Avocado Build Question

[Edna]

Hi all,

I bought an Avocado 3ml RDTA and I'm loving it. However I'm having trouble with the build. It keeps bouncing around on my mod. It read .19 ohms....Now after using it a couple of times it's suddenly reading .11 ohms on my meter. I took it off my mod (eleaf 60 watt TC) because the vape changed for a lack of better words. I Don't quite know how to describe... it but it was just dramatically different...So, instead of hurting myself or my new mod I just yanked it off until I could get some feedback.

Should I just take it apart and rebuild it? My tank didn't come with the single coil ceramic thingy though it should have... so I ordered one and it's on a slow boat from china (slowtech) I want to keep it around 2-3ohms because that's what I seem to like. My melo runs about 0.26 and that seems about right.

I built it with  (2)  28WAG, 0.2 ohm Nichrome, 9 wrap coils (I hope that's enough info) They're not shorting anywhere or popping or doing anything else weird. I'm using a Samsung INR 18650-25R battery with it. So if I figured right the battery is ok for the build. I'm at a loss as to why it happened.

When I first built it the flavor was amazing now ...not so much.

Suggestions from you build wizards please  

I'm enjoying building and this is my first RDTA  but it seems to combine the best of both worlds... flavor and tank...I still really like my Melo III and iJust 2 but I want to learn to build in case of things getting dicey with the new rules.

The good news is that I just found out that eleaf has come out with RBA build kits for the coils that the Melo and iJust 2 take and I ordered 5 of them so hopefully I can stop buying the pre-made at almost 9 bucks a pack (fasttech) also because my B&M wants $15 a pack and that's ridiculous especially since I like dark chocolate desert juices ...I go through a whole lot of coils.

Thanks all for the help!

[Bebop]

Just want to clarify

You want between .2 and .3, correct?

You are building a dualcoil, correct?

Are you using nichrome? Or Kanthal?

What diameter of coil? (spindle size)l

Are you testing the resistance of each coil before mounting?  Or measuring resistance after both are mounted?

[FXRich]

Sounds like you might have a loose screw, try tightening the screws, sometimes the heat can cause the screws to loosen. I'm not familiar with your particular tank so that's all I can offer.

Please disregard a loose screw will cause more resistance not less, looks like I might have had a loose screw for a few minutes. how close to the side of the tank are your coils, one may be shorting on the side of the tank.

Edited July 22, 2016 by FXRich

[Bebop]

No, you're right Rich.  Her .19 reading could be the high one.  Loose screw should always be looked in to. 

Her coils could be uneven. Who knows. Hard to say til we get details.

No, you're right Rich.  Her .19 reading could be the high one.  Loose screw should always be looked in to. 

Her coils could be uneven. Who knows. Hard to say til we get details.

BTW she should be targeting .5 ohm each coil. If her target was .2 ohm then it should read .1 (Yikes!!) I start getting nervous below .4 haha. 😣

Wait a sec.  9 wraps gives .2 ohms?  She must mean she's using nickel? 

It's not unusual to get fluctuations with nickel wire. Nickel moves around more with heat. 

[FXRich]

Personally I don't go below .5, sometimes I get .49 or .48 but that's expected. I have tried dual coils, but don't see a advantage to it, but that's just me.

Something doesn't sound right, 9 wraps of 28g nichrome80 around 2mm should give about 1 ohm per coil, with 2 coils she should get a total of .5 ohms. and that's on the low side since 3mm id is preferable.

[Edna]

8 hours ago, Bebop said:

Just want to clarify

You want between .2 and .3, correct?

You are building a dualcoil, correct?

Are you using nichrome? Or Kanthal?

What diameter of coil? (spindle size)l

Are you testing the resistance of each coil before mounting?  Or measuring resistance after both are mounted?

Hi All...Sorry went to sleep before I saw reply's Thanks for your help!

I was shooting for 0.3 I wanted single coil but since the ceramic thing-y didn't come I figured I had to build dual.

I'm using nichrome 28g

The diameter is about 0.3mm (how wide the coil itself is)

I measure once I had both coils mounted.

No screws were loose.

I tore up the build and am going to start over.... drat it

5 hours ago, FXRich said:

Personally I don't go below .5, sometimes I get .49 or .48 but that's expected. I have tried dual coils, but don't see a advantage to it, but that's just me.

Something doesn't sound right, 9 wraps of 28g nichrome80 around 2mm should give about 1 ohm per coil, with 2 coils she should get a total of .5 ohms. and that's on the low side since 3mm id is preferable.

That would work. I am ok with 0.5 ohm I just don't want to burn the bejesus out of my throat with heat I like it on the cooler side. I had a guy at the B&M build a coil for me and it hurt to vape it was so hot. ( I haven't been back to that B&M since they've given me lots of bad advice)

[Edna]

Here's a picture of the old coil and one of the new one I just built

[Tam]

You do good work, there, Edna. Very nice! 

[Edna]

Good Morning Tam,

I'm glad to see you got your computer problems fixed!    It's a bugger when they don't cooperate

Thanks, but I seem to be having trouble with getting the  darn things right I can make them look pretty but I can't seem to get the build quite right...well on this one anyway. I'm still trying to get the ohms thing figured out. I know what I like.... it's just trying to figure out how to get there...

Thank goodness for you all here giving me a hand with it.

[Bebop]

The coil looks good.  But if you build 2 coils it's going to ohm out at about .14.  That is one hot coil.  (Or two,. Haha)

 

[FXRich]

You did a good job of making that coil, but one thing does bother me about it, I see 6 wraps, 6wraps of 28g Nichrome around 3mm should give you about 1.0 ohms not .28 ohms, which is what you should get using 22g Nichrome, you may have gotten a roll of wire that was mislabeled.

[FXRich]

The only way you could get .28 ohms out of that coil built with 28g is if the coils are fused together.

[Bebop]

 You might be on to something, Rich. The picture is not clear but that wire could be heavier than 28g.  

[Edna]

6 hours ago, FXRich said:

You did a good job of making that coil, but one thing does bother me about it, I see 6 wraps, 6wraps of 28g Nichrome around 3mm should give you about 1.0 ohms not .28 ohms, which is what you should get using 22g Nichrome, you may have gotten a roll of wire that was mislabeled.

@FXRich @Bebop

Sorry was running around today and haven't been able to get back online...yes, that's 22g stainless actually I had that one figure out for my Bellus RBA so I went with what I know and I only did a single build and just closed up some of the air holes ...

I really like the Avocado and wanted to take it with me so I cheated a bit

5 hours ago, Bebop said:

 You might be on to something, Rich. The picture is not clear but that wire could be heavier than 28g.  

Good eye....It's 28g Nichrome... you're right I cheated and switched wires sorry I should have noted it

Edited July 22, 2016 by Edna

[FXRich]

Eventually you will figure out the best build for you, we all have gone through a learning curve.

[Edna]

Thanks for the moral support   I'm just careful since it's new. I found an ohm coil calculator online and hopefully it'll help me get it right. It shows what the build should be. Also, I found another that is what the battery can handle. I think it'll be an asset as I'm learning. It's pretty straight forward

Here's a link  https://www.misthub.com/blogs/vape-tutorials/76788933-tutorial-ohms-law-and-vape-safety-calculator

Edited July 23, 2016 by Edna
typo

[jasonculp]

1 hour ago, Edna said:

Thanks for the moral support   I'm just careful since it's new. I found an ohm coil calculator online and hopefully it'll help me get it right. It shows what the build should be. Also, I found another that is what the battery can handle. I think it'll be an asset as I'm learning. It's pretty straight forward

Here's a link  https://www.misthub.com/blogs/vape-tutorials/76788933-tutorial-ohms-law-and-vape-safety-calculator

Edna,

That is a handy calculator, but it doesn't use the correct calculations for a Variable Wattage or Temp Control mod.  Ohm's law must be calculated for both sides of the chip inside your mod. (The calculator works fine for a mechanical mod)

The simplest way to figure it is:  Wattage / Low battery cut off voltage * 1.1 (add 10% for the inefficiency of the board) = Total Amp Draw

So if you have a mod (with any ohm coil that it will fire with) and it is set to 60 watts and has a single battery it will pull 18.86 amps because:

60/3.5*1.1=18.87 

Most mods cut off around 3.5 Volts.  With a board inside them amplifying the voltage to you atomizer the lower your batteries voltage, the more demand it is asking from the battery.  On the example above, the board it having to amplify the batteries 4.2 Volts (at full charge) to 5.4 Volts at the atomizer to deliver 60 watts.  This requires 15.71 Amps to boost the voltage when the battery is fully charged.  When your battery is low (3.5 V) it requires 18.86 Amps.

Here is a link to the handiest calculator on the web, but it can be a bit complicated:

Steam Engine - Coil Wrapping

Steam Engine - Battery Draw - to use this make sure to check the "regulated" check box and "power regulation" check box.

I always recommend for beginners to use a pretty good Variable Wattage mod for building.  It is just another level of safety.  If the mod senses it is shorted, it won't fire, and if the battery gets too low it won't fire.  You can still over tax the battery inside it, but it is much harder to do.

Have fun with it, building your own coils can be very satisfying.  It not only lets you tailor the coil to your vape, but it is also much less expensive once you have your tools/supplies.  I rewick my coils every 3 days or so.  This gives me a "new coil" vape for pennies.

[Edna]

@jasonculp

Thanks for the link! I bookmarked it.  It doesn't look too terribly confusing once I play with it for awhile to get the hang of it.

I usually  put my built deck on my istick 40 to see what it is reading, and for the numbers to plug into the calculator and to check the ohm meter. That way I get the numbers before I fire it on my mechanical mod to burn off everything. Then I re-check it again on both after.This is before I get it anywhere near my face. I try to triple check myself. No accidents for me.. If something isn't right I stop.

I don't use my SMPL mech mod for anything other than builds really though I have tried a tugboat RDA on one once, it wasn't something I felt too safe with ...

I use my eleaf 60W, Pico and Istick 40W mainly and occasionally my dripbox so they are all regulated.

I'm Still a noobie and trying to be  careful one

Thanks for your help and patience !

 

[FXRich]

Why nobody has mentioned steam engine to you before now is a mystery, I use it all the time, mostly I use the wire wizard section, but have used the other parts also. Maybe someday they will make a downloadable version where you won't have to get on the net.

[Edna]

22 hours ago, FXRich said:

Why nobody has mentioned steam engine to you before now is a mystery, I use it all the time, mostly I use the wire wizard section, but have used the other parts also. Maybe someday they will make a downloadable version where you won't have to get on the net.

That or a phone app. I've been playing with hypothetical builds so I can get the hang of it. It's a great resource to have now that I'm understanding it more.