High Voltage Forum
General Chat => General Chat => Topic started by: TDAF on May 01, 2018, 07:22:34 AM
-
My question is how should one go about making End-caps for a 10 inch diameter secondary coil
what are the materials good for this??
-
I use a router that is just modified with a pivot on a rod. Scrol down to "10th October 2009" on http://kaizerpowerelectronics.dk/tesla-coils/kaizer-drsstc-i/ and you can see how it was made with a normal router and that we used it to cut the round base plates for the DRSSTC1.
Anything non-conductive, hard plastic types. If you are looking for cheap alternatives, look at IKEA bread boards or something like large nylon meat cutting boards for professional kitchens.
-
will something like acrylic sheets work??
-
will something like acrylic sheets work??
It is too brittle to withstand the stress of holding the secondary in place if you were to bump into it.
-
would "casting" epoxy end-caps into the secondary be an option? Or maybe cut some plywood discs and glue/polyurethane in place as a cheaper alternative.
-
would "casting" epoxy end-caps into the secondary be an option? Or maybe cut some plywood discs and glue/polyurethane in place as a cheaper alternative.
Plywood with a good amount of epoxy/polyurethane would properly be just as fine as many other solutions. But I would not use a bare wood disc due to higher risk of carbon tracking.
-
Check out how I did it using cheap polyester resin for my 160 mm DRSSTC secondary
https://highvoltageforum.net/index.php?topic=78.msg349#msg349
-
For my 200mm secondary, I used wooden disc at the ends and 4 3d printed disc of PLA in the tube
-
I was lazy and just used the plumbing store end-caps for the PVC tube. Doesn't look quite as good, but they fit tight enough to allow them to secure the bottom of the secondary coil, while being easy to assemble/disassemble (I bolted the cap to the primary support with nylon bolts, and the base of the coil fits into the cap and is held by friction). I also used nylon bolts for holding on the topload (end-cap glued on this time), 3 for my 160mm coil, 1 for my 110mm coil.
-
In my old days and for bigger secondaries I only used a cap on the top of the coil.
For this I made an insert and glued a thin sheet on top of it.
The insert was pushed into the tube to produce a "pot" about 5mm deep and then filled with resin.
Usually the mounting screw for the topload was placed in before and wired up.
The bottom did not get a cover but instead an insert on the base.
Top of the that insert was slightly conical to make it easier to get the primary on it.
Depending on the height and how thight this insert was I used 5 to 10 cm in lenght here.
Just means you need to keep that base mount in mind when designing and winding.
Also noticed that it pays off to have this bottom mount adjustable in height for various reasons.
-
The problem is that I am not able to find the push pvc caps in my locality
Only ones available are ones which mate with a collar first :-[
-
Ahhh, I feel your pain.
Had to go to a dedicated plumbing store for mine.
But if you have some left overs, an oven and something to cut PVC with...
Cut pieces of your pipe off that are longer than the diameter.
Cut these pieces with a hacksaw lenghtwise.
With a flat sheet or tray in the oven and preferably a sheet of non stick baking paper you can now heat the cut pipe sections.
A temp of 180 - 200°C should suffice to get the PVC soft enough.
First try to make them unroll.
Then move and turn them until the pipe looks like a flat sheet, more or less at least.
Take them out while still soft and use a dough roller, bottle or similar to really flatten them on a wooden board.
Once cooled and hard cut a disk out to fit tightly into your pipe.
(does not need to be perfect)
Use standard PVC glue and primer as directed on the packs to glue the disks into place.
First one is the hardest, so here is how to cheat:
As you should have a rig for the winding, use it ;)
Place the first dis inside and align it so if you spin the pipe it won't wobble.
Using a brush apply some primer along the joint area, don't soak it though.
Add a bit of glue in tree or four points, only a little bit!
While slowly spinning spread the glue to a really thin layer - it will dry quick...
Make sure the disk won't wobble and let this first bit of glue set.
The second disk will be inserted dry after applying a thicker coat of glue to the disk inside, cover the entire surface as thin as possible but thick enough to fill imperfections.
Push the second disk in and use a rounded pin or similar to push it against the first disk while all is spinning slowly.
You should see a small amount of glue coming out the joint area, wipe it off or spread it out.
Once all is set you can fill the remaining gap with resin for added stability.
A quicker way to cheat is to use a wooden disk.
Cut and sand it for a an easy fit, so leave a gap big enough so you could wrap a single layer of paper around the disk.
Use Chloroprene cement, also named shoe glue, neoprene glue, to make the connection.
Brush the joint area on the wood with some acetone, you want a slight wet look without soaking the wood.
Before it dries apply a coat of the glue and spread it evenly to get full coverage of the wooden joint area.
Prepare the PVC by wiping PVC primer over the joint area.
Before either fully dries press the disk into your pipe.
You only have limited time for adjustments and I find it beneficial to just place the disk on a non stick surface and then to slide the pipe over.
For bigger ones secure the disk with a screw for added stability but please through whatever it rests on into the bottom and not from the top as you need a bloody long screwdriver to get it out ;)