pro tank coil build problem

[intrepid31]

Ok so I'm new to coil building and I'm trying to build a coil for my kangertech protank 2, kamry k1000 e-pipe tank, and my wife e-cig tank all of which are 2.4 ohm coils. I have talk to my local shops and they have all been very helpful, but no one seems to have an answer for my problem; so here my issue.

I can get the coil made and test it without any wick in it or it the coil actually being put into the stem. When I test the coil with my multimeter I can get my 2.4 ohm (2.2 to 2.5) reading. Then I put the coil into the stem (without a wick), trim the extra wire off and retest the coil and the reading keep coming up at 1.6 to 1.9 ohms on my coil tester and my multimeter. I have added wraps, subtracted wraps, made triple sure that the coil is not touching the stem wall, I have heated the coil while holding it compressed with needle nose, and I have not used heat on the coil. I have tried 28,30,32 g wire. I have tried a 1/16" drill bit and 1.02mm bit (which is the same size as a 18g blunt tip needle) All of this have ended with the same result 1.6 to 1.9 ohm reading.

Here is I'm using:
Kanthal A1 28,30, and 32g wire
1/16", 1.02mm drill bit
butane torch
cotton wick

Can someone please tell me what I am doing wrong.

 

[alexmot]

What is the problem? Are you aiming for 2.4 ohm coils and getting 1.6 - 1.9?

At least the protank 2 single coils can go up to a 2.0mm inner diameter coil.

Check out the coil wrapping calculator at www.steam-engine.org.

You should be able to get ~2.5 ohms by doing 9 wraps of 32g kanthal around that 1/16th " drill bit and mounting it in a protank single coil head.

 

[edyle]

check the coil ohms before you add the top chimney spire thing on top the head.
When you add the top spire, it is probably touching the coil causing a partial short.

Nowadays it's much better because you can get the subtank mini which comes with a coil head made for rebuilding.

 

[intrepid31]

What is the problem? Are you aiming for 2.4 ohm coils and getting 1.6 - 1.9?

At least the protank 2 single coils can go up to a 2.0mm inner diameter coil.

Check out the coil wrapping calculator at www.steam-engine.org.

You should be able to get ~2.5 ohms by doing 9 wraps of 32g kanthal around that 1/16th " drill bit and mounting it in a protank single coil head.

Correct I am aiming for 2.4 ohm and getting it when I check the coil with a multimeter when the coil is out of the stem/chimney as shown in the pic.

But when I retest the coil once it has been placed into the stem/chimney and the extra wire has been trimmed I get 1.6 -1.9 ohm reading (as shown in this pic)

 

[intrepid31]

check the coil ohms before you add the top chimney spire thing on top the head.
When you add the top spire, it is probably touching the coil causing a partial short.

Nowadays it's much better because you can get the subtank mini which comes with a coil head made for rebuilding.

I have been making sure that the coil is not touch the stem/chimney walls. Unfortunately my walls don't come off like you have shown as you can see form my last post.

 

[edyle]

Correct I am aiming for 2.4 ohm and getting it when I check the coil with a multimeter when the coil is out of the stem/chimney as shown in the pic.

But when I retest the coil once it has been placed into the stem/chimney and the extra wire has been trimmed I get 1.6 -1.9 ohm reading (as shown in this pic)

well yes when you trim off the extra leg length you lose the resistance of that extra leg length, you have to account for that extra leg length when taking your measurement.

Also you have to account for the zero offset of your multimeter.

Just add a couple extra wraps.

 

[pandasku]

still using protank, hard work, time to move on, dude.

 

[intrepid31]

thanks to edyle and alexmot your tips helped me get it figured.

 

[wheelie]

I have rebuild hundreds of them. Are you sure both coils are firing. I put my two coils on tattoo gun needle bars. Drop the first coil down and then a opened up paper clip and wind the lead around both bars. Then I drop down the second coil. What the paper clip does is creates a space between the two coils. Most times erratic readings are one of the leads are grounding out. Hardest part of the rebuild is clipping the wires when done the rebuild. Sometimes it takes me 1/2 hour to find the stubborn wire causing the problem. When it happens I always wait till daylight and look for the wire in front of the window when the sun is shining. Good luck to you. CHEERS!