Privacy at Rocket Builder

Last updated 2026-10-28

Rocket Builder (rocket.quiverdesignworks.net) is run by Quiver Design Works LLC. It's used by kids, families and classrooms, so we keep as little as we can. You don't need an account to design, build, download or save a rocket.

Using Rocket Builder without an account

• Rockets you save: we keep the name you give it and its settings (sizes, motor, fins and so on), so its share link (/d/…) opens it again. Anyone you give the link to can open it.
• In your browser (local storage on your device, not sent to us unless noted): the light/dark choice, panel sizes, whether you finished the tutorial, rockets you're comparing, and the list of rockets saved in this browser with the key that lets this browser change them (the server keeps only a scrambled copy of that key).
• Builds: the settings of a rocket you build are held in the server's memory for a while so the preview and downloads work, then dropped.

Accounts

Accounts are for grown-ups and older students who want their rockets on any device, teachers who make classes, and anyone ordering a printed rocket. When you make one we keep:

• your email address, which is how you sign in;
• your password, only as a one-way scrypt hash (we can't see or recover the password itself);
• your account settings (for now, whether to skip the tutorial) and the rockets you save while signed in;
• a sign-in cookie (rb_session) that keeps you signed in for 30 days. The server stores only a hash of it, and signing out deletes it.

The sign-up form asks for your birth year. We use it once to decide whether you can make an account and don't save it. Children under 13 can't make an account: they can still build and save rockets on their device, and hand them in with a class code from their teacher. If the answer is no, nothing you typed is saved; a cookie with no personal details (rb_signup_wait) just keeps the sign-up form giving the same answer for 24 hours. If we learn that a child under 13 has an account, we delete it.

We don't send newsletters or marketing email, and we don't sell or rent email addresses.

Class sharing (students and teachers)

A teacher signs in with an account and makes a class, which gets a short class code. Students don't make accounts. To hand in a rocket, a student types the class code and a first name or nickname (the form asks them not to use their full name, and turns away anything that looks like an email address or phone number). For each rocket handed in we keep:

• the nickname,
• the rocket's name, its settings and its numbers (height, fins, nose, stability score, the motor we suggest, predicted height and so on), worked out by our server,
• when it was handed in.

Nothing else about the student is kept with it: no email, IP address, device, cookie or location, and nicknames are left out of our server logs. The student's browser remembers the class code, and the nickname until the tab is closed, so handing in again is quicker. Only the teacher who made the class can see what was handed in. A class and everything in it are deleted automatically 180 days after the class is made, or straight away when the teacher deletes the rocket or the class.

For schools: teachers who use class sharing do so on behalf of their school, for classroom use. The school is responsible for any notice to parents or consent its own policies or the law require. Teachers and parents can ask us to delete a class or a student's rocket at any time (see Contact).

Printed-rocket orders

Ordering a printed rocket needs an account. We keep the order (the rocket, quantity, colour, your notes), your account email and the shipping address, so we can print and post it. Paid orders go through Stripe's hosted checkout: you type your card details on Stripe's page, and they never reach this site. Stripe tells us the shipping address and phone number you gave it, the amount paid and the email for the receipt; Stripe's privacy policy covers what Stripe keeps. Order details are also shared with the Quiver Design Works order desk on quiverdesignworks.net, copied to our print workshop's computer, and emailed to us (the shop owner) when an order comes in. We keep order records for our business and tax records.

Services that help run the site

• Fly.io hosts the site and its database (in the United States). Like most hosts, it keeps short-lived server logs of requests, which can include network addresses. Our sign-in and hand-in limits hold network addresses in memory for a few minutes to stop abuse; they aren't saved.
• Stripe handles payments for printed rockets (above).
• Resend sends one kind of email: a new-order notice to us. It doesn't email customers or students.

The fonts, 3D viewer and other code are served from our own site, so loading a page doesn't contact anyone else. Links to other sites (for example the Amazon links on Order supplies, which are affiliate links) follow those sites' own privacy policies once you click them.

Your choices

• You can use everything except orders and making classes without an account.
• Teachers can delete handed-in rockets and whole classes from the My classes page.
• To see, correct or delete your account, your saved rockets or an order, or (for parents and teachers) a student's hand-in, contact us. We'll check the request comes from you and then do it.

Contact

Questions or deletion requests: quiverdesignworks.net/#contact (Quiver Design Works LLC).

Changes

If what we keep changes, we'll update this page and the date at the top before the change goes live.

See also the file license for the rockets you download.