How much tension does a tension coil need?

[Setanta]

Hi folks,

Has anyone actually figured out how much tension you need to apply to make a successful tension coil? I've seen the figure of 7lbs in one thread but I don't know how that value was arrived at. That said, looking at optimal tension for winding copper wire and comparing that to kanthal it seems (to my VERY limited engineering knowledge) to be in the ballpark.

I realise that the exact amount will change depending on that gauge of the kanthal used, and to a lesser extent the particular kind of kanthal used and I'm guessing that nickel/nichrome/titanium builds will require less tension than kanthal, so what I'm really looking for is a ballpark figure for the sort of gauges typically used in making coils.

Just while I'm here - a couple of other questions for those that might know this sort of thing…

For the tension coil gurus…

Am I correct in thinking that the two keys to a perfect tension coil are:

1. Applying the correct tension constantly during the winding process
2. Keeping the wraps close while winding (assuming you want a constant contact coil)

For the engineers out there…

Am I correct that the tension needed is something close to the yield strength for the material - i.e. enough to plastically deform the material just a tiny amount?

Thanks in advance

Setanta

 

[Jaaxx]

I'm no guru, but I always wind under tension. I have a clamp on the bench and I use some custom winding tools. Obviously my tension is not precise because I do it by feel, but I get excellent results.

 

[Xhalin]

I've used a coil winding tool and I know for a fact there is low tension- lower than when I manually wrap anyways.....

But I still get great results. Didn't realize that tension was so important- I was taught that minimal gappage between coils is the key...

 

[OBDave]

Do a search for user @MacTechVpr - this man is the unquestioned tension-coil guru...

 

[pulsevape]

Does tension wrapping really give any real markedly noticable improvments in the vape? is it worth the trouble.....how does it improve the vape?also is it something that is only effective when you're vaping low sub-ohm.

 

[OBDave]

Does tension wrapping really give any real markedly noticable improvments in the vape? is it worth the trouble.....how does it improve the vape?also is it something that is only effective when you're vaping low sub-ohm.

I've found after experimenting with the Coilmaster/Kuro Coiler winding tools that it's easier to get an installed tension coil to heat evenly, and they tend to stay taut a little better. Not entirely sure it's worth the extra hassle, but since I'm only rebuilding once every 2-3 weeks I feel it's not too much extra effort to put in...

 

[Ryedan]

Does tension wrapping really give any real markedly noticable improvments in the vape? is it worth the trouble.....how does it improve the vape?also is it something that is only effective when you're vaping low sub-ohm.

FWIW, I've done it and didn't find it made any difference to my vape. It does make the coils stay where you wrap them much more than non-tensioned builds, but I didn't notice any benefit from doing it that way instead of by squeezing hot coils together gently.

These days I've also almost completely gone to non-contact coils after using them in temperature protected builds and liking them. This is with RDAs and RTAs at between 25-60 watts. It might well all be different with lower power builds. Lots of variables in this stuff.

Definitely look up @MacTechVpr for more info. IMO he's the one who knows the most about this process and it might work better for you than it did for me.

 

[MacTechVpr]

Does tension wrapping really give any real markedly noticable improvments in the vape? is it worth the trouble.....how does it improve the vape?also is it something that is only effective when you're vaping low sub-ohm.

Within the same geometry (space) you can concentrate more power with a microcoil. Problem is when a microcoil is just close contact (gaps) it oxides inefficiently. Tends to send the output hot. Defeats the purpose of concentrated power as you're just venting more to air from the high side of the coil. No, you need to oxidize the coil to lock in the advantage and keep it from going hot. Too hot, easy to do on the other side, and the wire so stressed will go hot post-to-post. So there's a middle ground where electron flow smooths out to what you would see in a well separated open wind. Now you have proper insulation. Then you have concentrated power and stable resistance. That's what strain does…enable rapid uniform oxidation. Torching deposits soot on the wire which can inhibit oxidation. Carbon is conductive it can destabilize resistance sending res high in op as power is applied and current finds pathways through it short. But alumina oxidation is an effective insulator and builds a stable route for electron flow. That's the sum up.

I would add that coilers do not impart strain into wire. They can be annealed into contact but you're starting with a spaced wind. It's tedious and diff to achieve balance on duals. Why not just start with one that's as tight as nature will get it. Less fiddly.

Get tensioned!

Good luck.

 

[Saddletramp1200]

Sometimes I hate me. Only physical stress on the wire is the two points where the wire is not supported by the atomizer polls. Add whatever the combined weight of the wick & juice. Gravity takes over. Gravity is always there.
The weight of the two guarantees failure at some point.

 

[Mike H.]

I more or less just wind somewhat tight to give a more accurate ohm reading...Notice when you hand wrap, for example, on a 1/8 drill bit or precision screwdriver, and the coils ends up actually slightly larger and slides off with ease?....This effects the ohms...If it was tight, the inside diameter is actually 1/8 of an inch (on my example), not larger giving you a different ohms reading than the formula says it should be...A tight coil shouldn't just slide off with zero resistance...I tend to have to twist the bit a little to get the coil off.

I do that to all my coils rather its a micro coil or a spaced apart one.

 

[Saddletramp1200]

I more or less just wind somewhat tight to give a more accurate ohm reading...Notice when you hand wrap, for example, on a 1/8 drill bit or precision screwdriver, and the coils ends up actually slightly larger and slides off with ease?....This effects the ohms...If it was tight, the inside diameter is actually 1/8 of an inch (on my example), not larger giving you a different ohms reading than the formula says it should be...A tight coil shouldn't just slide off with zero resistance...I tend to have to twist the bit a little to get the coil off.

I do that to all my coils rather its a micro coil or a spaced apart one.

Dude, get a book. Metal products are really fascinating. If the wire was hot it changes & will conform more than cold. Kind like peeing in summer as opposed to winter.

 

[Mike H.]

Dude, get a book. Metal products are really fascinating. If the wire was hot it changes & will conform more than cold. Kind like peeing in summer as opposed to winter.

So you wrap with the wire red hot?...lol

 

[Saddletramp1200]

So you wrap with the wire red hot?...lol

I get the humor, but I have. Torch, vise, wire, mandrel for size. Yep.

 

[Mike H.]

I get the humor, but I have. Torch, vise, wire, mandrel for size. Yep.

I dont have that much enthusiasm...Maybe an experiment for me at some point but for now when i build a micro coil and i hold it up to the light and cant see light between the coils, im pretty satisfied with it.

I had fun with this one..13 wraps of 30g for 2.7 ohm on a kanger evod single coil head.

 

[Saddletramp1200]

I dont have that much enthusiasm...Maybe an experiment for me at some point but for now when i build a micro coil and i hold it up to the light and cant see light between the coils, im pretty satisfied with it.

I had fun with this one..13 wraps of 30g for 2.7 ohm on a kanger evod single coil head.
View attachment 21339

I don't see any defects in size or position. Should work quite well.
Oh, we have a machine shop. Can measure to One Millionth of an inch. I don't even what to know!
All this is fun for me.

 

[MacTechVpr]

Sometimes I hate me. Only physical stress on the wire is the two points where the wire is not supported by the atomizer polls. Add whatever the combined weight of the wick & juice. Gravity takes over. Gravity is always there.
The weight of the two guarantees failure at some point.

I dont have that much enthusiasm...Maybe an experiment for me at some point but for now when i build a micro coil and i hold it up to the light and cant see light between the coils, im pretty satisfied with it.

I had fun with this one..13 wraps of 30g for 2.7 ohm on a kanger evod single coil head.
View attachment 21339

ST, Mike I intro'd the adaptation of strain to winding now almost two years ago a few months after SxD came up with the contact coil. The primary purpose to bypass the need for hit-or-miss torching and manual compression. It's inexact and leaves gaps mostly not visible to the naked eye. They do result in apparent hot spots; sometimes, not so much.

But here's the deal. Regardless of how many inconsistencies, thickness variations in wire, etc. tension flattens them out. It gets the wire as close as nature permits and that's when pulsing at low-V levels stands the best chance of laying in enough microns of alumina. Now here's the real killer. If you vape at low volts even if you don't nail it it's usually good at low volts while vaping. It's just enough to insulate the surface…BINGO, complete circuit. BUT…up the power and electrons will jump that thin layer. That's where tension comes in. Strain let's you really easily get the optimal contact between turns for pulsing. A huge advantage which lets you easily oxidize a durable insulating surface. I vape .3Ω, 24AWG, 2.5mm, we're talkin' 60W straight mech. Like clouds and flavor. The tight concentration gives powerful vapor density which I can then diffuse with enough airflow for all the volume that I want. THEN…no shorts. Period. Min. a month of operation with nary any visible corrosion on the wire. What that brings ya fellas is a consistent vape. Yeah, all the time.

Can't say enough for it, cause it just works.

Good luck all.

 

[MacTechVpr]

I've used a coil winding tool and I know for a fact there is low tension- lower than when I manually wrap anyways.....

But I still get great results. Didn't realize that tension was so important- I was taught that minimal gappage between coils is the key...

Yes, they do work. And getting symmetry is a first step to smooth electron flow. A consistent wind does help normalize internal strain somewhat. Oxidation gets them more rigidity which deters warping from repeated heat load in use. Not enough tho and the heat is greater than the energy (heat) used to create the wind and distortion starts to take hold. So for one thing you don't see the consistency of operation (res) as the wire is disfigured potentially shorting. Gaps, eroded oxidation, corrosion all the things that result from heat stress with inadequate or imperfect oxidation results in more gaps across which electrons can jump souring the vape just like a loose coil connection.

Point being. Yep, we can wind a coil that looks great. Works great from the jump. But its function that matters, in operation.

Good luck all.

 

[Saddletramp1200]

ST, Mike I intro'd the adaptation of strain to winding now almost two years ago a few months after SxD came up with the contact coil. The primary purpose to bypass the need for hit-or-miss torching and manual compression. It's inexact and leaves gaps mostly not visible to the naked eye. They do result in apparent hot spots; sometimes, not so much.

But here's the deal. Regardless of how many inconsistencies, thickness variations in wire, etc. tension flattens them out. It gets the wire as close as nature permits and that's when pulsing at low-V levels stands the best chance of laying in enough microns of alumina. Now here's the real killer. If you vape at low volts even if you don't nail it it's usually good at low volts while vaping. It's just enough to insulate the surface…BINGO, complete circuit. BUT…up the power and electrons will jump that thin layer. That's where tension comes in. Strain let's you really easily get the optimal contact between turns for pulsing. A huge advantage which lets you easily oxidize a durable insulating surface. I vape .3Ω, 24AWG, 2.5mm, we're talkin' 60W straight mech. Like clouds and flavor. The tight concentration gives powerful vapor density which I can then diffuse with enough airflow for all the volume that I want. THEN…no shorts. Period. Min. a month of operation with nary any visible corrosion on the wire. What that brings ya fellas is a consistent vape. Yeah, all the time.

Can't say enough for it, cause it just works.

Good luck all.



View attachment 21358

It's D, (all the above).

 

[Saddletramp1200]

Know what a 4 angle valve job is? The 4th angle is getting someone else to do it!

 

[MacTechVpr]

Know what a 4 angle valve job is? The 4th angle is getting someone else to do it!

Yeah, I hear ya. I was gonna explore all the great stuff I was seein' on vape forums all over. But you still gotta get over when you start. And I went nuts those first few weeks tryin' to do like anybody else…windin' wire on a wet noodle, 6-wraps over silica for Vivi Nova's. I knew there was better but I did what everybody else was doin' just thinkin' well, there's gotta be somethin' to this. Almost didn't make it. LOL It's then when we need a metric and that's what I'm tryin' to pass on here. A 30 sec to wind, no short, <6 pulses and a reliable vape. Goes like this…



Tap me on the shoulder if I can lend a hand. Oxidizing these when strained properly to max contact is just as important as the wind. And often, where most fail. If not insulated whether a close or tensioned contact, they'll go hot. Where they idea comes from that microcoils aren't worth it is just missin' info on why they do.

Good luck all.

 

[Saddletramp1200]

I see these coil winders people are selling. I got the $2.17 Fast Tech graduated S.S. Pole thingy. I look at it like this. If I can't wind a coil, I'm either too drunk, or not drunk enough. I got almost 1/8 of a mile of Kanthal of different sizes. I am confident I can get it right with practice.

 

[MacTechVpr]

I see these coil winders people are selling. I got the $2.17 Fast Tech graduated S.S. Pole thingy. I look at it like this. If I can't wind a coil, I'm either too drunk, or not drunk enough. I got almost 1/8 of a mile of Kanthal of different sizes. I am confident I can get it right with practice.

Close is only good for horseshoes 'n hand grenades. But I wish ya luck whatever ur vapin'.

 

[Saddletramp1200]

I build a coil to my specs, tug it tight with the needle nose & add a wrap if needed. It's all perfectly legal.

 

[Mykline]

Well I know MacTechVpr and when I first started vaping is when I met him. He taught me how to do the tension coil and the first one I wrapped over a year ago is still in the atty I made it for. I used it for a couple of months and moved on to other atty's but I know I could put some juice in the other atty and it will still vape with that coil with no problems. It even still has the same wicking material in it.

 

[MacTechVpr]

Well I know MacTechVpr and when I first started vaping is when I met him. He taught me how to do the tension coil and the first one I wrapped over a year ago is still in the atty I made it for. I used it for a couple of months and moved on to other atty's but I know I could put some juice in the other atty and it will still vape with that coil with no problems. It even still has the same wicking material in it.

Thanks M. I know it's such a foreign principle in vaping that there are other forces in physics that could make our vape better. In this case the fact that strain changes the physical characteristics of wire itself improving its potential for efficiency. Or that in that stretched condition oxidation or insulation of the wire better protects it from shorts. More importantly that without proper insulation breakdown voltage is exceeded in a contact (close or touching) coil and you no longer have a complete circuit but something akin to a loose connection. I guess some folks must sell coilers…without explaining how to get the latter…like sellin' a car without the steering wheel. Oh well.

As long as we continue looking at winding and rebuilding as a new invention every time, the vape will suffer. I'd rather use a ruler 'cause I guess I'm just lazy like that. So thanks for kickin' in M. It takes time, I know. I've only been at this two years and we had seven years of wind it any 'ol way before the microcoil.

Good luck bro. Vape on.

 

[MacTechVpr]

Hi folks,

Has anyone actually figured out how much tension you need to apply to make a successful tension coil? I've seen the figure of 7lbs in one thread but I don't know how that value was arrived at. That said, looking at optimal tension for winding copper wire and comparing that to kanthal it seems (to my VERY limited engineering knowledge) to be in the ballpark.

I realise that the exact amount will change depending on that gauge of the kanthal used, and to a lesser extent the particular kind of kanthal used and I'm guessing that nickel/nichrome/titanium builds will require less tension than kanthal, so what I'm really looking for is a ballpark figure for the sort of gauges typically used in making coils.

Just while I'm here - a couple of other questions for those that might know this sort of thing…

For the tension coil gurus…

Am I correct in thinking that the two keys to a perfect tension coil are:

1. Applying the correct tension constantly during the winding process
2. Keeping the wraps close while winding (assuming you want a constant contact coil)

For the engineers out there…

Am I correct that the tension needed is something close to the yield strength for the material - i.e. enough to plastically deform the material just a tiny amount?

Thanks in advance

Setanta

The goal I talk about is using the leverage of a spool and pin vise to get the end turns to closest proximity. Basically loose and you present gaps that won't oxidize or not enough. Too much however and the wire's not merely stretched but strained. Resistance goes up and way up in operation. So, yes, the wind must be consistent. Amazingly it's pretty obvious to peeps that never wound a coil at all when it happens. If you try it start out just applying enough tension to form the wire. About as much as you'd use to hand wind. Start adding more tension as you go. You'll find the point that turns will conform exactly to the bit. They will not expand, not in diameter or turn-to-turn. It's just a bit tighter that stabilizes the internal strain balance, just enough for a kind of metal memory to take hold. In this tight and resilient condition the wire must oxidize uniformly. Gaps have been minimized and the relationship of turns is as tight as you can get. That is how you make a complete circuit from a contact coil.

Good luck all.



p.s. Lateral compression (of wire cross-section) yields to strain (elongation).

 

[Setanta]

The goal I talk about is using the leverage of a spool and pin vise to get the end turns to closest proximity. Basically loose and you present gaps that won't oxidize or not enough. Too much however and the wire's not merely stretched but strained. Resistance goes up and way up in operation. So, yes, the wind must be consistent. Amazingly it's pretty obvious to peeps that never wound a coil at all when it happens. If you try it start out just applying enough tension to form the wire. About as much as you'd use to hand wind. Start adding more tension as you go. You'll find the point that turns will conform exactly to the bit. They will not expand, not in diameter or turn-to-turn. It's just a bit tighter that stabilizes the internal strain balance, just enough for a kind of metal memory to take hold. In this tight and resilient condition the wire must oxidize uniformly. Gaps have been minimized and the relationship of turns is as tight as you can get. That is how you make a complete circuit from a contact coil.

Let me see if I have the concept correct - The way to tell that the tension is correct is when the coil, after the tension is released, does not unwind/expand away from the object you have formed it around?

I ask because I have a concept in mind for a VERY simple jig to make tension coils which uses a weight to apply the necessary tension to the material. Nothing that I intend to manufacture/sell - if it works I intend to release it as open source hardware - which is why I need to know roughly how much tension is required. If it's less than, say, 10lbs, then my idea is a practical possibility - much more than that and it's a non starter.

Setanta

 

[MacTechVpr]

Thanks for the comeback Setenta. Your posts suggest you understand D/C enough to get your arms around some of the principles I talk about. I've posted some basics here. More than 1500 posts on the concepts and mechanics on ECF. Recently a number of qualified experts have affirmed the benefits and necessity of Kanthal oxidation and it's taken time to get there. Pity. We almost have regulation upon us. Having worked in int'l commerce, to equate vape consumption with environmental jurisdiction (public health), the potentials for associating an aspiration as a taxable regulatory premise for consumables has far reaching consequences. Why I insist on advocating tension winding to both new and experienced vapers.

If you're interested in automation strongly suggest you try to learn to hand turn wire with a pin vise, the most direct controllable way to impart strain. The point of adhesion (closest proximity) is more readily discerned. Easy to make many this way and evaluate them for oxidation and performance. The best test S is at initial pulsing of the coil. Assuming no distortions of strain are introduced in the set (termination) t.m.c.'s will typically fire uniformly without thermal variation or anomalies (cool or dark spots) within one or two pulses (only initially center out for a sec. fraction). Not much beyond this you have initial alumina deposition and for most users this is satisfactory.

I don't believe you will find a weight standard. The point between loose contact and over-strain is not wide but ample. However, it varies for every gauge and wind spec. Any mechanical device would have to be versatile enough to accommodate such differences. Further individual wire sections can have significant variation. Although mm diametric fractions these are the very causes in part of thermal variation. I found hand winding the most practical means to adjust for this on the fly by visual and tactile detection. But having motion control issues I would only encourage you to research a basic device that can impart strain. Many of us cannot hand turn wire consistently and some of us are compromised with other issues affecting motor skills.

If I can be of any help or you'd like to share your results post them here. Or, PM me if I can help.

Best of luck.

 

[Setanta]

If you're interested in automation strongly suggest you try to learn to hand turn wire with a pin vise, the most direct controllable way to impart strain.

This is the method I use currently to produce my own coils and, what I am looking at is more or less an extension of this method to make it even easier and improve consistency. I suffer from peripheral neuropathy which means I have a loss of sensation in my hands. This makes it difficult for me to maintain anything like consistent tension even using a pin vice so I'm trying to come up with a solution to this problem rather than trying to automate production.

I don't believe you will find a weight standard. The point between loose contact and over-strain is not wide but ample. However, it varies for every gauge and wind spec.

I realise this but was simply looking for a ballpark figure (if such a thing is possible).

The device I have in mind is extremely simple - similar to a 'Coiling Gizmo' but somewhat optimised towards creating tension coils. The actual method can be emulated using a pin vice, mandrel and weight as follows...

Take the mandrel and a length of kanthal and clamp them both into the pin vice as you would normally. Attach a suitable weight to the free end of the kanthal. While holding the pin vice, place the free end of the mandrel on a fixed surface (tabletop) such that the weight is hanging freely. Angle the mandrel/pin vice a couple of degrees down (towards yourself, not the table) to ensure the wraps will remain in contact with one another. Rotate the pin vice the required number of times to create the desired coil. Either remove or support the weight before cutting the legs of the coil to length.

It's rather harder to explain than it is to do

The device I have in my head includes a support which would be clamped to a tabletop which allows adjustment of the angle and a crank handle to provide better leverage against the weight. Hopefully I'll have some illustrations soon to show what I mean and invite comments on the practicality of such a device.

Setanta

 

[MacTechVpr]

This is the method I use currently to produce my own coils and, what I am looking at is more or less an extension of this method to make it even easier and improve consistency. I suffer from peripheral neuropathy which means I have a loss of sensation in my hands. This makes it difficult for me to maintain anything like consistent tension even using a pin vice so I'm trying to come up with a solution to this problem rather than trying to automate production.



I realise this but was simply looking for a ballpark figure (if such a thing is possible).

The device I have in mind is extremely simple - similar to a 'Coiling Gizmo' but somewhat optimised towards creating tension coils. The actual method can be emulated using a pin vice, mandrel and weight as follows...

Take the mandrel and a length of kanthal and clamp them both into the pin vice as you would normally. Attach a suitable weight to the free end of the kanthal. While holding the pin vice, place the free end of the mandrel on a fixed surface (tabletop) such that the weight is hanging freely. Angle the mandrel/pin vice a couple of degrees down (towards yourself, not the table) to ensure the wraps will remain in contact with one another. Rotate the pin vice the required number of times to create the desired coil. Either remove or support the weight before cutting the legs of the coil to length.

It's rather harder to explain than it is to do

The device I have in my head includes a support which would be clamped to a tabletop which allows adjustment of the angle and a crank handle to provide better leverage against the weight. Hopefully I'll have some illustrations soon to show what I mean and invite comments on the practicality of such a device.

Setanta

Thanks for the details Set. I want to say about 7 lbs. hanging weight as a starting point. Quarter lb. increments would be useful. It is possible to augment a hanging weight with hand or finger pressure. Will vary by gauge and wind. Hands can exert considerable force and a great deal of sensitivity. But for folks like us, it can be hard at times. Looking forward to your feedback here and advance.

Good luck.

 

[Rommel]

When i get back home im gonna take some pics how i achieve accetable tension without tools. Its all in the technique and some finger strenght

 

[MacTechVpr]

When i get back home im gonna take some pics how i achieve accetable tension without tools. Its all in the technique and some finger strenght

You're a better man than I Rom if you can pull that off. LOL Yeah! Show us the pics.

But it is about strain ya know. All wire's strained. Balancing wire resistance (stress) I pitch tension winding 'cause it's easy without any prior skills. Also to get peeps quitting quickly to that oh-wow moment of sticky-tight without all the blindin' 'em with science. What do they care that alumina oxidation inhibits shorts and the hot hit? So not doubting ya. Actually worked with a few pro builders who had the hands to do it consistently even with fat wire. When you get it, a good alumina depo and it behaves like a real insulated wire...vapor density does go off the rails.

G'luck Rom.

 

[Rommel]

Dammit, the pictures my memory is good you know, if we overlook the fact that its utter shit.

But yeah, with 26 gauge n80/kanthal tensioning with your fingers can be done

 

[Saddletramp1200]

Dammit, the pictures my memory is good you know, if we overlook the fact that its utter shit.

But yeah, with 26 gauge n80/kanthal tensioning with your fingers can be done

.26 is a good choice. .24 is hard to conform in smaller Attys.

 

[MacTechVpr]

Well I know MacTechVpr and when I first started vaping is when I met him. He taught me how to do the tension coil and the first one I wrapped over a year ago is still in the atty I made it for. I used it for a couple of months and moved on to other atty's but I know I could put some juice in the other atty and it will still vape with that coil with no problems. It even still has the same wicking material in it.

Mike, great catchin' up widja the other day. Hope I didn't crank up the heat with the misses.

Hail me when ya can.

Good luck.