Chance PI coil...

[solmer2]

Hi there,

I need some info (measures) to build this type of coil for the Chance Unit



Does anybody know the measures of this coil? (I mean radius, space between cuts and number of turns...)

Thanks in advance.

[homefire]

Look in here.

http://www3.telus.net/chemelec/Projects/Metal/Metal.htm

http://www3.telus.net/chemelec/Proje...l/New-Coil.jpg

[WM6]

http://www.thunting.com/smf/pi_desig...5978#msg195978

[golfnut]

That coil looks pretty, but I dont quite understand it.

It looks a cow to make


If you pot that lot it will weigh a fair bit..

S

[WM6]

That coil looks pretty, but I dont quite understand it.

S

This is 3-dimensional zig-zag wound coil.

[homefire]

Thanks to WM6, I was able to find these.

The Idea is that this fashion of winding produces less inter wire capacitance and will make for a faster coil.

[solmer2]

Thanks

Hi thanks for your help,

While searching the web I've found a printable for the ultra fast coil as well as detailed info about building the coil.... now I need to find a suitable material... (cardboard is a bit soft and I don't like to made it of wood so I'll try to get a piece of plastic.....)

Thanks again.

[homefire]

Cool Beens! Gotta give this one a try. I know someone else thats been looking for this info as well.

[Al1g]

So how would I go about shielding this coil? Could I fill it with Resin and use paint on graphite? Or would the resin destroy it?

[Comp]

I have built a couple of these,.... I printed out the template, stuck it to a cardboard former,... cut out, and off we go.......
I wound one with 22 SWG copper enamelled,... and one with 24 SWG,... (see pics here,... post 29....) I potted it in resin, then coated with thin, self adhesive copper foil,..... I am using it on a Surf PI board,... but am a bit disappointed to be honest,... inductance, and DC resistance seem ok, but I am getting poor sensitivity,... but I could well have made a BooBoo!!!

The poor results could be due to a fault on my board build, due to the fact that I dont know WTF I am doing,..... but I am working on it??!!??

I will photo the finished ones, if you like, they were lightly 'drizzled' with resin,... then covered with thin copper foil,.... fairly light, and nice and stiff,.. just dont pick owt up!!! LOL!!
{I can post you one, if you PM me your addy, perhaps you will have better luck with it!!}

Cheers, will update as and when, Fred

[golfnut]

Hi if you fill the air spaced fast coil in with resin you will slow it down again.

Steve

[WM6]

Hi if you fill the air spaced fast coil in with resin you will slow it down again.

Steve

You can fill it with polyurethane foam without notable slow down.

[golfnut]

sure, sounds like a plan..

Anyone make a tx coil from mig welding wire spaced with dots of hotmelt..


Anyone use neodymium permanent magnets as a Tx source? much bigger H field than small ocillators..


Or use ferrites to force the magnetic centre to a tighter focus


?
?
?

[DOOLEY]

hello golfnut ,

you mention mig wire , i also thought of this , being that its 0.6mm or 0.8mm dia ,

but , the steel mig wire i think is a deff no no .

however , i did think of using 0.6mm aluminium mig wire at one point , and was thinking of spacing it with heavy 0.6mm nylon fishing line and forming a flat spiral coil.

think i posted the idea on here , asking if aluminium was a good idea , but no one commented , so asumed it wasn't.

i thought it would be as aluminium wire is light , less dense than copper , and not far behind in conductivity , it made sense to me , i was thinking it would be worth trying as there would be less density of metal in the search head , and poss result in a more sensitive coil .

so the questions are :

is nylon a good insulator to use ??

and is aluminium wire a good option ( PI machine esp ! )

[johnandles]

Hi Golfnut, my radio control model aircraft electric motors use neodymium magnets as a rotor,the stator is wound around 3 separate windings, star and other configurations, fired by a dedicated controller,a type of three phase timed pulsed DC?..
I know these magnets are powerfull, how can you pulse the neo magnets and capture the result? Or maybe an idea is by using a very powerfull magnetic field (as per neo's) in a search head and try to capture the result?...but I would suspect the RX would only pick up only the TX high magnetic field.
Just my 2 cents worth.
Regards
John

Quote...

Anyone use neodymium permanent magnets as a Tx source? much bigger H field than small ocillators..


Or use ferrites to force the magnetic centre to a tighter focus


?
?
?[/QUOTE]