Need advice on current A7 rebuild

[planes]

Hey all. Just got a couple rebuild-able atomizers in and built a coil on one of them. The A7. The coil came in at 1.5 ohms.
I'm getting some good vape but the flavor and TH are lacking. I'm thinking I used too much cotton.



If I decide to go two coils, I'm not sure of the formula. Would 2 1.5 ohms make .75 ohms? And is that because one power source is divided into two. Am I wrong on this? If that's right, then to keep from going sub ohm, I would need at least two 2 ohm coils and two 3 ohm coils would make 1.5 ohms?

 

[emus]

Your math is ok. 3+3=1.5.
I'm guessing your air flow isn't right.
Coil should be directly in air flow path.
Wick shouldn't obstruct air flow path.
pics not clear from here.

 

[planes]

Thanks. You mean in direct airflow from the air hole? And then should cotton not be through coil?

 

[Richard75]

Thanks. You mean in direct airflow from the air hole? And then should cotton not be through coil?

No, keep the cotton through the coil. Poor airflow usually results in too much throat hit, so I doubt it's that. When you tested the coil, did it light up nice and evenly? Also, what device are you using it on?

I'd say try a microcoil out. It doesn't look like one from your pictures, but they've always provided a nice, consistent vape for me.

If you decide to make dual coils, make sure both coils are exactly the same. Also make sure both get proper airflow... the A7 has airflow from the bottom, so it may be a bit trickier than side airflow.

 

[emus]

Many configurations work.
I mostly use cotton wicks packed kinda firm inside coil; perfecting wick packing firmness may take some experimentation.
Too tight results in choked dry wick.
Too loose results in low vapor production.
Air follows path of least resistance.
I have good results when coil is close to air hole.
If air flow doesn't wrap around coil then low quality vapor may result on some builds.

Is your coil directly above air hole?
Is your wick very loose inside coil?
Voltage drop around 0.3 volts is ok.
can you measure voltage at coil?

 

[planes]

I'll do more configuring tomorrow and report back. I did notice on my coil rebuilds on PT 2 minis that when the cotton wick sat over night it got much better so maybe the cotton needs to pickle a little. I'm just throwing things up in the air. Tomorrow I'll test the points made by richard75 and emus. BTW how many wraps on a 5/64 makes a micro coil. I've got 30 and 32 gauge. I know 12 with 28g is micro. I'll report back.

EDit Sorry 12 is nano. Micro?

 

[emus]

For my A7 clone I like:
3/32" ID.
Twisted 30GA kanthal; 2 strands twisted on drill seems to stay wet better than single strand.
8 wraps roughly 1.4 ohms is my A7 clone sweet spot.
Micro coil style.
I do like umbrella wick above coil to keep air hole nice and dry; air path clear under coil.

 

[planes]

Thanks to emus I was able to make a nice coil. Twisted 30 gauge 8 wraps. Getting a nice vape and th but I'm still working on flavor. It's good but not where I want it.

Strange though and maybe someone can chime in. I'm getting .8 ohm reading on the MVP2 and it's vaping this coil wick setup. MVP's aren't suppose to vape sub ohm right ?

 

[planes]

 

[emus]

0.8 is pretty low but should produce flavor if your PV can handle the amperage draw.
I like 0.9 but usually target around 1.4 to promote batt life.
Did you experiment with different voltages/watts?
Did you try packing cotton wick semi-firm into coil with a blunt tool like a drill bit?
Did you try to lower coil closer to air hole?
It is nice to run same juice in two RBAs for comparison; it is common for vaper's taste buds to sleep for days at a time.

 

[planes]

Yes to volts/watts. I'll try to pack the cotton tighter.(This could be the issue.) Yes, I got coil closer but maybe I can try closer. I have a dual coil IGO T I can set-up. My taste could be hurting some but I don't vape all day. Just for about 3 hours total in afternoon and after dinner.

I'll do some tweaking tomorrow. Still can't figure how the MVP 2 is running sub ohms. It's supposed to error below 1 ohm?

 

[emus]

Yes to volts/watts. I'll try to pack the cotton tighter.(This could be the issue.) Yes, I got coil closer but maybe I can try closer. I have a dual coil IGO T I can set-up. My taste could be hurting some but I don't vape all day. Just for about 3 hours total in afternoon and after dinner.

I'll do some tweaking tomorrow. Still can't figure how the MVP 2 is running sub ohms. It's supposed to error below 1 ohm?

Your ID must be tighter than mine to get 0.8 at 8 wraps. I've had wicking issues through smaller coils.

Maybe visit rip trippers on YT since he is a flavor junky.

 

[planes]

Yea! I might go wider to get the ohms up and push more cotton through. I actually don't really need sub ohms since my device goes up to 5 volts. I've seen several of trippers videos and I think he does about the best on youtube. I like him for instruction and grimm for reviews. I think I'll go to 5/64 and 8 wraps. Maybe 9 if I can buy a torch to set it. Thanks. Out for the night.

 

[mackman]

For my A7 clone I like:
3/32" ID.
Twisted 30GA kanthal; 2 strands twisted on drill seems to stay wet better than single strand.
8 wraps roughly 1.4 ohms is my A7 clone sweet spot.
Micro coil style.
I do like umbrella wick above coil to keep air hole nice and dry; air path clear under coil.

IMO you got way too much cotton in there for the A7. For the TH raise the coil off the deck directly in front of the air hole and as forward to the air hole as possible without shorting on the cap.

 

[emus]

IMO you got way too much cotton in there for the A7. For the TH raise the coil off the deck directly in front of the air hole and as forward to the air hole as possible without shorting on the cap.

That is one junky A7 clone. I was disappointed when it produced better flavor than my other RBAs. Before the cotton umbrella it would leak through bottom air hole when drip through DT.

How do others avoid leakage when dripping on bottom air feed RDA?

 

[planes]

So far I'm not very impressed with the A7. I'm getting superior performance from my pt minis and Kanger tank with rebuilt coils and cotton wick. The flavor TH and vape cloud are superior. I'm gonna try a 2.4 ohm coil on the A7 today and see if it performs better with the MVP 2. Other than that, It's gonna get drilled out into a dual coil RD and abused.

 

[emus]

This cousin of the A7 is my vapor quality gold standard.
Side air hole instead of bottom air feed.
1.2ohm twisted 30GA at 3.7v.
Very smooth TH.
My small diameter RBAs tend to produce higher quality vapor.

 

[JmanEspresso]

The full size A7 was my first RDA.

Once you get the hang of it, its a good little atty. Definitely teaches you how to work in tight spaces thats for sure.

Heres how I did it once I got the hang of it...


Pack the whole cup with wick, so that there is no pooling of liquid.

Put the coil as close as you can to the air feed tube, without it actually touching the air feed tube

Dont overdrip


At times, the A7 can seem like a broken design, but once you get it working, it can produce some great flavor. If it was for the A7, I wouldn't vape like I do. The A7 opened the door to RBAs, and mechs. Now, I dont vape on anything but rebuildables on top of mechs.

 

[planes]

This cousin of the A7 is my vapor quality gold standard.
Side air hole instead of bottom air feed.
1.2ohm twisted 30GA at 3.7v.
Very smooth TH.
My small diameter RBAs tend to produce higher quality vapor.

That's pretty funny but ingenious.

 

[emus]

That's pretty funny but ingenious.

My green Altoids mod was my daily mod for 2 years.
That thing is beat to heck but still works.
Has industrial feather touch switch; pleasure to use.
Stored juice and carto inside and kept in pocket.
I had to hammer out dents a few times.
Switched to tubes and RBAs when my CE2 became obsolete.

The red one was my backup w/ low miles.