Vamo Spring Resistance

[Robby]

Hi, Charlie here. I've posted some pics below of readings taken earlier today of 1) the replacement springs sent by the Vamo manufacturer in Jan 2013 (reading 0.5 ohms, deduct probably 0.2 ohms for the leads) and 2) readings taken from the top of the spring to the end cap on a V2 Vamo supplied in December 2012 which came in slightly lower (!!) at 0.4 ohms, so probably about 0.2ohms taking into account the leads.

Vamo spring/end cap as supplied Dec 2012

Replacement spring supplied 10.01.2013

I'm not a qualified electrical engineer, but can understand that if the resistance of the spring is approaching or higher than the atomizer, it will heat up causing battery drain. However, even cheap torches from the pound shop have cheap low res springs and don't seem to have these issues, so it's hard to imagine even the cheapest conductor spring would have any noticeable resistance. I'm wondering if we're having problems with multimeters that are struggling to pick up a very low resistance. In the pics taken above, the multimeter was set to its lowest ohm setting between 0-200 ohms. If the resistance of the springs is below 1 ohm (which as a conducting spring it really should be!!), a mutlimeter set to read between 0 and 200 ohms is going to struggle detecting ohms in the 0 to 1.0 range. Could this be a possible explanation, if not of the vamo problems, of the difficulty in getting accurate readings?

Here's my investigation so far: The first time I checked the resistance of the spring was when jrob3rts contacted me and then sent the photos posted at the start of the thread. So I did exactly the same test with a £30 multimeter (made for car electrical testing). I got almost exactly the same 'high and flickering' result documented above. I have this on video, but it is exactly as described above. The resistance readings kept swinging all over the place. Very odd I thought - how can the resistance change? So I checked and rechecked the connections etc. Totally perplexed I called my father in-law who, unlike me, is an electrical engineer who worked for decades in research.

So this afternoon we finally tested the springs again using a few different multimeters and at first result was the same as jrob3rts test, and also in my own tests. High resistance (eg over 5 ohms) and flickering all over the place. We then tried another multimeter (he's got a few, lol) and the readings stabilized (see photos above). Our initial views are that the mutlimeters we used first were not made to measure very low resistance. In theory, these are conducting springs so should have as little or no resistance as possible. Could it be that the ultra-low resistance is beyond the measurability of many domestic multimeters?

Clearly the spring issue is worrying a lot of people. I sold out of replacement springs in a matter of hours - don't worry jrob3rts I've put one aside for you

I will email the factory now asking for more springs and giving them the link to this thread. They told me they are following the issue on the forums.

Not sure our findings today really get to the bottom of this and I'm sorry if they cloud the issue. I'm just as curious and keen to get to the bottom of this as everyone else. So I'll be following this closely and hoping for a better understanding of what is causing problems.

jrob3rts: if the replacement spring (will send out tomorrow) doesn't fix the issue, lets get it back to Vamo asap so they can get this sorted asap.

Hope this helps.

I think the meters are fine, I have a few different ones I use here as well. The best way to do it is to short out your leads and write the reading down, then measure the resistance of the spring again and subtract the reading you got from the leads alone. It doesnt really matter how much you paid for you meter, with a target resistance this low(less than 4 or 5 ohms), you should always do this to get an accurate reading. My belief from all the pics I have seen is that the springs that people have been purchasing privately are the same kind of metal ie steel (they have to be to get the springyness) then copper plated. Copper is the best generally available electrical conductor there is. The wandering reading that you get when trying to read spring metal resistance is not unusual, it is so difficult to get a good reading from the one tiny spot that the lead is connecting too. What I have on the end of my leads are sharp croc clips, so they get the best connection possible.

 

[Robby]

I should say that if you have a automatic zeroing meter, you shouldnt need to subtract the "leads only" reading as it is already taken care of for you. I am an electromechanical engineer by the way, I have been at this game for 40 years now as a field service engineer.

 

[Robby]

Just made another interesting discovery, if you get some very fine abrasive paper (I have some wet and dry) and give the top and bottom of the spring a quick rub across the contact area, it is much easier to get a steady reading. I have three meters here, A Fluke meter and a couple of cheap ones (one was £3 shipped off Ebay lol). I am getting virtually the same readings off the three of them and it is steady, even without the croc clips. It could be that there is some sort of coating there, maybe even oxidisation. That wouldnt surprise me as to produce the spring, they may have been heat treated and annealed.

 

[Robby]

It would be great if someone who has the new one coming could try cleaning the contact area on the dodgy one with some abrasive paper (wet and dry) or even a brillo pad, it did actually make a slight improvement in the smaller springs. I discovered as well that even the two smaller springs I have looked at today are not the same phsically. The original one (rubber buttons) is not as long as the one in the Black Chrome model, the plot thickens lol. When you think of it, we use oxidation(same as rust) in a positive way when we oxidise our stainless steel wicks. What we are doing then is creating a layer of insulation so that the coil doesn`t short on the wick. It wouldnt take much oxidation to cause the problem that we are getting on the springs. Who knows, a quick rub down with a Brillo or some wet and dry might reduce the problem considerably. The amount of oxidation that would be enough to create this problem may not even be enough to be visible to the naked eye.

 

[Robby]

Another thing that helps considerably when taking a reading on these springs is to rub bit of Vaseline over the top and bottom of the spring at the contact point. You dont need a lot, you dont even need to use so much that you can see it, but it makes a big difference when taking a reading. It will have the side effect of keeping the contact area cleaner as well. How much difference it could make on it`s own, I dont know as I dont have the big faulty spring. Be interesting to find out though.

 

[Charlie]

SAFETY WARNING – VAMO V2


Some Vamo v2 users have had issues with their springs heating up. This has been discussed on the forums already.

I would like to advise Charlie’s Vape Shop customers that if you have a Vamo V2 that is heating up, please DON’T USE IT.

If it is hot to touch, it is NOT SAFE to use. Even if it is only getting warm, I would still advise you not to use it.

The manufacturer has acknowledged this problem and will be sending out gold plated springs. I should have these new springs in stock next week.

Here is a picture of the replacement spring for Vamo V2.

[URL="http://i48.tinypic.com/a1svg4.jpg%5b/IMG"]http://i48.tinypic.com/a1svg4.jpg[/IMG[/URL]]

So if you bought a Vamo V2 from Charlies Vape Shop Ltd and the base spring is heating up, please contact me and I will send a new spring out next week free of charge in the hope this will fix the problem. The Vamo’s come with a guarantee, so please rest assured the problem will be rectified, or you will be entitled to a full refund including postage etc.

The manufacturers say they have now repeatedly tested the new spring and that it fixes the problem.

Therefore if you like the Vamo and want to keep it, but it is warming up, please put it to oneside and I will get the new springs to you asap. If you are prepared to wait a few days for a new spring, it sounds that the spring issue can be easily fixed.

We have temporarily withdrawn the Vamo from sale until we can send Vamos out with the new spring. Since eCigs are a relatively new device, I don’t think we can be too careful when it comes to safety. I’ve heard that the device would have to heat up to the point where it was too hot to touch to risk the battery catching on fire etc, but I still recommend you don’t use it one side if it is generating on a small amount of heat from the spring.

If you have any questions, or concerns, please email via [URL="http://www.charliesvapeshop.co.uk/"]www.charliesvapeshop.co.uk[/URL], either using the contacts form or email address given at the top right of the page.

I will post updates in the coming days with any new information I get. Also, if there is a safety warning area of the forum and I have missed it, can someone please let me know.


PBusardo has posted the following on his website:

[url]http://tasteyourjuice.com/wordpress/2013/01/07/the-spring-has-sprung-warning-potential-vamo-spring-issue/[/url]

THE SPRING HAS SPRUNG – WARNING POTENTIAL VAMO SPRING ISSUE!
Let me start off by saying this…
Attention Manufacturers… PROPER TESTING WILL AVOID SUCH ISSUES!
Thank you.
Ok, here’s the deal. The Vamo has a potential spring issue. The one I used in the review had, what I believe, was the original thin spring. Note that I did not, nor do I receive ANY heat from the bottom cap.
People were having issues with that spring (rattly batteries) so they replaced it with a beefier one. That spring may have an issue.
Is yours effected? I honestly don’t know. The post was found on Health Cabin relating to what they call the Bamboo which is a Vamo. Could the issue just be related to units purchased there? Again, I don’t know. I’m just passing along what I’ve heard.
This is one of the problems with all these versions and revisions coming out without proper in-lab, alpha, beta, and field testing and it really needs to stop. A properly tested and rock solid device should be far more important than rushing something to market.
So… if you are experiencing ANY heat from the bottom cap… STOP USING IT and contact your vendor regarding the issue.

Here is the post as seen on Health Cabin…Dear customers,
We are very sorry to inform you that we discontinue selling eGo Bamboo APV(Stainless/Chrome/Black Chrome) for a while because the big wide spring in the cap has big resistance, which makes the Bamboo cap very hot when Bamboo is working, especially when Bamboo works at a high Voltage or Wattage with a low resistance atomizer. We are working on new good springs with low resistances and expect to get new springs ready in some days.
We will resume selling the products and their caps when the new springs are ready.
If you have Bamboos with the wider big wrong springs, please stop using the products and contact us by ticket system.
We are very sorry for the inconvenience.
If you have any questions or need any assistance, please feel free to let us know by using Help Desk and submiting a ticket.
We look forward to always being able to serve you better.
Health Cabin

 

[jrob3rts]

Just a quick update.
I received the replacement spring from Charlie earlier in the week.
Sadly my Carto is duff in terms of flavour so have not had a change to try using a like for like top end.
I'll update once I get some new Cartos to try.

 

[Charlie]

Replacement springs should be in tomorrow/Thursday (have been processed at Heathrow). Will be sending these out asap.

Jrob3rts, you'll still need to put the gold coloured spring in, it's different to the first replacement I sent out, these springs that are coming are different again. We'll get there!

The first replacement was the same V2 spring, since some of these weren't causing problems I thought it worth trying. But it sounds like these springs coming tomorrow will sort out the problems. Fingers crossed!

 

[jrob3rts]

Hi Charlie,
I did wonder if it was the same as it looks near identical.
It did read a lower resistance but it was still pretty high at about 0.4 to 1.something.
I am waiting delivery of some Cartos anyway to try but the one I had did seen to cause the bottom of the vamo get warm again (though not as warm)
Will await the swanky gold jobby.
James

 

[Ssscrudddy]

My Vamo is a V2 (direct from China Zainy.net), but with the small spring that needs to be stretched for 18650 mode. My Vamo gets warm all the time.
But it isnt the spring getting warm or hot.