Multimeter Confusion in Paradise

[tA71ana]

I have recently started doing atomizer rebuilds.
So far I have rebuilt the coil on my Vivi Nova. The first one was terrible..it had a short and the resistance was too low.
not to be easily sullied, I built a second coil; this one was much better. it came out at 2.6 ohms.
This is the issue:
I got an Excel XL830L multimeter and after watching YouTube vids I fired it up and tried to test my ohms on the first and second coil I built and the reading kept jumping around. I have never used a multimeter before and I know this has got to be user error.
I did the following:
Read the instructions, lol
I attached the black lead to the COM and the red lead to the V (ohm) mA.
I turned the dial pointer to the 200 marker within the OHM area of the dial .
I tested the internal resistance of the meter so i could subtract that from the total ohm reading after I determined the resistance of the coil.
I took a cartomizer to test..I knew the resistance on it was 2.5.
I put the red lead into the bottom of the carto and the black lead against the threads (that's what it looked like on Youtube) and...

It jumped around so much I couldn't tell what the devil the resistance was, lol
Tried several times..same result.

What I finally wound up doing was testing the coil assembly on my Zmax and setting the display to resistance at 3.0w with a batt in my Zmax that was at 3.5v.
I took the batt out of my Zmax, put it in my Vamo and retested at 3.0v, both coils. As mentioned earlier, the first coil came up as 'short' but the second one (did more wraps with 32g kanthal) came up to 2.6ohms on my Zmax and 2.5ohms on my Vamo.

I really wanted to get one of those carto ohm testers on a box but they were sold out everywhere.


As for the multimeter..operator/user error.
Any ideas/suggestions/admonishments/etc would be much appreciated

 

[E_DeCastro]

when it jumps around like that you don't have good contact. when testing something as small as an atomizer or cart you need three hands. ask someone to hold it for you and then test just as you were.

 

[BuzzKilla]

As E_decastro said... bad connection will make numbers jump around on you.... steady hands and some assistance will make things easier.

one thing worth noting. an ohm meter has its own resistance and that has to be factored in to get an accurate reading.
take your measurement, for the sake of an example say you get 2.0 ohms.
touch the two contacts of your meter together, and you will get a second reading... let's say 0.3 ohms....
your actual coil would be 1.7 ohms...

without a second pair of hands, i palm the atty/tank/carto, and with the same hand jam one of the probes to a contact(usually centerpost)
then with the free hand, i press the probe up against the threads of the connector.

dont get too frustrated, everyone starts somewhere; at least you did the right thing and got yourself an ohm meter

 

[tA71ana]

Thanks so much for your replies!
I will be getting the wicks for my RSST (my very first true rebuildable!) tomorrow, so I am determined to get this right, lol
Thanks so much for your guidance!
ECF rocks!

 

[newboy]

I got some spring-loaded clips to use with my meter. they clip onto the wires, so I get a more consistant connection. Also, I noticed you set your range to 200. If your meter has a lower range, that would give you better accuracy/resolution.

 

[E_DeCastro]

let us know if this helps if not we can see what else we can do to help.

 

[tA71ana]

Thanks so much
I tried to wrap up my RSST.
Initially I had one SS wick that was a little bit on the thin side so put two thin wicks next to each other and wrapped them together with 5 wraps of 32g kanthal. This is what I got...
I think I have the multimeter figured out but maybe you guys can determine if there is some type of anomaly or if any of you have encountered what I am experiencing.
The internal ohm reading I got when touching both leads together is 1.0
My MM reads 3.5 ohms when I tested the RSST. I subtracted the internal ohm reading which made the RSST 2.5 ohms.
I put the RSST on my Vamo (set at 3.0v on a 3.8v batt) and it initially read 2.5 ohms.
Then it went down to 1.9 ohms.
What in Sam Hill is going on here lol

 

[E_DeCastro]

I get that also and at first it was confusing me, but it's when the coils touch the mesh wick the resistance changes a bit. i was going from 2.5 to 2.9 then 3.5 this was while i was trying to get rid of hot spots. once I god rid of them it settled at 2.7

 

[BuzzKilla]

yeah, once you've settled on how many wraps of a specific gauge wire you like... the multi-meter is there just for verification...

I know its bad practice, but i only ohm out my coils after i know all my hotspots are gone. Just out of curiosity.

 

[E_DeCastro]

yeah, once you've settled on how many wraps of a specific gauge wire you like... the multi-meter is there just for verification...

I know its bad practice, but i only ohm out my coils after i know all my hotspots are gone. Just out of curiosity.

I agree, after a few times you will know x amount of turns should be about y ohms. the multimeter is just there to verify what you guessed.

I also recoil all my BCC so I have a little stock of those and I bag and label them , not that it makes much difference because I have a constant power out, when I get my ego, I want to use LR coils 1.25ohm or so. I want to know what I'm putting on what device. that and I'm an electronics technician so my Fluke Multimeter is my go to tool.

 

[Cavediver]

I bought one of these:
Prewired 510 Battery Connector, Sealed

Right now I'm using it with clip-style meter probes, but plan on cutting the clips off and soldering it together.

 

[E_DeCastro]

I bought one of these:
Prewired 510 Battery Connector, Sealed

Right now I'm using it with clip-style meter probes, but plan on cutting the clips off and soldering it together.

and put it in a box. or use bulkhead banana plugs and use banana patch lead that way you can still use your multimeter for other stuff.


I think i'm going to build one myself.

 

[tA71ana]

Well I re - wrapped it, lol
Now what I have is double skinny wick wrapped 5 times...I had it on my Zmax on a 3.8v batt and my voltage set to 3.7v.
I also screwed in the center post a tad bit more so that it poked out the bottom of the connector, but not so much that I might run the risk of loosening/displacing my center post on the Zmax.
I started to pulse and the resistence appears to stabilize at about 2.1 ohms but I notice that my mod is getting a bit warm..warmer than it would if I were using a carto of comparable resistance.
Heck, maybe I should have bought 34g kanthal... for a higher resistance coil with fewer wraps?
I am looking for resistance of between 2.0 - 2.5 ohms.
I'm gonna get this thing to work if I have to sit here and wrap/rewrap/pulse all day, lol

 

[E_DeCastro]

Well I re - wrapped it, lol
Now what I have is double skinny wick wrapped 5 times...I had it on my Zmax on a 3.8v batt and my voltage set to 3.7v.
I also screwed in the center post a tad bit more so that it poked out the bottom of the connector, but not so much that I might run the risk of loosening/displacing my center post on the Zmax.
I started to pulse and the resistence appears to stabilize at about 2.1 ohms but I notice that my mod is getting a bit warm..warmer than it would if I were using a carto of comparable resistance.
Heck, maybe I should have bought 34g kanthal... for a higher resistance coil with fewer wraps?
I am looking for resistance of between 2.0 - 2.5 ohms.
I'm gonna get this thing to work if I have to sit here and wrap/rewrap/pulse all day, lol

I did that went through three batteries from dry firing. lol.

 

[tA71ana]

I forgot to add that I am using a 18350....should I use a larger batt, like a 18500 or 18650?

 

[E_DeCastro]

should be fine with the 18350 the bigger batteries will just give you more capacity (longer times on battery less charging)

 

[tA71ana]

Sheesh..I looked so easy when Pbusardo did it, lol

 

[tA71ana]

should be fine with the 18350 the bigger batteries will just give you more capacity (longer times on battery less charging)

Kewl..the only batt that I have that is not fully charged is this one 18350...

 

[E_DeCastro]

I wrap perfect coils on screws. for more turns with tighter coils (micro coil) I use a .256 screw. for bigger coils for less turns I use a 4-40 screw. for my rba i used a drill bit the same size as the wick hole.

 

[BuzzKilla]

I forgot to add that I am using a 18350....should I use a larger batt, like a 18500 or 18650?

FOR GODS SAKE YES!
A hotspot with a measured resistance of 0.3 ohms can burst close to 13 amps through that little 18350....
Maximum continuous discharge rate is only 6 AMPS!
that's the main reason everything is getting hot... your pulling more current than that battery wants to!

get an 18650 mod to setup your coils... your batteries will thank you, and the fire department will thank you.

regardless of what your setup is, a short in the coil will always spike your amperage, play it safe and keep a high amp battery for setups. Keep your fingers crossed while you still have them.