Need help! my kanthal gives too much resistance

[LycanFury]

Hi,

I am trying to rebuild the coil for my vivi novas, also tried for a genesis style. The issue i am having is with the wrs in the coil. To give a bit of background on the material i am using, i got Kanthal 32 awg from a vendor site called heaven-gift .com. i works fine but if i give 4-5 wraps i get 3 -3.5 ohms on my vamo also confirmed this via.. my multimeter. When I reduce the wraps to 2 I get 2.5 ohms.

I feel this is quit strange, because as per the videos of coils wrappings be for vivi novas or the genis, by rip trippers pbausardo, junkyrock.
3-5 wraps should provide around 1.8 to 2.5 ohms.

Am i missing something, please advice.

Thanks
LF

 

[asdaq]

Have you measured the Ohms for the kanthal with your DMM just by length? Then you can determine what length you need for a coil and add a bit for the connections. Then just wrap the coil with this, install and see how close it comes.

 

[LycanFury]

By connections you mean attach the resistant wire to the non-resistant one?

 

[Berylanna]

I'm having similar issues with 33, but I've been able to get them down to 2.8 by doubling and twisting the part of the wire that goes from the coil and down the tube, so that cuts the resistance of that in half, roughly. I'm going to try a 4/3 wrap next, and also try using a thinner needle, and check to make sure my cheesecloth is really 30 threads instead of 35.

 

[asdaq]

By connections you mean attach the resistant wire to the non-resistant one?

Any part that won't be counted in the coil because of any screws, pins or NR wire, what have you. For both of you, the diameters of your wicks might be different than what you are going on for reference, I dunno.

 

[DaFreeK]

Hi,

I am trying to rebuild the coil for my vivi novas, also tried for a genesis style. The issue i am having is with the wrs in the coil. To give a bit of background on the material i am using, i got Kanthal 32 awg from a vendor site called heaven-gift .com. i works fine but if i give 4-5 wraps i get 3 -3.5 ohms on my vamo also confirmed this via.. my multimeter. When I reduce the wraps to 2 I get 2.5 ohms.

I feel this is quit strange, because as per the videos of coils wrappings be for vivi novas or the genis, by rip trippers pbausardo, junkyrock.
3-5 wraps should provide around 1.8 to 2.5 ohms.

Am i missing something, please advice.

Thanks
LF

As far as I know heaven-gifts sells only 0.15mm kanthal. Don't know what AWG that is, but 32AWG is 0.20mm. So their kanthal has much more resistance per inch then 32AWG.


Sent from my Nokia 3310 using Tapatalk

 

[slimest]

Kanthal 0.16mm about 40mm length has resistance 2.5 ohm. One wrap on a wick 2mm diameter is approx 7mm length. So for such a wick you need minimum 4-5 wraps even considering free ends.

 

[Tai Pan]

Kanthal D from Sweden has the following resistance per meter:

0,15 mm = 70,7 Ohm ± 5%
0,16 mm = 67,15 Ohm ± 5%
0,20 mm = 42,97 Ohm ± 5%

Chinese material sold by Heaven Gift is similar.

Uwe

 

[LycanFury]

Kanthal 0.16mm about 40mm length has resistance 2.5 ohm. One wrap on a wick 2mm diameter is approx 7mm length. So for such a wick you need minimum 4-5 wraps even considering free ends.

I don't know the dia mm I checked on the DMM for 40mm length that is 4cm in length its 3.8 ohms, shorter length would not be sufficient to go through the tube of the vivinova base.

 

[slimest]

LycanFury, 3.8 Ohm for 4 cm wire means that it is either:
- very small diameter (about 0.1-0.12mm or 36-38GA)
- this is not kanthal (nichrome maybe, it has more resistance)
- your multimeter measures wrong. Good practice - short multimeter's leads before measurements and remember given resistance (usually 0.2-0.5-0.7 Ohm, depends on leads and connectors quality). Then, when you measure resistance of your wire, just subtract this value from multimeter result. High quality multimeters have the special feature to automatically correct leads resistance. Also better results are if you reliably connect wire to MM leads.

Hope, my explanation on poor English is clear enough

 

[supertrunker]

i think the trick is to use silver wire on the legs of the coil that do go thru the Nova. that way only your heating part of the coil counts and anything below that point does not. I made a 2.3 Ohm one yesterday with 4 wraps of 32 AWG A-1 kanthal. I think that's better since the more wraps you use - the harder it is to fit it into that slot without shorting.

The way i do it is similar to that suggested above - i cut some kanthal and put a bend in it an inch from one end. Then i attach one lead from my multimeter to it and some silver wire. Next i move the free lead to a point on the wire until i hit the resistance i want and bend that too. That is the bit in the middle that gets wrapped.

T

 

[slimest]

Sorry, my statement about nichrome is wrong. Nichrome has less resistance. So you can consider only diameter and multimeter problem...

 

[tencars]

This chart helped me pick the size of Kanthal I use for my Vivi Novas. I use the 28awg is a bit easier
to work with for me and has less resistance for the small distance(s) we use. Mine are coming in at
1.8ohm with 4/5 wrap.

Kanthal A-1

Gauge Diameter Ohms/ft. @ room temp
16 0.0508 in. (1.29032 mm) 0.324
26 0.0159 in. (0.40386 mm) 3.31
27 0.0142 in. (0.36068 mm) 4.15
28 0.0126 in. (0.32004 mm) 5.27
29 0.0113 in. (0.28702 mm) 6.55
30 0.0100 in. (0.25400 mm) 8.36
32 0.0080 in. (0.20320 mm) 13.1
33 0.0071 in. (0.18034 mm) 16.6
34 0.0063 in. (0.16002 mm) 21.1
36 0.0050 in. (0.12700 mm) 33.4

Kanthal D
Gauge Diameter Ohms/ft. @ room temp
26 0.0159 in. (0.40386 mm) 3.21
36 0.0050 in. (0.12700 mm) 32.5

Resistance
------------------
The more wire you have, the greater the resistance.

The factors that affect resistance are:

Diameter: The thinner the wire (higher gauge number),
the higher the resistance per foot.
The thicker the wire (lower gauge number),
the lower the resistance.

Length: The longer the wire, the higher the overall resistance.
The shorter the wire, the lower the overall resistance.

Temperature: The more heat the wire generates,
the more resistance it will create.

 

[LycanFury]

Hi Slimest,

Thanks for the idea i checked the dia for the wire its 0.1219 mm, that makes it around 35-36 awg. that explains alot.

lower gauze=higher ohms