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New small 4 inch sgtc.

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Arcstarter

Fri Jan 02 2009, 12:42AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

Well, i did it on a cold night, and it is cold right now.

I currently have 4 layers of varnish, and it is looking pretty nice. No other updates for now.

Hazmatt_(The Underdog)

Fri Jan 02 2009, 01:00AM

Registered Member #135 Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735

Good, you won't have to worry then.

I usually run out of time during the construction process so I have to varnish days later, and then its all a mess >.<.

Arcstarter

Fri Jan 02 2009, 04:44AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

Hazmatt_(The Underdog) wrote ...

Good, you won't have to worry then.

I usually run out of time during the construction process so I have to varnish days later, and then its all a mess >.<.

I know the feeling. One time i made a secondary(the one i have been using for like a year!!) and from start to finish was about a month or two, which was about 1 year ago, and i STILL haven't varnished! It had a bunch of overlapping on the bottom, and i am sure elsewhere also which are still there. Also, the six inch coil i started winding was half wound i think two days before the storm, and when i got back from the storm it was screwed. Used the rest of the wire that was not used for the new one.

The new one looks good, i can run my fingernails across and you can barely feel the bumps of the wires. A few more coats and i will very lightly;y sand, then many more coats.

Arcstarter

Thu Jan 08 2009, 05:52PM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

I have made little progress on the coil. The only thing i have received for the coil since last time (the tank caps) is the doubler capacitor bleeders.

The worst part is the secondary. It look horrible now. Even though it had 5 coatings on it, i think some of the wire was lifting up and trying to overlap. There are air bubble. I am not sure what caused them, but it was only one coat that had the air bubbles. It is pretty sad to see all this work turn out to look so bad.

Ok, i just went and looked and the wire looks pretty much PERFECT other than the places where there where gaps! YAY! Anyway, the polyurethane is bumpy, but that does not matter. After a few more coats i will sand it until looks good, and then put more coatings, as i want more protection from scratched/insulation, and after sanding it will look bad because there will be scratches that will need to be filled in. Also, there where bubbles on one of the previous coatings, so that kinda shows. I am not too worried about look, compared to functionality.

I took a picture of the end of it, which is the worst part, so you can see what i mean.

EDIT: i have put i think 3 more coats on today, and it looks much better. It is very flat and stuff like that. Tomorrow i will take a video of me coating it to show progress, and then i will sand it to get it completely flat, and then put i guess 8 more coats. I currently have 12, and it is spinning right now.

Yesterday (IIRC) i took the driver apart and oiled the reduction gear assembly. I soaked the slower parts with thick gear oil, and the motor, and first stage of reduction gears with some thinner oil. I also oiled the metal rod with the gear oil where it is held up by the wood. This all may sound unnecessary, but the driver is not made for such extender runs, so the oil either wont last long, or the gears will start to get eaten up. And, the oiling of the rod/wood really helped.

Today i have been thinking really well, so i came up with an idea for a RSG disk. I cannot explain it good, so i will just wait until i am done with it and show you the pictures. Pictures are worth 1000 words! Oh, and the RSG disk should be done by tonight. I will probably still use the vacuum cleaner motor running at low voltage with a PWM speed controller using a 555 oscillator and some mosfets or IGBT's. Or maybe even my small BJTs since it will be low current and voltage.

Still waiting for the doubler caps and diodes(which will also serve as the De-Qing diode) to arrive. When they do, i can but it all together.

Oh, and just so you know, the next SGTC i am doing after this(this is in the far future), may be the same type, but two MOTs and a doubler, with about 40-60nf of tank capacitance, and a 6 inch coil form, with like 22 or 20 gauge wire.

Arcstarter

Tue Jan 13 2009, 05:42AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

Hello there.

Today my doubler capacitors AND diodes came. I had the doubler cap bleeder resistors for awhile now.

I started on the capacitors. Remember, there are 4 different capacitors. Two of them consist of 7 capacitors, and 2 consist of 14 capacitors.

I cut the PC board with an unusual tool. I used an angle grinder with a cut-off wheel, made for metal. Regardless of the two materials being much different, it cut cleanly with no cracking, chipping, and no 'catching'.

I made one capacitor, the 1.5uf 6kv one, made of 14 22uf 400vdc(supposed to be 450 volts according to Steve Conner but this will suffice, i suppose). I also soldered the bleeder resistors onto it, as you could imagine. It was of course made on one of the four pieces of PC board that i cut. I calculated that there was 98 solders on the board that i just made. There was seven solder joints per capacitor. Two to hold the capacitor onto the board, two to hold the resistor to the board, two to solder the resistor to the capacitor leads, and one to connect that capacitor to the next. And there are 14 capacitors, so 7x14 is 98.

The board of capacitors and resistors is very messy. It looks bad, but if the board didn't break, i could throw this as hard as i could and it would not break. Maybe.

Here are some pictures.

#1 is the top of the capacitor board.
#2 is the very messy bottom.
#3 is the four pieces of PC board i cut.
#4 is the capacitors and diodes, in there packages when they arrived.

Edit: I forgot to say some stuff. The secondary had to be taken out of the room i was winding it in. It is currently sitting in the shed. I do not trust the shed though, if the dorr pop open, it could get wet or dirty. And the doors do not stay shut..

The coil has 13 heavy coats. Looks alright, but needs to be sanded and then i need to put some more coats on it.

I have no money for copper pipe for a primary. This project might have to wait until may when i can get the money, for my birthday. I will mow lawns when they start growing again, but that is not the near future.

I am going to hook everything up with wire. I have some very thick wire, about 1/4 inch thick, if not thicker. I will make some crimps out of steel strapping, by heating them up with a torch and bending. I will put the mire inside and beat it until it grabs the wire hard enough. Then, i will find some way to attach that to the capacitor leads. I guess cut a few small holes and but the lead through that, and then solder.

I have some 555's coming, and when i get those i will make the PWM rsg speed controller. I have made the RSG disk and put it on the vacuum cleaner motor and spun it up pretty fast and nothing bad happened. I will be using 12 volts. It will be supplied from a small transformer i suppose. I still need to make the static electrodes on the RSG, so that will be done here at some point.

I started soldering the capacitor bank together about a week ago, but i must finish it up. I have a few done, about 5 of 12. The joints i have done so far look horrible because the soldering iron will just not heat them up enough.

I need to get some HV wire to hook up the MOT and doubler, and some more battery/amp cable to wire the high current stuff. I have a very large clamp i would like to use from a jumper cable, but it is too big and the sparks would strike it and burn primary components.

I also need to get a variac, but they are expensive and i don't have the money. That can wait though, i need to buy the copper tubing first.

YAY long posts! If you read this far, GOOD JOB!

aonomus

Tue Jan 13 2009, 05:56AM

Registered Member #1497 Joined: Thu May 22 2008, 05:24AM
Location: Toronto, Ontario, Canada
Posts: 801

You can typically make clean cuts by scoring perf boards repeatedly with a sharp utility knife on both sides, then using the edge of a solid desk to snap it at the scored point, similar to cutting acrylic plastic.

Arcstarter

Tue Jan 13 2009, 06:09AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

aonomus wrote ...

You can typically make clean cuts by scoring perf boards repeatedly with a sharp utility knife on both sides, then using the edge of a solid desk to snap it at the scored point, similar to cutting acrylic plastic.

....
I was thinking about scoring it, but i figured that would never work.

Hmmmbleh.

Arcstarter

Sun Apr 05 2009, 03:36AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

I FINALLY decided to put it all together. I am currently running very high bps (i am almost certain it is 1000bps or so) with a high speed universal motor and 8 flying electrodes. The rsg sucks though, i am going to remake it. The whole thing uses quite a bit under 15 amps. The power MOT, the rsg power, and all of the kitchen (at the time the fridge was running along with the 4 florescent lights) and the breaker is 15 amps.

The sparks are only about 2 feet, but i have not even began to tune yet. I need to make the new topload and rsg also. I will be making a PWM motor controller. I have made one before, and it went from not spinning to about 95%. The rsg is still only running about 70-80 volts, but i am not sure if the full speed will be good for the (thick) plywood disk XD.

Anyway, video (and dont laugh about the toilet, we just got the other half of our houses ceilings and walls back XD):

Arcstarter

Sun Apr 12 2009, 01:07AM

Registered Member #1225 Joined: Sat Jan 12 2008, 01:24AM
Location: Beaumont, Texas, USA
Posts: 2253

I made a new base for the coil to be a bit more portable. All i did was add legs and a piece of plywood for the transformers and all of that to sit on.

Overview.

Bottom closeup.
Looks pretty bad, but it gets the job done..

But i took it outside to run it today, and it can be described as less than successful. The charging chokes failed, and i added TWO MORE in series, but they where shorted beforehand. I also need to make the whole power supply on a piece of THICK plastic, as wood does short quite often. I also need some THICK plastic for the RSG, as wood shorts....

If someone knows where i could find a good choke that could withstand 10-20kv (it does not have to be MADE for this voltage, it just has to be able to handle it XD) and around 30 or 40 henries. Of course i don't have money, so the cheaper the better.

Also, if someone has some spare plexi or other strong resilient plastic that are just scraps, i will buy it. Depends on price XD

EDIT: Forgot to say stuff...

When i started running it, it would work normally for half a second or less, and then the rsg would have a hot flame go around the wheel. This was of course the chokes arcing, letting the full power of the MOT go into the rsg, instead of the cap bank.

It pulled a ton more current than last time. Enough to trip a 13 amp break in a few seconds at lower bps!! This is because of those STUPID chokes (MOTs, call it what you want). Before it probably pulled 8 amps all together.

I used a light dimmer as the rsg power source. This worked great. It needs some shielding though, at higher BPS the rsg motor started varying automatically!! I ran the thing at full speed, YAY! MAN WAS THAT A LOUD AND ANNOYING SOUND!!!! The sparks where about a foot and a half at this BPS, and it SERIOUSLY looked just like a CW sstc spark! it was pretty crazy, and it broke out in one preferred spot on the toroid at this BPS, which started to really heat! I estimate around 1500bps, the motor is i think 20krpm (i was running full speed) and i have 8 electrodes. That would be 2666bps, but the rsg did slow down about 2 times the original speed when i turned the power mot on. It did however sound like it could have easily been 2khz (2BPS).

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