Coil & MVP Ohmmeter Question

[Twicehorn]

Built my first coil with 28ga Kanthal a while back for use in Russian 91 on an MVP2. Used 5 wraps on a screwdriver and it came out 1.1 ohm. Oops. Kind of. When I first put it on, I got some 0.7 and 0.8 readings. But it leveled off at 1.1.

So after a couple of weeks, I decided to install another one I made with 8 turns this time. Got it screwed on, fired it up. Ohm'ed it. 4.3. OOOPS. .... So, I pinched it together, made sure it was off the deck (looked like there might have been some debris between one leg and the deck). Burned it again, pinched. Got 2.3 or something. Well. Ok. Wicked it with cotton, juiced it up. Now I'm getting a steady 1.4. Nope, check it, just got 2.2.

Vapes just fine and stays a bit cooler than the 1.1. I upped the wattage to 7.5 from 6.0. Working fine, but I'm getting some odd and suboptimal resistance readings.

Any theories?

 

[CastleRat]

I'm sure you checked for touching windings, check and clean all contacts including those on you meter. At lower voltages even a speck of dirt, grease or wax can cause problems. I usually clean with isopropyl alcohol, rinse with water. Oh, don't forget your coil leads

 

[Twicehorn]

What about coil leads? It's a clone so it has the tiny screws and with the fat kanthal I wrapped around pretty much a full turn. The ends are nipped off pretty close (I would have to file them to get closer) but the chimney is tight so I could see some contact there. I cleaned with water pretty thoroughly before building, but didn't bother with alcohol.

And the windings are touching because they weren't when I started and got the 4.3. So I pinched it up (it is or was pretty long) after burning and now its a "microcoil" I guess.

Nothing really to worry about I guess, it is working just fine. Just curious about the behavior.

 

[PorkchopReg]

I think when you build your first few coils, consider them to be useless...
There are great videos out there on youtube, but until your 5th try, you readings will be all over the place.

What resistance level you trying to obtain?

 

[Weizenheimer]

Is this an R91 v2 with the floating pin? If so they are known to have an issue with fluctuating resistance.

 

[TomGeorge]

How old is your MVP? I just mine for 2 months or so wit hjust the iclear30 that it came with. then I got an igo w and started using that. i has similar reading fo-pas with mine as well. I eventually figured out that I had been tightening down the iclears to tight and pushed the center contact on the MVP down to far. this caused poor conductivity and poor reading.

Also, my dad has/had an mvp that he would take to work with him (construction) so it got filthy and often times that would be the issue.

Lastly, my dad and I both dropped our mvp's from time to time and that generally made the ohm meter worse and worse.

 

[Twicehorn]

Not sure if it is a v2. It is a more recent addition to ft, sku 1612101. Haven't messed with the pin. With the old coil it was all over at first, from the "dangerous" subohm to 1.2. Finally completely stabilized at 1.1.

I was hoping for something in the mid to upper 1 ohm.


The mvp is a couple of months old. I haven't really dropped it, it has fallen from the coffee table to the carpet a couple of times. I use it in passthrough most of the time and I did have a wonky USB cable (contact no contact for a while).

But the erratic readings were a thing of the past until this new coil. It does seem to be stabilizing around 1.7, which is about what I wanted.

 

[realsis]

Sometimes when a reading is jumpire around it can indicate a short. If I get a coil which jumps around on readings, I remake another coil to insure a steady reading. I check it on both with my ohm meter then check again with my device. I won't use a coil that has a great fluctuations, you want a steady reading. Hope this heps.

 

[herb]

Sounds like your doing things right, i lightly compact my coils after they glow orange with light pressure from needle nose pliers and then continue to heat them to a glow until i get a steady reading . Anywhere from 1.1 on a Kayfun to 2.0 or slightly higher on Pro Tank style tanks and it works great .

Keep the legs short and make sure the chimney screws on easy without making contact from the leftover clipped legs as a chimney thats more difficult to screw down usually indicates the clipped legs are making contact with the chimney sides.

As far as how hard to screw down different tanks etc... i would say just snug and no tighter , i have used a rubber o ring (size 60) to slip over the top of the MVP's pins lip which prevents the pin from being pushed too far down .

If you happen to screw a topper on too tight the o ring will nudge the pin back where it should be after you take the topper off , it has worked flawlessly for me on two MVP's and is absolute cake to install.

To accomplish this , pull up your MVP's pin until you see the lip and stretch a 60 size ring over that lip and your done, it will fit perfectly underneath and you will never have an issue with pin contact again.

This eliminates the need for adapters and circuit board spacers.

 

[Twicehorn]

Sounds like your doing things right, i lightly compact my coils after they glow orange with light pressure from needle nose pliers and then continue to heat them to a glow until i get a steady reading . Anywhere from 1.1 on a Kayfun to 2.0 or slightly higher on Pro Tank style tanks and it works great .

Keep the legs short and make sure the chimney screws on easy without making contact from the leftover clipped legs as a chimney thats more difficult to screw down usually indicates the clipped legs are making contact with the chimney sides which will always cause fluctuating readings .

Chimney threads right on, but when I put it on to engage the threads, I can feel it hitting the stubs. Dont think that's a problem. It is stabilizing now.

 

[herb]

Chimney threads right on, but when I put it on to engage the threads, I can feel it hitting the stubs. Dont think that's a problem. It is stabilizing now.

Noted, i just screwed on a Iclear 30 replacement head that was supposed to be a 2.0 ohm replacement , shockingly it read 2.9 for the first couple seconds then 2.8, 2.6 and now it's at 2.1 and vaping great , rarely have experienced this but all is good now , hope your does the same.

 

[Jubs]

I run an Igo-W 90% of the time on my MVP V2 and the only time I have noticed ohm jumps is when I didn't have the coils tightened enough. I have noticed when I go to wick it and or adjust the coil position it will come loose a bit and I have to find a happy medium on the tension of the screws on the atty.

 

[Twicehorn]

As a follow up, yesterday it was mostly reading around 1.5, which is what I wanted. But this morning I hit it and got 2. something. Grrr. So I decided a wick change was in order and filed down the wire ends so there was less chance of contact with the chimney. So far, back to 1.5.