Bob Boyce TPU thread

[Bob Boyce]

I'm glad to know that as well. Of course, they will probably try to outlaw beeswax when they find out it is being used for coil winding once again. Just like the Consumer Product Safety Commission has tried to eliminate non-blended sodium hydroxide drain cleaners from store shelves here in the US.

Well, the last longitudinal winding is finally finished. I turned a short piece of 3" ABS pipe down on my lathe and used that as a preform to make winding the inside hole a bit easier. I wrapped the 48 turns onto the preform, then smeared them with beeswax before transferring them over to the core one turn at a time.

Bob

[Bruce_TPU]

Well, the last longitudinal winding is finally finished. I turned a short piece of 3" ABS pipe down on my lathe and used that as a preform to make winding the inside hole a bit easier. I wrapped the 48 turns onto the preform, then smeared them with beeswax before transferring them over to the core one turn at a time.

Bob

Hi Bob,

It is easy to see that you have wound a few coils in your day!  I do have two questions.

With the first winding, for the magnetic bias, do you smear bee's wax first over the surface of the toroid, and then simply wind on top of that?

And what is the yellow paper like stuff you have waxed, glued on top of everything?  It does not look like electrical tape.  Would electrical tape work, or would you recommend this yellow stuff?

Bruce

[Bob Boyce]

Hi Bob,

It is easy to see that you have wound a few coils in your day!  I do have two questions.

With the first winding, for the magnetic bias, do you smear bee's wax first over the surface of the toroid, and then simply wind on top of that?

And what is the yellow paper like stuff you have waxed, glued on top of everything?  It does not look like electrical tape.  Would electrical tape work, or would you recommend this yellow stuff?

Bruce

I rub cold beeswax over the core surface first to make it just a bit tacky. Then as I wind, I rub wax into the windings by hand to secure those windings. I work this wax with my fingers to soften it as I wind. After I finish, I rub in a good dose of wax to seal the windings well. Beeswax makes an excellent inert potting to hold the windings in place until they can be securely wrapped with winding tape.

Which brings us to the winding tape. It is very strong and thin, and has almost no stretch to it. It is available in many colors and widths. Some has adhesive and some does not, I have both types. PVC electrical tape will work, but it stretches, especially when it warms up, so it provides very little in the way of support for the windings. Winding tape can be obtained from suppliers that carry electric motor and transformer rewind supplies.

In the late 70s I had the opportunity to train in electric motor/transformer rewind. I then worked in a motor/transformer rewind shop for a short time. This experience helped me greatly. Back then we used wax and waxed chord to tie windings up. We then heated and dipped them in varnish, while exposed to vacuum to draw out air and excess wax, then allowed atmospheric pressure to push the varnish in. Then we would bake the windings to set the varnish.

One thing I learned from that is to make darned sure that all underwinding leads are covered with good dielectric strength woven fiberglass sleeving. This can add a good 5KV or more of dielectric strength to the flying leads of magnet wire windings. I will be adding this to my longitudinal winding leads prior to winding my secondary.

Bob

[Bob Boyce]

Taped up and awaiting the woven fiberglass sleeving prior to winding the secondary.

Bob

[Bruce_TPU]

Hi Bob,

Great information as always.  We look forward to seeing and learning more of the fiberglass sleeve.  This is indeed feeling like we are winding a generator.

If you test your new longitudal windings on top, bottom and inside core, and it indeed gives output, we will add these windings to ours as well and I will add those photo's to the page 2 photo journal

@ Everyone

Page 1 Build page is active.  Need sources for the winding tape and I will add it.  Please check it out.  Also Page 2 is a Photo Journal for easy viewing all in one place, when our cores arrive.

Bruce