is super trivial and only a single path flows through. I can't comment on your remark about having the switch high side or low side, maybe it makes a difference in practice, I don't know. With MOSFETs it makes a clear difference but in a mechanical-mod configuration like this I'm unsure.

Perhaps @KeroZen and/or other knowledgeable members could enhance my (our) understanding on conditions in which a short can occur.

It's simple, look at this picture:

The entire cell shell (the can) is negative, meaning the bottom, the sides and up to that shiny rounded lip (the upper-most that is, including the "rings" below) Then the brown part is insulation and the raised center post is the positive terminal.

When the cell is wrapped it also has an (usually white but can be black) extra insulation ring above the brown part. This ring can get dislodged when the wrap is damaged, as it's just floating and held "sandwiched" by the wrap.

All you have to do to short the cell is connect the lip to the center post, and they are a few mm apart in a straight line. A key could be enough, like in your pocket as you said (hence the need to always carry them in the provided plastic case. If you don't have those, no excuse they are worth cents only on aliexpress!)

Indeed when you short the cell it heats first and does not necessarily enter the thermal runaway mode. When it gets past 120°C or something it will start venting. Normally only hot gas and nasty boiling chemicals (awful smell) and in the worst case it can even catch fire (less likely with IMR/INR than the so called "Li-Po" soft pouch ones as found in cell phones and remote control stuff)

 

[Dan Morrison]

Man, I feel so bad for Marc, I know that in his shoes I would be freaking out. My worst nightmare would be to have someone get hurt using something I made...

Seems as though he is handling it as best as anyone can.

And yes, the Nomad is a completely different design.

Unless you're actively pressing the fire button, the unit is always off, with a completely broken circuit.

My reasoning is this: the distance between the bridge's swivel point and the HM contact is shorter than the distance between the swivel point and the battery contact, and the bridge battery contact is twice as wide as the bridge HM contact. When you swivel the bridge, the HM contact point will completely disconnect and drop down before the battery contact point reaches the critical wrap area. The tilt will relieve the downward pressure at the battery contact so when it goes over the wrap it's more of a "brushing" or "rubbing" rather than a "grinding" that would wear out the wrapper. So I'm comfortable with the design. Of course, I'll be watching the condition of my batteries like a hawk, because I'm not one to tempt fate.

This is exactly correct, and one of my main reasons for the swivel point in the place that it is. When you swivel the connector bridge, the pressure is not only relieved from the battery side, but the bridge is spring loaded so that it will keep itself lifted up. Since the positive plate is a hair taller than the wrapping, the bridge will glide over top of the wrapping without touching it.

@KeroZen, IMO, the vented end should face out so that it has room to offgas in the event of a meltdown.

As it stands, I think that people will just need to be careful to not use a damaged cell. I can't imagine any situation or vape design where a battery is safe without the wrapping/paper washer intact.

One good thing about the battery being exposed on the end is that it's always very visible and easy to see that it's in-tact. It'd be tough to miss any major damage.

 

[KeroZen]

On a more positive note, here are a couple pictures of the new Panasonic 20700 cell, for size comparison with 18650:

The weight difference is clearly noticeable.

 

[GreenHopper]

Man, I feel so bad for Marc, I know that in his shoes I would be freaking out. My worst nightmare would be to have someone get hurt using something I made...

Seems as though he is handling it as best as anyone can.

And yes, the Nomad is a completely different design.

Unless you're actively pressing the fire button, the unit is always off, with a completely broken circuit.



This is exactly correct, and one of my main reasons for the swivel point in the place that it is. When you swivel the connector bridge, the pressure is not only relieved from the battery side, but the bridge is spring loaded so that it will keep itself lifted up. Since the positive plate is a hair taller than the wrapping, the bridge will glide over top of the wrapping without touching it.

@KeroZen, IMO, the vented end should face out so that it has room to offgas in the event of a meltdown. I also need the large flat surface to be in contact with the button terminal.

As it stands, I think that people will just need to be careful to not use a damaged cell. I can't imagine any situation or vape design where a battery is safe without the wrapping/paper washer intact.

One good thing about the battery being exposed on the end is that it's always very visible and easy to see that it's in-tact. It'd be tough to miss any major damage.

I think it makes sense having the battery venting end facing away from the users face.

 

[Dan Morrison]

@KeroZen , I just tried the battery with positive terminal facing inwards. Performance feels the same, as I would suspect. I'm not sure why I never just tried this... for some reason I had it stuck in my head that is HAD to be positive side up to function.

It makes no functional difference whichever way the batt. is inserted.

I would say that it could be up to the customer which batt. orientation they feel more comfortable with... but I also think it's a responsibility of the maker to recommend the best/safest usage instructions... hmm..

I'll have to think more on this...

p.s. - Thanks for the new battery pics! I can't decide how I feel about the size difference, hahah. On one hand.. it's only a tiny bit bigger... on the other.. it's so much bigger!

 

[grokit]

With the milaana I'm pretty sure that it's recommended negative side out to make the best contact.

 

[KeroZen]

@Dan Morrison : too late for the Nomad v1 anyways! Let's wait for the new LG/Samsung cells and keep the idea under the carpet until v2 or next product.

I would hate to cause any delay in production. I think I never awaited any vape so anxiously...

For the cell polarity, with such a large air intake on the bottom of the Nomad it should vent freely whatever the direction, *I think*. The only way to know for sure would be to destroy a Nomad and a cell... If you do, make sure to record a video as it could be used as evidence that you performed worst case scenario tests (could be useful someday to get certifications etc)

It's more of a problem with metal tubes like those cheap mech mods where some only have a few meager holes at the bottom. They are almost completely air-tight and create a pipe bomb.

While I said above that the X-Max V2 should be safe as for its contacts, it's creating the aforementioned situation unfortunately (and it's even worse in the Herbstick Eco) There aren't enough holes and they are on the opposite end of the positive side.

 

[grokit]

I would hate to cause any delay in production. I think I never awaited any vape so anxiously...

What kind of additional wait would we be talking about here, theoretically ?

 

[Dan Morrison]

Alright, well, the day is upon us!

I will be announcing the pre-orders today via the mailing list, with all the order details, prices, options, etc...

You'll have the weekend to think it over, and on Monday I'll be filling the pre-order list.

I will be taking about 25 pre-orders.

With a ship date 3 months from now.

One small change has been made. I was thinking that bronze wouldn't be as nice as sterling silver, for the exposed metal parts... but now that I've lived with the bronze prototype for a while, I actually prefer bronze. Functionally the two metals should be the same, but aesthetically I like the bronze for it's near endless patina possibilities. With silver, you have only three options, silver, black, gray.

Of course all of the Heater Module components, and electrical contacts will be solid sterling silver or Stainless steel (I actually really like the qualities of Stainless for the Heater Module shell, it doesn't suck away heat as much as silver). No bronze in the air path. All bronze will be ROHS compliant lead free.

Here are the newest images of the production model.

Looking down the stem, you can see right through the entire airway. Pretty cool.

 

[RelaxedNow]

I'll be checking my email frequently.

 

[Mr. Me2]

Wow

 

[invertedisdead]

Combustion fuckingly sweet, Dan!

 

[KeroZen]

I, for one, welcome our new lichen overlords!