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Author Topic: Air Temp Nitinol  (Read 206172 times)

gadgetmall

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Re: Air Temp Nitinol
« Reply #105 on: November 04, 2012, 10:30:48 PM »
Hi tom . Apparently some one is follow my thread and getting grants for this exploration . Chinese no Doubt . Anyways very good . It is now frost and cold as all heck . I have not had the time to explore the ambient motor i built but will very soon . I do see my wires turn to speggittii and they also like the cold to relax . they instantly get hard in the house . very cool stuff .

Gadget .

johntee

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Re: Air Temp Nitinol
« Reply #106 on: November 09, 2012, 09:05:02 PM »
Hi Gadgetmall,


I'm a bit late in this thread.


In an earlier thread you quoted "looks like any wire kelloggs is selling needs freeze spray or liquid nitrogen to get soft. his air temp wire is just that . it stays stiff as steel in 33f and above  "


Is their AirTemp wire so useless? Also in your experience what is a realistic temperature for their advertised AirTemp wire to become sloppy soft? 


Likewise does this wire change to its rigid state at their indicated 70 degrees C.


I always thought they were a reputable company.


Who from your experience supplies the best priced wire that is sold in smaller lengths


Thanks for you time,


John

johntee

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Re: Air Temp Nitinol
« Reply #107 on: November 12, 2012, 11:11:43 AM »
Hi everyone,

Here's a rather nice attached article on Nitinol wire and using it. It also has a nice easy Pulse Width device for more effective "training" of Nitinol plus much more.

It originally came from Talking Electronics web page but I converted it to Adobe Pdf for easy reading. Full content credit goes to the articles originator.

Hope this is of use,

John

gadgetmall

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Re: Air Temp Nitinol
« Reply #108 on: November 15, 2012, 08:40:41 AM »
Hello johntee . Welcome . If you keep reading you will see my supplier . he sells a 40 foot roll. It is the best and i have tried them all . The Main problem with k's wire it takes too much Energy to make it do what can be done with just the energy that is available from the environment. This is a fact .

Thanks for the PWM link . I have mine wire perfected but a pwm wold make it that much simpler .

Gadget

johntee

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Re: Air Temp Nitinol
« Reply #109 on: November 15, 2012, 11:17:30 AM »
 Hi gadgetmall,
 
 Thanks for your time in replying to my post. I've read all your posts and found your link to the ebay seller but unfortunately his products show as SOLD. Just my bad luck.

 Do you post regularly with links to the good stuff?
 
 For reference, I have tried the Kellogg’s nitinol wire product and likewise found it less than good as a SMA material. Its ability to change or react to temperature change is useless.
 
 I can't see how they get away with calling, and selling it as Shape Memory Alloy for the one they sold me as such seems to behave like the SuperElastic type ( I think  that's correct) which is  oven heated to 530c and thereafter remains in that ridged condition. It will not react or reshape thereafter at lower temperatures as demonstrated on the many videos. I used a variable 'Digital Temperature Controlled Heat Gun' for heating the wire so it's pretty accurate in that area.
 
 I see from your posts that you've perfected your 'training' with capacitors / current, brilliant work !! 
 
 I actually supplied the Adobe Acrobat pdf converted article from Talking Electronics for the convenience of our members, that allows them to keep a hard copy on their PC for easy reference, also the PWM seems a pretty cool way of conditioning / training the nitinol wire for those not as proficient as yourself.
 
 Thank you once again gadgetmall, I'll have to wait patiently for your lead to some good characteristic SMA. My brain cells have been working overtime just recently on constructive methods of utilizing it for the benefit of all. I will succeed. That's what our site is all about.
 
 Kindest regards,
 
 John in the UK  ;)


"People laugh at me because I AM different, I laugh at them because they are all the same
 
« Last Edit: November 15, 2012, 11:19:03 PM by johntee »

gadgetmall

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Re: Air Temp Nitinol
« Reply #110 on: November 16, 2012, 02:37:50 PM »
I see there is no more sellers selling the good stuff . I have a lot of it and made sure i would never run out of it . I have bought these and they are nice wire . They are already treated though and will return to the u shape everytime ,http://www.ebay.com/itm/5-X-Rectangular-Thermally-Denatl-Activated-Nitinol-Arch-Wires-Best-price-/200714255085?pt=LH_DefaultDomain_0&;hash=item2ebb807aed

I have these also .http://www.ebay.com/itm/DENTAL-ORTHODONTIC-WIRES-THERMAL-NITINOL-RECT-HURRY-/310391441334?pt=LH_DefaultDomain_0&;hash=item4844c587b6

 they are very strong but you need ice water . they do get soft . you get 10 per pack on all the medical dental wires .

I have also tried the other ones no marked as thermal and they work you have to anneal them .

get the biggest size 21 x 25  and also the small ones work really well . The one i like the most is 14 x 25 thermal activated upper . They will turn to noodles in cold water and return to oval U shape in warm air and body temperature . i carry one in y pocket and have amazed quite a few people .

I may just have to sell some of my special wire by the foot . I really do not know where to get this ultra pure grade wire cheap . I know Jd medical wants an arm and a leg for three feet of the wire i bought . 85 us for three feet . Plus shipping . Yeaks.  I can do half that easy .My wire can change in just a 25 degree difference and as you read many different temperature ranges well within Normal Ambient air temps thus we don't need to expend any energy other than what God supplies after it is trained .

johntee

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Re: Air Temp Nitinol
« Reply #111 on: November 16, 2012, 07:22:11 PM »
Hi gadgetmall,

Thanks for your reply. For my device to work at its most efficient I need wire that will be 'noodle sloppy' in cold ground water at around 40 to 55 degrees F and have a fast transition speed to 'rigid' at 70 to 75 degrees F.

On the above information which of the ones you mentioned in your post above would fall into that temperature category?

I notice on on the first link you gave me to:- 

http://www.ebay.com/itm/5-X-Rectangular-Thermally-Denatl-Activated-Nitinol-Arch-Wires-Best-price-/200714255085?pt=LH_DefaultDomain_0&;hash=item2ebb807aed

the Ebay seller just states they are  "THERMALLY ACTIVATED" dental Nitinol wires, there is no mention or indication of transition temperature. If these are suitable which from your experience would be the best sizes to order from those he lists on his Ebay page?

I'm a 66 year old retired pensioner now so I have to spend very carefully these days.

RE: "The one i like the most is 14 x 25 thermal activated upper . They will turn to noodles in cold water and return to oval U shape in warm air and body temperature . i carry one in y pocket and have amazed quite a few people."

I've searched the web for these but cannot specifically locate anything which exactly fits the bill as far as temperature goes. Do you by chance have any lead to the person who is selling these? I do need something which will "turn to noodles in cold water and return to oval U shape in warm air and body temperature"

Sorry, I ask a lot of questions  of you  but I feel you are the most experienced person to guide me on Nitinol use. Many thanks again,

John in the UK.




"People laugh at me because I AM different, I laugh at them because they are all the same"   
 :)

gadgetmall

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Re: Air Temp Nitinol
« Reply #112 on: November 16, 2012, 10:05:27 PM »
Hi. Yes that is the number one problem with finding Nitinol. No one will tell you exactly at what temp it changes . That is because before be there was no published experiments with Ambient Nitinol or there was none until now.

I have the kind that can be trained exactly like that and it is 0.020 diameter . No one is selling it anymore .There is only one place and you have to be rich and that is JDmedical or Nitinol.com . Both of them are more expensive than it's weight in platimium.
As i said the Thermally activated arch wires are the closest thing. I paid 10 cents a pack of 10 long wires . Now they are very much more than that. I have not experimented with them other than take them out of the pack and see that they will get soft in water around 36 37 F  and get strong somewhere near 75-98.6 .. It is cold here in NC but not yet below freezing and still in the 40's 50's .the only wire that changes is the original wire in the 40 foot rolls. It can be trained for  air temps unlike that fake stuff Kelloggs sells. That is not air temp wire . That is not even close to what i have or the thermal arch wire. .
Sorry if i can't help . I can sell a bit of mine but this stuff is very valuable to me . Once you see it work it is one of those things that just needs to be in the safe.

I do sell pieces on craigslist but they  sized about 12 inches for 5 usa postage included . It can be unanealed so an experimenters piece. I cut them up in 2 inch pieces and anneal them for family and friends locally . I also keep several pieces in my pocket in the corner of my wallet . I make small trick wires with latex loops so they don't get lost when you drop them .http://eastnc.craigslist.org/mat/3363835928.html

Gadget

johntee

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Re: Air Temp Nitinol
« Reply #113 on: November 17, 2012, 12:24:59 AM »
Hi gadgetmall,

Thanks for your speedy reply. If you are willing to sell me some of your wire I'd appreciate that.  I would need 5 foot (60") to evaluate my current project if that is possible. I don't have any capacitors for training the wire, only a variable temperature heat gun to 650 degrees C.


Therefore any exact help using that to train the wire to the cold water / room temperatures I mentioned in my last post would be appreciated

I can pay you by PayPal, although I have never actually paid an individual direct ( Ebay only ) so you'd need to give me details of doing that.

I have just topped up my PayPal account tonight from my bank but the funds will not clear until 21st November so I'd need to wait for that date before I could process the transaction.

I live in the United Kingdom so you need to add postage etc although my last stuff (crap) from Kelloggs came by ordinary letter post.

If everything is OK with you please get back to me with details.

Many thanks again,

John in the UK


"People laugh at me because I AM different, I laugh at them because they are all the same"   

Tom Booth

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Re: Air Temp Nitinol
« Reply #114 on: December 03, 2012, 07:33:43 AM »
Just some ideas and observations: In general, most of what I've seen as far as uses for Nitinol (power generating uses) involves direct contact with water. My impression is that it does not conduct heat to or from the air as readily or rapidly as it does with a liquid.

So what I've been wondering is if Nitinol used in some power generating application involving heat exchange with AIR might not benefit by having the wire clad with some kind of aluminum or stainless steel fins to assist or speed up heat transfer. This is not uncommon. All sorts of air conditioners, refrigerators, heat pumps etc. use such a method (usually on pipes or tubes, but why not wire?).

I was thinking of something along the lines of these "Wire Wound Fin Tubes" such as illustrated and described on these pages:

http://www.taaming.com/

http://www.indiamart.com/geiindustrial-systems-ltd/products.html

This might increase heat exchange between the air and the Nitinol while remaining flexible.

gadgetmall

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Re: Air Temp Nitinol
« Reply #115 on: December 03, 2012, 02:06:26 PM »
Tom . I have had no time to test this YET but i will . The design will use ground temp water bath for the temperature differential using just brass pulleys .
If i can find something finned i would try it . .

Air temp nitinol need only 25 degree difference and it will Immediately phase change around brass ,aluminum or copper  wheels without water in the above ground section. it is metal and can absorb the temperature of the air just as good by itself but metal wheels,especially in 21 degree air like we had a few days here where everything was cold . ..
Cold season appears not a problem but summer days like we had this year(116f) will need some serious cool water underground to touch and a finned wheel is a good idea at least for the below ground area.

i did a small test in 35 degree out side air with an excavated heat tube(produces steam) and of coarse that works very will with just brass pulleys in air .

AI have a lot of work to do . 

Tom Booth

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Re: Air Temp Nitinol
« Reply #116 on: December 03, 2012, 08:30:48 PM »
Hi, I wasn't thinking in terms of your particular application. I don't know as a wire with aluminum fins would be able to go around a wheel. I was thinking more along the lines of a hot air engine where there would only be hot and cold air contact. Something like the design I posted earlier where hot and cold air would be passed across a nitinol wire (or wires) or springs by means of a Stirling type displacer arrangement to move the air.

The problem being that from my general observations, nitinol does not seem to respond quickly to air temperature changes. From what I understand or have read, such fins can increase the rate of heat exchange several times over in various other more conventional applications like heat pumps, air conditioners etc.

johntee

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Re: Air Temp Nitinol
« Reply #117 on: December 03, 2012, 10:08:22 PM »
Hi Tom,

You have a very fertile brain, a great quality.

Personally I'm not too sure on the actual characteristics of Nitinol wire yet, I have some on order. Therefore I would open up such concepts as yours to our more experienced members for evaluation and feedback.

Thanks for your posting,

John

Tom Booth

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Re: Air Temp Nitinol
« Reply #118 on: December 05, 2012, 12:40:34 AM »
Thanks,

Unfortunately, at the moment, my brain is much more fertile than my bank account, so I haven't gotten around to getting my hands on any Nitinol as yet. I could certainly afford the Nitinol. relatively cheap stuff. Building the engine to put it in and test such a concept however is a different story.

Jon J Hutton

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Re: Air Temp Nitinol
« Reply #119 on: December 30, 2012, 05:53:45 PM »
I am amazed that Nitinol has not received more attention. Even if you can only get a few watts from a temperature gradient of 50 degrees or less, this could be multiplied. This is bound to make a huge comeback since its discovery. Good work. This has more potential than solar if the prodution price could drop. Is the air changing Ni dopped with Co or just Ni ?
P.S. I lived in Oklahoma for many years and now am a director of a school here in Guatemala. Less than 20 minutes from my house is a huge lake at the foot of an active volcano in the mountains. I took a thermometer with me and the sands of the beach in many places have vents where the temp of the sand stays at a hot 150 deg. F year round. The water just a few feet away during the winter ( winter here is where the temp drops down to 70 but it can get colder at nights. ) is approx 75. Before reading this thread I was considering a sterling app, but now am considering a new approach of a ni engine. Any help anyone could give would be greatly appreciated.