Coil wrapping made easy

[6666]

It's actually quite feasible with a flatbed type router ...or similar setup just has to be rigid enough to keep accuracy and repeatability.
The roller idea is great. Might machine up something similar and have a shot.
If it's just to make a single coil, I wouldn't bother but for multiple coils , yeah, great idea.

Cheers

Mdtoday

The "bed" seems simple just masking tape.

[Mdtoday]

That's true, I think it would have to be held with a bit of tension else it would stick to the roller, will have to try it and find out what works best.
The drag knife type action is the part that has to be right too.
The problem of having less friction on the wire feed can be helped along by using a smaller spool of wire, so there are a few simple improvements to the original that would help.
Ill make an attachment for my router and do some experiments see what I can come up with.

[Mdtoday]

I have a lot of spare parts for my 3d printer that can be put to good use.
Like these 6mm threaded parts with teflon inserts you can get off auction sites for around $5 for a pack of 5.


The extruder mechanism has compression springs, the aluminium heater block that takes the above threaded barrel can be machined, so a lot of gear readily available.
Even the brass nozzles are dirt cheap and you could insert teflon into the ends of them for different sized wire, then you can just unscrew and replace with different sizes as required.
Or, just buy 6mm threaded nylon rod cut to same sort of length as nozzle, drill hole to suit wire gauge..

The roller can be covered with thick heatshrink tubing instead of silicone, it would probably work

You could make up a simple stepper motor driven x-y plotter type bed for a reasonable price using 80/20 extrusion etc but it all depends on how far you want to take it.

[Tibuck19]

No idea, I've never made a flat-spiral DD.

Carl, I am going to have Russ from Rwg to make me a flat coil for the Surfpi and MMP, Do you have any suggestions on the best coil ID and OD it should be? he normal makes them on a sheet of sticky paper, Do you know if any sheet(sticky or not) that I can suggest he use so it can also act as a shielding/faraday ? Perhaps have a look at his latest video to see what he has going on. Also Im wondering if a Flat coil has any advantage over a normal mono loop coil I made?

https://www.youtube.com/watch?v=QfoMRPy4bJk&t=1376s

[Tibuck19]

Anyone

[Mdtoday]

Anyone

Hi Tibuck19,

I looked at the original video some months ago but hadn't seen the latest, its quite clever, I did a bit of playing around with it on my cnc with similar set up with medium success, needed more machined parts so I put it aside for a while, too many things on the go...

Don't know of any "sticky" paper with shielding material on, think you would have to spray or paint the shield on the other side, however, you need some space between shield and winding so that adds another criteria of the "sticky" material.

Best diameter depends on what you are looking for, the flat coil's sensitivity / depth is related more to the internal diameter, so I would start with that, so for general use maybe 250 mm inside, out side will end up between 280 to 300 mm depending on choice of wire.
There are so many variables to the question of which is better bundle or flat my experience, once the shield is applied to both types, there is not a whole lot of difference until you get into the realms of nugget hunting and use Litz wire for the coil winding.
I would not use magnet wire wound as close as what the video shows, you need some separation to avoid high C coil, if you had to use magnet wire, keep it to .2 mm max. Generally, 7 strand x .2 mm tinned copper wire with teflon or similar will give good results without any spacing, the insulation gives that.
The biggest issue with flat coils is the extra turns needed to achieve the required inductance will tends to make the flat wound heavier and larger than same sized bundle, you have to experiment.
I have included a photo of my concentric construction for some ideas.
Just my two bobs worth anyway





cheers

Mdtoday