Terms of Service

CommonGnd is a community forum and knowledge base about Tesla coils and high-voltage electronics. It is non-commercial (no ads, no paid tiers, no monetization) and exists for education and discussion between hobbyists and engineers.

Reading is open to everyone. To register you must be at least 13 years old (or the age of digital consent in your country, if higher). Accounts found to belong to someone under 13 are removed.

Choose an appropriate username, and keep your profile information clean and accurate. Anything inaccurate, misleading or vulgar may be removed, with or without notice, and may lead to sanctions. Use a strong, unique password and never reuse one from another site. Staff will never ask for your password, so never share it with anyone. Never post from someone else's account, and keep to one account per person. You are responsible for everything done under your account.

You agree not to post content that is illegal, false, defamatory, abusive, hateful, harassing, threatening, obscene, sexually explicit or adult, or that invades another person's privacy, or that otherwise breaks the law of your country. No spam, flooding, chain letters, pyramid schemes or unsolicited advertising. Pseudoscience (free energy, over-unity, electrogravitics and the like) is not allowed, per the Community Rules, and dangerous instructions must carry appropriate safety context.

You keep ownership of what you post. By posting, you grant CommonGnd a non-exclusive licence to store and display your content so the forum can operate. Canon knowledge-base articles are published under CC BY-SA 4.0; when we move material from a thread into the canon we credit the original author. You are solely responsible for the content you post.

Don't post copyrighted material (schematics, photos, articles, firmware) unless you own it or have permission. If you believe content here infringes your copyright, send a notice to that identifies the work, links to the infringing post, gives your contact details, and states in good faith that you are the owner or authorised to act for them. We remove or disable clearly infringing content within a reasonable time, and the poster may reply with a counter-notice. Knowingly false claims are not acceptable.

You are responsible for the images, videos and files you upload. Note that photos often contain embedded location data (EXIF/GPS). Strip it before uploading if you don't want people to see where the photo was taken, because anyone can download an image and read that data. Don't upload anything you don't have the right to share.

Threads may embed content from other websites (YouTube videos, images, and so on). Embedded content behaves as if you had visited the other site directly: it can set cookies and track your interaction under its terms and privacy policy, not ours. We embed YouTube for video. YouTube's terms and privacy policy apply to that content.

It is impossible for staff to confirm that every post is valid, and we do not actively monitor every message, so we are not responsible for the content posted, and we do not warrant that any information here is accurate, complete or useful. Posts express the author's views, not ours. If you see something objectionable, report it and we will remove it within a reasonable time if we judge that necessary. This is a manual process and may not be immediate.

Danger: high voltage. Tesla coils operate at lethal voltages. Everything here is educational; you build and operate entirely at your own risk. Read the Safety guide before you build or power anything up. Nothing on this site is a substitute for proper training or professional advice.

The Marketplace is a notice board only. The site is not a party to any trade, not a middleman and not an escrow. Deals are at your own risk and disputes between buyers and sellers are not moderated. Describe the condition and hazards of anything you sell honestly.

Moderators and the owner may remove content and suspend or terminate accounts that break these terms or the Community Rules, usually after a warning, but immediately for spam or serious violations. Your IP address is recorded with each post; it is used only to enforce bans or, in the event of a serious violation, to contact your ISP or the authorities.

You are responsible for your own content and for how you use anything you learn here. To the extent permitted by law, the site and its operators are not liable for damage arising from use of the forum or reliance on its content. Nothing here removes rights you have under mandatory local law.

We collect the minimum needed to run the forum, use no advertising or third-party trackers, and let you export or erase your data. See the Privacy Policy for details.

We may update these terms from time to time. Material changes will be announced on the forum; continued use after a change means you accept it.

Questions about these terms? Email .