disappointment

[satdaveuk]

I did it this way.
Grt Nakky

I like your bit of engineering there Nakky, did it do the job ok

Regards

[satdaveuk]

Fyi
If you dont want to use glue,use an old oven and try bake the coil.
Start low with a test piece let say at 50* and see how long it takes to stick.
Dont do it to high oterwise the lacker of the wire wil desolve it only have to stick
so the coil wil be solid and no more sticky fingers ;-)

Btw winding by hand can be done but slow and à little tighter than a machine winder.

Just my 2 cents

Well the baking goes back donkeys years ago the windng was lumed with wax string as i do then they used to soak wool bandage in varnish and wraped round the coil, after that the hole thing was put into a vat of varnish for 48hrs, then they were baked for a time in a oven, the main reason for this was to stop chatter within the laminations.

My dads well in his 80s now, and has said on more than one occasion why dont we make are detector coils like that, ive promised him the next time ill try it out.
So good on you Tepro, just takes a bit imagination and lisen to them who has experience from many moons ago.

Regards

[nick_f]

That's it! Garrett, not Tesoro.

Hi All,
The link to the Garrett how-to video does not work anymore. I found another link, http://www.youtube.com/watch?v=hUDLXEiIsxI
I think the language is czech or polish, but you get the idea from watching the video...

Regards,
Nicolae

[Tepro]

Fyi
If you dont want to use glue,use an old oven and try bake the coil.
Start low with a test piece let say at 50* and see how long it takes to stick.
Dont do it to high oterwise the lacker of the wire wil desolve it only have to stick
so the coil wil be solid and no more sticky fingers ;-)

Btw winding by hand can be done but slow and à little tighter than a machine winder.

Just my 2 cents

[der_fisherman]

Simple turns counter for coil making

I often loose count while winding a coil.

Can anybody recommend a cheap, simple turn counter?

Tinkerer

I don't know if you are still interested in a very simple answer, but I bought some really cheap electronic counters on ebay, added two thin wires so that I could add an external micro-switch.
My first attempt did not count correctly because the switch needs about a 50:50 on to off time to count exactly right.
So I placed the D shape on a bearing so that the half round of the shape holds the micro-switch closed for about 50% of the time/turn. Works great.
See the picture for the ones I bought! I got two for about $5 if I remember correctly. I placed the wiring so that the button still works.....there was even a spare battery included for each one!
If you want any further infos just ask.
Regards
Andy

[golfnut]

what can a dude do, dude.

Hi, I get product from these ..

http://www.ecfibreglasssupplies.co.uk/c-819-release-agents.aspx

Ive used the release film, There is pva, waxes etc - these guys sell stuff that works.

S

[WM6]

Noble work nakky!

[nakky]

I did it this way.
Grt Nakky

[satdaveuk]

Its all trial and error me old mate, I made loads of coils before i got it right, its nice to see others trying different angles, thats good for all of us.

[Jerry]

I do not understand your disappointment. That coil looks pretty nice to me. Also you took another approach and proved that it does work. I think that is success!

I agree with you on the straight sided D coil. I found the same thing and will try a slight curve on my next one.

Thanks for posting your work.

Jerry

Sorry, I wrote this before I read the entire thread. took things out of context Admin can delete if you want.

[Mullihaka]

Nabiul proposed using polyethylene cutting board for coil former. I did.

Using router, I cut 4mm wide and 5mm deep slot around the board. That needs steady hands as the board is only 6mm thick.

I spread 2-component epoxy at the bottom of the slot around the former as proposed somewhere else in the forum. I did it at 10 C, so I hade some extra minutes time before it started to cure.

I had cut the former in 4 pieces like in the picture. When the epoxy had cured, it was quite easy to slid the square part inwards out of the former, and then the rest 3. The big pieces needed some prying with a small screw driver. However, I got the coil out without breaking it or the former.

The former should not have the back of the D straight but a bit curved. The wires did not sink deep in the slot as they did on the belly side of the D. That left the straight part a bit thicker and the inductance lower than calculated.

I think that only one D should be epoxied hard. Having the other D tied with dental floss, taped, shielded and taped leaves it a bit flexible, which is needed to make slight adjustments in nulling. That way most of the circumference can be glued and a small section at the middle of the back of the D left without. Having both Ds rock hard looks difficult to null, as it's more difficult to handle whole D than just adjust a 5cm section of overlapping back of the D.

[Tilladude]

Simon,

Dribble, dribble, dribble, I think I might have to see a Doc. about this.

Yup parchment paper is what I meant and yes you would need top & bottom pieces. I like the idea of using foil, you would jhave to cover and roll over the edges of the boards and maybe use heavy duty foil to keep the wire from tearing it. If you are doing a layered coil you probably wouldn't be going very fast anyway and tearing shouldn't be a problem.

Take care out there,
Dennis

[simonbaker]

Simon,

You could try baking paper, the stuff they sell in kitchen ware shops and such. It doesn't allow the oils and sugars to get through and stick to the metal sheet.

I would wax the boards first then staple the paper down around the edges and go about winding the coil as normal with whatever "thane" you want to use. Then when you seperate the form coil should come out covered on both the paper, trim the extra paper ( maybe leave enough to finish wrapping the coil) and apply the shieding material.

Just some dribblings from my aging grey cells.

Take care,
Dennis

Yes, I know what you mean. I stole some "parchment paper" from my wife's kitchen supplies (again) which I think is same thing. I'm using it for base while making a latex mold of dfbowers coil shell. In that case, it doesn't stick. But you are saying, let it stick, so what, just trim it away. Yes, I see the idea; might do the trick.

What if I put down aluminum foil, let it stick, and then used it to wrap shield -- but I need piece on top also. Problem is wire may get under it if not really fixed down perfectly -- wire rubs along surface.

I feel need something really easy, no fuss.


Thanks for the dribblings.

-SB

[Tinkerer]

Tinkerer,
I converted a mechanical kilometer counter designed for cycling. Eliminate its gears. In order not to rotate his body, hooked to body a small weight that hangs like a pendulum. If you find such device and disassemble it, you'll think of how to convert for turn counter.
When my colleagues asked to repeat my ugly but simple and cheap turn counter, it turned out that the bicycle shops no longer offer mechanical counters, but electronic devices called "bicycle computer". They are inexpensive, easy to reset and can be designed very elegant coil winder because use magnetic sensor. However, the models are not able to show directly the wheel turns, but show the result multiplied by the circumference of the wheel. My advice is you to visit several bike stores and getting to know the capabilities of the proposed devices. You may come across a model that can be integrated in coil winder.

Thanks for the feedback.
I will look up the local bicycle shops for parts.

Tinkerer

[Qiaozhi]

Or you could try this stuff ->

http://www.amazon.co.uk/BakeoGlide-2-Teflon-Sheets/dp/B00175QHTU