Threaded rods in secondaries.
Duncan, Sat Feb 17 2007, 05:31AMHi All,
Just a query, I've seen a lot of people use threaded rods in their secondaries to make toroid and ground connections easy and secure, but was wondering exactly how the threaded rods are mounted to the ends of the secondary. It is my understanding that no metal should go inside the secondary form, so how do you attach the threaded rods securely?
Re: Threaded rods in secondaries.
Marko, Sat Feb 17 2007, 11:39AM
Well, most of us seem ot use metal nuts. 2-3cm ofmetal inside the secondary doesn't seem to be a problem.
I use brass as much as I can but people also seem to use steel for their toroid connection without problems.
Marko, Sat Feb 17 2007, 11:39AM
It is my understanding that no metal should go inside the secondary form, so how do you attach the threaded rods securely?
Well, most of us seem ot use metal nuts. 2-3cm ofmetal inside the secondary doesn't seem to be a problem.
I use brass as much as I can but people also seem to use steel for their toroid connection without problems.
Re: Threaded rods in secondaries.
Duncan, Sat Feb 17 2007, 12:58PM
Ah great. I was planning on using a brass threaded rod. There's no chance of any streamers breaking out from the end of the brass rod that's inside the secondary form is there?
Duncan, Sat Feb 17 2007, 12:58PM
Ah great. I was planning on using a brass threaded rod. There's no chance of any streamers breaking out from the end of the brass rod that's inside the secondary form is there?
Re: Threaded rods in secondaries.
Marko, Sat Feb 17 2007, 01:20PM
I don't remember if such a thing ever happened. Voltage difference is way too low for this, unless your screw goes down by third of secondary or so. Secondary is much more likely to flash over it's windings or from racing sparks.
In most cases I anyway have space for caps on the ends so my screws aren't actually even 'inside' the winding.
I usually run my wire through a small hole into the secondary for better physical rigidity, although some advise against it (I once had the wire disconnect, fall down and set my secondary on fire while I was unable to see it).
Marko, Sat Feb 17 2007, 01:20PM
I don't remember if such a thing ever happened. Voltage difference is way too low for this, unless your screw goes down by third of secondary or so. Secondary is much more likely to flash over it's windings or from racing sparks.
In most cases I anyway have space for caps on the ends so my screws aren't actually even 'inside' the winding.
I usually run my wire through a small hole into the secondary for better physical rigidity, although some advise against it (I once had the wire disconnect, fall down and set my secondary on fire while I was unable to see it).
Re: Threaded rods in secondaries.
Hazmatt_(The Underdog), Sun Feb 18 2007, 01:06AM
if you're pushing out arc's less then 2x the winding length its no big deal to use metal hardware on the coil form. However, I was pushing some arcs that were pretty long and I was sure there was arcing racing down the inside. What I used to do is use some copper tape wrapped around the bottom lip of the coil form to make my ground connection, but this was a source of my problems. What I am doing now is using PVC cement to affix a copper pad to the PVC pipe and it stays pretty well. I have some nylon hardware that comes through the back to the front with some knurled nuts to hold forked terminals to the copper pad, and it looks pretty decent. I would have a photo of it, but the coil is still at college overdue for a rewind and makeover almost a year later. I'll post some photos of the thing when it comes back home though.
Hazmatt_(The Underdog), Sun Feb 18 2007, 01:06AM
if you're pushing out arc's less then 2x the winding length its no big deal to use metal hardware on the coil form. However, I was pushing some arcs that were pretty long and I was sure there was arcing racing down the inside. What I used to do is use some copper tape wrapped around the bottom lip of the coil form to make my ground connection, but this was a source of my problems. What I am doing now is using PVC cement to affix a copper pad to the PVC pipe and it stays pretty well. I have some nylon hardware that comes through the back to the front with some knurled nuts to hold forked terminals to the copper pad, and it looks pretty decent. I would have a photo of it, but the coil is still at college overdue for a rewind and makeover almost a year later. I'll post some photos of the thing when it comes back home though.
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