r/3Dprinting

Welcome to R/3D Printing! Come for the Benchy, stay for the Calibration!

Founded March 2010 · Public — anyone can post

Updated Sep 9

/r/3DPrinting is a place where makers of all skill levels and walks of life can learn about and discuss 3D printing and development of 3D printed parts and devices.

Members

3,423,425

3.4M

Online now

—

not captured in the last snapshot

Posts per day

—

no sample yet

Comments per post

—

no sample yet

Growth · 7d

—

not enough history yet

Growth · 30d

+0.5%

+19K members · ≈33d

Published rules

9

1 mention promotion — quoted below

Last post

—

no sample yet

Distinct posters

—

no sample yet

Tracking since Aug 7 · growth spans are the real distance between snapshots, not rounded windows. Posts/day is measured from the community’s own newest posts on Reddit, not from what Prowlo happens to crawl.

Member growth

What works in r/3Dprinting

Every post in a recent sample, labelled by format. Share is how much of the sample used that format; average score is how it performed.

FormatShare of postsAvg score
Show & tell57%10,008
Discussion15%3,692
Question11%1,105
Rant7%9,054
How-to7%1,197
Promo4%27

Based on 74 posts sampled in September 2026. A sample, not the full history.

Median score
3,576
Top 10% score
18,524
Text posts
12%
Got no replies
7%
Busiest windows
Tue 22:00 UTC, Tue 19:00 UTC

Posting rules, in plain words

Self-promotion is allowed at a ratio — contribute before you post about yourself. Promotion goes in Monthly Purchase Advice Thread (Monthly, stickied to the top of the subreddit). Post flair is required.

  • Self-Promotion: Self-Promotion content can only be posted 14 days for free models and 30 days for paid models after your last self-promotion post. Specific other restrictions also apply, that you can read about in the full rules below.

Quoted from the community’s own published rules. Always re-read them before posting.

What a good comment looks like here

  • — Directly answers the original post's question or addresses its premise.
  • — Provides specific technical details or explanations (e.g., material, settings, design choices).
  • — Uses humor or relatable anecdotes.
  • — Offers constructive criticism or alternative solutions.
  • — Engages in playful banter or community in-jokes.

What r/3Dprinting's rules say about promotion

1 of 9 published rules mentions promotion, advertising or spam. Quoted from the community's own rules page, not summarised.

  1. Self-Promotion

    rule 3 of 9

    Self-Promotion content can only be posted 14 days for free models and 30 days for paid models after your last self-promotion post. Specific other restrictions also apply, that you can read about in the full rules below. This is an overview. Full rules: https://www.reddit.com/r/3Dprinting/wiki/communityrules/

    Removal reason shown to posters: self-promotion rule violation

The other 8

  • Posts must be 3D-printing-related
  • Requests for purchase advice must go in the stickied megathread
  • No Dangerous or Malicious Devices or Instructions
  • Community Behavior
  • Specific Day-Limited content
  • Other content restrictions
  • No Karma/Repost Bots
  • No Linking to Restricted Websites

Read from r/3Dprinting’s published rules on Sep 2. Communities change their rules without notice and enforce requirements (karma, account age, flair) that may live in the sidebar or automod rather than here — the source page is the authority.

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See the full lists on similar subreddits.

r/3Dprinting — frequently asked

How many members does r/3Dprinting have?

r/3Dprinting has 3,423,425 members as of our most recent crawl on Sep 9. Prowlo re-checks tracked communities on a rolling schedule, so this figure moves rather than sitting frozen at whatever it was when a scraper last ran.

Is r/3Dprinting growing?

Over the last ≈33 days r/3Dprinting changed by +0.5% — a gain of 19K members. We compare against the nearest snapshot we actually hold and state the real span rather than rounding it to a clean "30 days".

How active is r/3Dprinting?

We don't have a reliable posting-rate sample for r/3Dprinting yet. Subscriber count alone is a poor guide to whether a community is active, so treat this one as unverified until the next sample lands.

When was r/3Dprinting created?

r/3Dprinting was founded in March 2010 and is a public — anyone can post community. Age matters: an older community with steady growth has survived Reddit's moderation churn; a young one with a spike may not.

Can I promote my product in r/3Dprinting?

r/3Dprinting publishes 9 rules and 1 of them addresses promotion. The first, “Self-Promotion”, says: Self-Promotion content can only be posted 14 days for free models and 30 days for paid models after your last self-promotion post. Specific other restrictions also apply, that you can read about in the full rules below.… Read the full rule text on this page and the community's rules page before posting — moderator enforcement is the thing that actually decides.

How do I monitor r/3Dprinting for mentions?

Hit Watch on this page. Prowlo starts crawling r/3Dprinting into your Dataset — every new post indexed and embedded, searchable semantically, queryable by your AI agent over MCP, and able to trigger keyword alerts in Slack. Prowlo is read-only; it never posts on your behalf.

Can my AI agent read r/3Dprinting's stats?

Yes. Everything on this page is one MCP tool call away: catalog_get_subreddit returns r/3Dprinting's members, growth, promo tolerance and similar communities as typed JSON — free, no credits. Connect your agent to api.prowlo.com/mcp and it can vet the community and start watching it in the same conversation.

Watch these subreddits

Rankings go stale. Prowlo watches these subreddits daily and pings you the moment someone describes the problem you solve.

r/SaaS · 4m ago

“Our analytics bill tripled overnight. Actively shopping for an alternative this week — what’s good?”

Match · 86%Buying signal

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