Steam Engine Never Agrees

[ShowerHead]

I have been DIY for some time now and have a question.
When I enter a coil on steam engine, I always get an unreasonable amount of wraps to achieve the desired resistance.
For example, I have SS430, 28ga, 3mm ID spaced wraps on a machine screw. Going to go into an Aromamizer Supreme. I built this using 6/5 wraps. Each coil comes out at .74 which give me .37 on both the 521 I build it on and on the dna 200 mod I vape it on.
Steam engine says it should be 9/8 wraps.
First, I don't know if that many wraps would fit on the deck. Second, I have the coils built and vaping just fine, so I'm guessing my calculation is correct.
My reason for asking is that I am going to test a mech mod. I absolutely want >1 ohm and while I can test after building, I'd like to use steam engine to know how many wraps I will need to be in the ballpark.
Currently, I must not understand something about the site as I have way different results.

 

[Taowulf]

Are you positive the machine screw is 3mm? Like "measured with calipers" sure?

 

[AzPlumber]

Did you check the actual resistance of your wire per (mm, in or ft)?

 

[Taowulf]

I did some playing around with the ID, and according to Steam engine, the ID to get those numbers would be about 5.2mm. Even playing with the coil spacing between the default .01mm up to 2mm doesn't effect it that much.

 

[ShowerHead]

That is why I asked. Now, SS430 is springy and does 'uncoil' some once you release tension. Does it become 5.2? I shall endeavor to find out tomorrow when I wrap again.

I'll also take exactly a foot of this wire and see if I can get a measurement of its resistance with my trusty Radio Shack multimeter. If not, I can attach it to a base and see what it reads.

 

[Taowulf]

That is why I asked. Now, SS430 is springy and does 'uncoil' some once you release tension. Does it become 5.2? I shall endeavor to find out tomorrow when I wrap again.

There ya go. That is probably a big reason why.

When you mount the coil, do you leave it on the machine screw until you have your leads secured? I used to do that with Ni200 when I did TC

 

[AzPlumber]

I'll also take exactly a foot of this wire and see if I can get a measurement of its resistance with my trusty Radio Shack multimeter. If not, I can attach it to a base and see what it reads.

Keep in mind that a multi-meter can have inherent resistance in the leads and probes. Touch the probes together and note the reading, this must be subtracted from any measurement taken.

 

[ShowerHead]

There ya go. That is probably a big reason why.
When you mount the coil, do you leave it on the machine screw until you have your leads secured? I used to do that with Ni200 when I did TC

I leave it on the screw, but when I take it out, it does expand a bit.
I'll measure when I take it off tomorrow.

 

[ShowerHead]

Keep in mind that a multi-meter can have inherent resistance in the leads and probes. Touch the probes together and note the reading, this must be subtracted from any measurement taken.

Yep, I'll make sure to only measure the wire.

 

[ShowerHead]

I used a slightly different method until I can get out and get some good alligator clip leads.
I cut a piece of 28ga Kanthal and a piece of the SS430.
Called my wife into the room and asked her which is bigger?
She looked at each end-on and felt them then said this one is smaller. It was the SS430.
Since it was a very small difference, I put 29ga into Steam-Engine. Presto! I get the same values as my 521 and mods show for the coils.

Not scientific and I will measure the wire, but for now, looks like the 28ga may be 29ga.

 

[Saintskinny51792]

Mystery solved! Nice work gang! The SS403 would've gotten away with it too if it weren't for you meddling kids and your Scooby Snack E-juice!!!

I used a slightly different method until I can get out and get some good alligator clip leads.
I cut a piece of 28ga Kanthal and a piece of the SS430.
Called my wife into the room and asked her which is bigger?
She looked at each end-on and felt them then said this one is smaller. It was the SS430.
Since it was a very small difference, I put 29ga into Steam-Engine. Presto! I get the same values as my 521 and mods show for the coils.

Not scientific and I will measure the wire, but for now, looks like the 28ga may be 29ga.

 

[AzPlumber]

I used a slightly different method until I can get out and get some good alligator clip leads.
I cut a piece of 28ga Kanthal and a piece of the SS430.
Called my wife into the room and asked her which is bigger?
She looked at each end-on and felt them then said this one is smaller. It was the SS430.
Since it was a very small difference, I put 29ga into Steam-Engine. Presto! I get the same values as my 521 and mods show for the coils.

Not scientific and I will measure the wire, but for now, looks like the 28ga may be 29ga.

Instead of getting aligator clips you could use a simple jig to measure resistance of a fixed length of wire. A board with holes spaced 12" apart for the probes and wrap the wire around each probe.