I built a 28g coil, 9 wraps with a 1.8 id. According to vapors tool box it should have been 1.5ohms but it's reading at 1.3 on my multimeter and sigelei. What could have caused the .2ohm difference? Did I not leave the legs long enough?
im a bit confused
- Thread starter solipsistic xerophyte
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I ran the numbers on http://www.steam-engine.org/coil.asp?r=1.2&awg=28&id=1.8 and got 1.2 ohms for that build with a 5mm leg. To get 1.5 ohms the legs would have to be 22mm long, so not that. Maybe what you are wrapping around is not 1.8 mm? I'm not familiar with that calculator, maybe it's wrong.
The calculator seems fine to me. I was using it to rebuild my protank 2 coils and I always hit the resistance I was aiming for. I may have mixed up my screwdrivers in my set so that may be the problem. I'll go and check to see if they are in the right order. It wouldn't be the first time I placed them in the wrong position.
Just checked steam engine and According to it I was one wrap off. It says I need 10 wraps instead of nine. So I guess the vapors toolbox app isn't 100% reliable.
I would suggest that NO calculator is 100% accurate........ Too much variability in materials and Build for 100%. Wind Tension alone could account for the .2ohm difference, not to mention wire variability..
Yes I'm slowly learning that 93gc40. This is why I always check my coils and batteries before placing them on my device. But I think I may need to pick up one more multimeter so I can have two checks on my coils instead of one external and one on my device.
I didn't even consider that. I tried keeping my wraps as close as possible but ended up with some slight eve. Spacing between them.
I've always understood it as the length of the wire being the factor in resistance of the coil for a given gauge, so the number of wraps and leg length are determined by inner diameter and wrap spacing....
Coil spacing has ZERO affect on the OHMs of a coil.OHMs is a result of wire diameter and length, doesn't matter how you coil it or if you wad it into a ball. 3" of a given gauge kanthal will always read at the same ohm.
Spacing affects how the heat of the coil is distributed. It does not affect the ELECTRICITY part of the equation.
That's not what I was implying.... The more space between coils, the slightly more wire is used per wrap, increasing the ohms ever so slightly if you're only doing your coils on the number of wraps....
So it turns out I was one coil short. Just built a ten wrap coil with the same gauge wire and id and it came out to 1.5. Glad it turned out to be a simple fix.
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