Community rules
CommonGnd is a science-based forum for high-voltage builders, from someone's very first spark to record-breaking arcs. Two things run through everything here: evidence over opinion, and safety above all. We help each other, we're kind to beginners, and we keep it honest.
New here? Read these once, then come and introduce yourself in Start Here and ask your first question in Beginners. The rules are deliberately short and human. They exist to keep the place safe and useful, not to trip you up.
How we treat each other
Respect: talk like people in a workshop
We're all here because we love the same dangerous, beautiful thing. Criticise the work, not the person: "your grounding scheme will cause racing sparks, here's why" is welcome; "you're an idiot" is not. Mocking beginners for asking a basic question is never allowed; everyone wound their first secondary badly. Assume good faith and give people the benefit of the doubt before you sharpen a reply.
Let the moderators moderate
If you're not a moderator, don't act like one. Don't greet new members by accusing them of not reading the rules, and don't pile on or make people feel unwelcome. If a post is a genuine problem, use the flag button and let a moderator handle it. That's what they're for. Being hostile "in defence of the rules" is itself against the rules.
Asking and posting well
This is a place to learn and to help. A good question gets good answers; a lazy one wastes everyone's time.
Do your own research first
Before you ask, search the forum and the canon. Your question has often been answered already. Don't ask for complete schematics, detailed plans or step-by-step build instructions; ask specific questions that show you've done the reading. A good post says what you're building, what isn't working, what you've already tried and measured, and includes a photo or schematic. "It doesn't work, send me a full DRSSTC design" gets nowhere; "my UD2.7 half-bridge shoot-throughs at 30 kHz, scope shots attached, here's my gate drive" gets help fast.
Evidence, not opinion: no pseudoscience
This is a science-based technical forum. Hard evidence, measurements and reproducible test results drive discussion, not politics, marketing or personal belief. Free energy, over-unity, perpetual motion, electrogravitics and other pseudoscience are not allowed anywhere on the site, and neither are links to sites that primarily push them. If you genuinely believe you have an exception, you'd better arrive with undeniable, reproducible, independently-checkable proof. Extraordinary claims need extraordinary evidence.
Stay on topic, and don't double-post
Keep threads about the thing they're about; off-topic chatter goes in Chat and trading goes in the Marketplace. Double-posting (replying to your own thread twice in a row with no answers in between, just to bump it back to the top) is not allowed. Every topic gets its chance; if it slips down the list, that's how it goes. If more than 48 hours have passed and you have genuinely new information to add, one follow-up is fine. Posting the same question in two separate threads counts as double-posting too.
Safety
Safety comes before everything
Tesla coils run at lethal voltages, and the danger isn't just the topload. It's the supply, the primary and the capacitors that stay charged after power-off. Any advice that could hurt someone must carry a warning in the same breath; dangerous instructions posted without safety context are removed. Reading the safety guide is part of joining, not an optional extra. If you're a beginner and something feels sketchy, ask before you power up. Nobody here will judge you for it.
What's not allowed
Nothing illegal, hateful or obscene
Don't post content that is illegal, false, defamatory, abusive, hateful, harassing, threatening, obscene, profane, sexually explicit or adult, or that invades another person's privacy, or anything that violates the law of your country. This applies to your profile and signature as well as your posts.
Respect copyright
Don't post copyrighted material (schematics, photos, articles, firmware) unless you own it or have the owner's permission. Link to the source and credit the author instead of re-hosting other people's work. The full copyright and takedown process is in the Terms of Service.
No spam or self-promotion
No spam, flooding, chain letters, pyramid schemes, or unsolicited advertising. Sharing your own build videos or project site is welcome, in your signature, your profile, and on-topic inside a thread where it actually helps. Registering just to drop links, or to sell something, is not.
AI content stays honest
This forum is a conversation between people. Passing off AI-generated text as your own answer is not allowed. AI material is fine only as a clearly-attributed quote (say which model and give the prompt) that you have checked yourself against a reliable source. Build logs, record claims and canon articles must be your own work. (An openly-labelled site assistant, if we ever add one, and answers you wrote with a tool but verified and stand behind, are fine.)
Protect privacy
Don't post other people's personal information: no addresses, real names, workplaces or photos of people without consent. Share your own only if you want to, remembering that the internet keeps everything.
Your account and the Marketplace
One person, one account
Keep to a single account and choose an appropriate username. Never share your password (staff will never ask for it) and never post from someone else's account. Use a strong, unique password. Creating new accounts to evade a ban gets those accounts removed too.
Marketplace: at your own risk
The Marketplace is a notice board, nothing more. The site is not a middleman, escrow or party to any trade, and disputes between buyers and sellers are not moderated. Describe the condition and the hazards of what you're selling honestly, and don't list anything illegal where you or the buyer live. Take part in the community before you sell. Accounts created purely to sell are removed.
Reporting, moderation and appeals
See a problem? Report it
Use the flag button on the post rather than replying to argue. A flag goes to the moderators, who review it. The more reliable your past flags, the more weight yours carries. We can't read every message, so reporting is how problems actually reach us.
How consequences work
Breaking the rules escalates: a private warning first, then a temporary suspension (typically 7–30 days), then a ban for repeated or serious violations. Spam bots and obvious bad actors are removed on sight. Every moderator action is recorded with a reason, so enforcement is consistent rather than arbitrary.
The final word, and appeals
Moderators and the site owner have the final say. If you think a decision was wrong, appeal by private message to the owner, calmly, with the details. We'd much rather fix a genuine mistake than lose a good member over a misunderstanding.
Danger: high voltage. Everything here is educational; build and operate at your own risk, and read the safety guide first. See also the Terms of Service and Privacy Policy. These rules will evolve as the community grows.