hi

did you know this?

https://www.youtube.com/watch?v=P-GUMANrUSA

73 muhsin TA1MHS

I've done it that way for years.  Old crochet hooks are handy.

The plastic ones are best and you can get different sizes for
differing cores or wire diameters.


Allison
------------------
Post online only, please no email.

Muhsin,

I've been winding toroids with a crochet hook for the last 25 years.  The only way to do it if you want the windings tight to the core.

Thanks for your post and 72/73,

Jim, K8IQY

Thanks for this tip about winding toroids.  I was unaware of it.

Is there any disadvantage to having the windings tight on the core?
Does the core scratch the wire insulation as a turn is being snugged up?
Do you lose too much of the slack needed to do spacing adjustments when tuning a filter?
Do I worry too much????

Gotta go get me some crochet hooks!

Thanks for this tip about winding toroids.  I was unaware of it.

Most people are.

Is there any disadvantage to having the windings tight on the core?

No, actually better, as the inductance is more consistent.

Does the core scratch the wire insulation as a turn is being snugged up?

No, as the turn will go on snugged.

Do you lose too much of the slack needed to do spacing adjustments when tuning a filter?

No, you can still more the turns around.

Do I worry too much????

Maybe.....

Gotta go get me some crochet hooks!

Size E or #2, in plastic (preferred), or anodized aluminum if plastic isn't available.

72/73 and have fun,

Jim, K8IQY

HINT:
Painted cores (powdered iron) like T37-2 (red) or T37-6(yellow) are smooth.

Ferrite cores (ceramic) FTxx-xx have hard edges and can scrape the wire.
Easy solution is coat it or get them as tumbled (removes the edges).

--
Allison
------------------
Post online only, please no email.

I'd caution against tumbling as it would remove material from the toroid everywhere not just "soften" any hard edges and thus changing the inductance specs.

I've only encountered hard edges on binocular cores not toroids which have pretty consistent radiusing on the edges.

Also don't assume that what you see is a monolithic medium, in some cases it may be a more complex sintered core with a specific glaze on it. Modifying it without really understanding what it is wouldn't be a good idea and could cause a breakdown in its intended function. 

My 2€!

 

Rich,

For the low-pass filter (LPF) toroids, a teeny bit of slack is useful
for when you need to tweak the inductance to tune the filters.

I knew the trick of coating cores with rough edges. I'm not sure
whether I'd tumble toroids, because it removes material and hence
reduces inductance -- probably guaranteeing the need for tuning. But
on the bright side, the toroid will be smoother and easier to move the
windings. :).

Nevertheless, since the characteristics of toroid core material vary
significantly from batch to batch, it may be a moot point and I'll
just settle for using clear spray paint.

As for the crochet hook trick, that's very new to me, and counts as my
Best New Idea Of The Week. I think I know where my late mother's
crochet hooks ended up (no crotchety old lady jokes, please) so I'll
give this a try.

73
Jim N6OTQ

On 27 Nov 2022 at 10:54, Jim Kortge wrote:

Size E or #2, in plastic (preferred), or anodized aluminum if
plastic isn't available.

or maybe cut a hook in the end of a chopstick?

w2jc

Or ... bend some bamboo?

If you have access to some reasonably fresh bamboo, you can bend it by
heating it gently in a clean (non-sooting) flame like your gas stove
or a propane torch. It's really surprising to see.

If you bend it and then whittle it down, it'll be a lot stronger than
just carving a notch.

73
Jim N6OTQ

This has been very interesting.  I have a 3mm anodized hook on order from the A place. 
I am assuming the toroid would be GENTLY placed in a vice, and eventually rotated, exposing new surface. This was in the original video (thanks again!)  The vice alone (GENTLY) is helpful. 
73 Bruce 

On 27 Nov 2022 at 14:39, Bruce wrote:

I am assuming the toroid would be GENTLY placed in a
vice, and eventually rotated,

maybe stick some padding/foam to the vice jaws
for tenderness...

w2jc

I thought I was a fairly experienced builder, but I have never tried this!  A soon as I saw the video, I ran out to the local Joann's and bought a couple of different sizes.  I'm actually excited about the next couple of kit builds.
Thank you so much for the tip!
--
Brent DeWitt, AB1LF
Milford, MA

On 11/27/22 17:46, Jim W2JC wrote:

On 27 Nov 2022 at 14:39, Bruce wrote:

I am assuming the toroid would be GENTLY placed in a
vice, and eventually rotated,

maybe stick some padding/foam to the vice jaws
for tenderness...

The 3D print web site thingiverse.com has toroid vices (search for toroid). I haven't
printed one but after having trouble holding L12 at the start I am considering it. :-)

I should probably break out the chopstick and see if that can hold it in place while
I knit the wire through.

--
Linux Home Automation Neil Cherry kd2zrq@...
http://www.linuxha.com/ Main site
http://linuxha.blogspot.com/ My HA Blog
Author of: Linux Smart Homes For Dummies KD2ZRQ

Hi Bruce,

I’ve used cone shaped knitting dowels but this approach sure seems quicker. There are small vices in the hobby space that have plastic or resin jaw covers. They seem like a good approach to handle a brittle ferrite toroid.

73,

Frank
K4FMH

Re/ vice padding, I have been thinking about trying pieces of leather. But "tenderness" is the key.
And I need to strongly suggest to everyone that practice, on some toroids you can afford to loose, is in order here, before you crack or break something you have precious few of! YMMV and Hans provides good basic guidance on how to wind, tried and true. 
73 ~ Bruce K3BAB 

I took a 3/8” wood dowel,  it about 3” off put it in my drill press and put a taper on it from about 3/16 to 3/8 with a file.

On 11/27/22 21:35, KK4ITX John via groups.io wrote:

I took a 3/8” wood dowel,  it about 3” off put it in my drill press and put a taper on it from about 3/16 to 3/8 with a file.
I then put a slot from the point on down deeper enough for a 22ga wire to pass through.
Finally I flatten opposite sides enough so that the drill vise could secure it.
Simply feed the wire through the slot, press it by pulling down on the toroid and repeat turning so the next turn of wire can pass through.
The result is easy winding and if interrupted just “set” the toroid down on the dowel to hold everything in place.
Really works good on the small critters !
John
KK4ITX

+1

Cool found some spare chopsticks!
I can cut them up anyway I want. I'll drill a 2x4 and try using that as a base.

--
Linux Home Automation Neil Cherry kd2zrq@...
http://www.linuxha.com/ Main site
http://linuxha.blogspot.com/ My HA Blog
Author of: Linux Smart Homes For Dummies KD2ZRQ

Just wrap the core with plumbers tape for padding. It thins as you stretch it so should not affect the inductance.

Dave K8WPE

David J. Wilcox’s iPad

Specifically, common white Teflon tape?  Other plumber's tapes can be very thick (for gas lines, etc.)