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Registered Member #955
Joined: Wed Aug 15 2007, 04:28AM
Location:
Posts: 9
GreySoul wrote ...
$1300 sounds like you need to seriously reconsider the value of your labor. ...
The pipe and wire MIGHT be worth $20 to someone if they needed the pipe OR the wire, and were going to toss the other. Your labor isn't of any value in that case.
The copper is probably worth $5-6 to a recycler.
As 5 smaller coils it may be worth $50-80 each, but the ebay market is already saturated with 6" pre-wound coils. that already includes the labor.
The ellipsoid topload is worth maybe $10 - it's clearly 2 bowls attached to each other... or is it something else? in any case, a toroid would be preferable. Again, labor might be worth an extra $5-10 to someone... but a nice spun aluminum toroid is where people with money go for their top loads.
The base is really not all that impressive. It looks decently well built, and I apologize for my dissing on it';s construction... but it's worth maybe $50 in wood and part, and .... maybe took an hour or two to build.... I'd say maybe get $75 for it, if someone wants to buy rather than build.
the primary coil is only worth somethign if it's tuned to the coil you're selling... and even then it's worth maybe $20.
The Neon Sign Transformer, at 10.5KV and not knowing it's design or power rating it close to worthless.
if it's a 90ma old style NST you can probably get $40-60 at a hamfest if it's in good shape, maybe a little more on ebay if you get the right day and buyer.
If it's a brand new iron core NST it's worth a bit more...
If it's a high frequency modern NST with circuit protection built in it's worthless for coil use.
Whatever capacitor you have is not clear - if it's a beer bottle cap it's hard to value - the beer inside is gone....And you can't really demand payment for drinking the beer....Still, I'd probably pay $100 for a well built working bottle cap demo unit (no, I don't need one, thanks everyone)
if it's a well built MMC then it could be worth $100-200 or maybe more if it's a large well made MMC.
...so honestly, since you seem a little more legitimate than the average fly-by-night scammer... you've come back, that says a lot to me...
Why do you think that coil is worth so much, or why are you asking so much if you know it's not?
-Doug
6 inch dia 13 foot pvc pipe: $50 10 lb roll of 28 AWG magnet wire: $50 Can of Varnish: $10 Labor: $150-$200
Registered Member #955
Joined: Wed Aug 15 2007, 04:28AM
Location:
Posts: 9
NeilThomas wrote ...
Well, you have to admire his balls for showing up.
Hi Mwahahaha, a couple of questions, as I'm intrigued.
Given that you obviously picked up enough info (from the net presumably) to know about the components, how come you settled on the 12ft x 6inch design for the secondary, when a little more digging on any reputable source, Pupman, here, or using any sort of TC calculator, gives an aspect ratio of like 4 (+/-1) :1 and around 1000 turns as being a good place to start?
Why give up now after all that effort? If you are short of good caps, then beer bottle caps are free and will get you going (OK, drinking all that beer is a tedious rotten job, but somebody has to do it!)
If your only crime is devoting money and building time before having done enough homework, then hey, we're all been sinners at some time, me particularly. Stick around, ask some questions. Maybe buy some 942s, maybe empty some bottles. Cut the secondary into several pieces, unwind one back to 24" and sell the others (there's no way anybody will buy 12ft, but they might buy a 3ft ready wound secondary, even if the wire is a bit thinner and the number of turns a bit higher than ideal). You may get your TC going after all.
<preach> Show an ability to learn and I've no doubt that the laughter will stop. This is a great forum for rational members who do their homework </preach>
I decided on the 6" dia 13 foot coil because i wanted to make the largest possible coil and the largest roll of magnet wire i could find was ten lbs. Any smaller than 28 Awg and it would break to easily. and any larger and i would require more than 10 lbs to coat the pipe. I thought about using an 8 inch diameter 13 foot pipe, but i couldn't find enough wire to coat it. As for the caps some are leyden jars made from mayonaise jars, the other is made from sheets of aluminum stacked between plates of 1/4 inch glass.
do you know where i can find a good resonant frequency equation for primary and secondary circuits.
Ahh-ha-ha-ha-haaaaAAAAAAAA!!! Ok, now this has to be about the worst/funniest/most pathetic example of an eBay Tesla coil sale I have EVER SEEN! It's quite clear the builder (probably the seller) had no idea what he was doing when he built it. My favorite parts are too numerous to list, but here are a few of them: * The fact that the condition is listed as "new". * The hideous 24:1 aspect ratio of the secondary. * The primary and base, which look like souped-up versions of everybody's hackiest, most hastily thrown-together shop projects <shrug> ... but I'd never try selling my hackiest, most hastily thrown-together shop projects! * The claim of 20' "arcs of lightning". Yeah...maybe if it tips into some overhead power lines! * And last but not least: "I will sell the stand, the secondary coil, and a 10,500 volt neon sign transformer for $4,700"
Well...I don't know what more to say.
EDIT: Oh wait! I forgot:
* The topload that looks like a metalized shrimp pot buoy.
Cheers, Aaron, N7OE
when i put that coil on ebay i didn't really expect it to sell, but i've got to say i'm surprised that there was a forum thread created to make fun of it.
Registered Member #546
Joined: Fri Feb 23 2007, 11:43PM
Location: Albuquerque, NM
Posts: 239
Ok, first read the forum rules: NO double posting, let alone quintuple posting....
Second, what you paid for new materials and what they're worth after you've purposed them are two differnt things. I'm sorry you're getting the short end on this one, but consider it a lesson learned.
FWIW, I could wind a 12' coil in about an hour, and that includes setting up the lathe for a 12 foot bed.... I don't think your winding labor is worth $200/hr. manually wound coils are not a commercially viable product and shouldn't be sold as "new" unless they're completely flawless ... that's just my opinions, others may feel other ways.
I'm glad you didn't waste your time on an 8" coil.... 8" pipe isn't cheap.
...
And why did you bother to wind a coil without knowing anything about the theory behind them? A cursory search of google for "tesla coil calculators" should result in plenty of information. the 4hv wiki would also be a good place to start.
And why pay to list an itom on ebay if you don't plan to sell it?
... I dunno guy, seems like you're way ahead of yourself ... slow down and read up first. This is a great place to start.
a 24" x 4" coil could actually be useful....depending on the number of turns.
Registered Member #72
Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659
Some of what you say has an element of reason behind it, but with only half the story you're coming to the wrong conclusion.
so ... if a transformer secondary produces x volts per turn, then you get a higher output voltage with more turns? Right? so more turns is more volts? right? Yes, if it's conventional transformer, that is strongly coupled and non-resonaant. Unfortunately, the Tesla coil is double tuned weakly coupled resonant system, and it has to be designed as a system. All parameters are significant, but Q is possibly one of the most so, and this needs few turns of thick wire. Whatever the size of the coil (disruptive spark), it seems that the best performance, in terms of best streamer length, is given when the number of turns is in the 1000 ballpark, though 800-1600 are not uncommon.
Doing what you've done is not a crime, but continuing to do it, once you've had the error of your ways pointed out, is. Enter the 12 step program. Say, "my name is Mwahahaha, and I don't fully understand the design principles of Tesla coils". I didn't understand once, to be honest I'm not sure I completely understand all the subtleties now. But I do know I need to learn.
I get off most on seeing people understand new things. Go on, do you and me a favour by waking up, recognising well meant criticism and guidance, and attempt to learn some more.
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
This thread failed completely to stay on topic so it is closed.
In addition Mwahahaha managed to set an unbeatable record by posting 6 times in a row and advertising items for sale even if he does not have the required number of posts.
If anyone has something sensible and important to say or ask they can start a new on topic thread.
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12ft Tesla coil: Get yours NOW!!
