How to Set Up Alerts for Used 3D Printers and CNC Machines on Craigslist and eBay

Used 3D printers and desktop CNC machines have a real market on Craigslist and eBay. Makers upgrade constantly - someone buys a Bambu Lab X1C, their old Prusa MK4 goes up for sale. A Shapeoko 4 from a hobbyist who switched to a bigger machine shows up at 40-50% off retail. These are high-value items, and the listings that are priced right don't stick around. This guide covers how to set up alerts so you're notified the moment a new 3D printer or CNC listing goes live - before the other buyers in your area even know it's there. ## The Problem With Manual Searching Craigslist has no built-in alert system. If you want to know when a new 3D printer is listed in your area, you have to refresh the search page and check yourself. For a category where good deals are sporadic but move fast when they appear, that's not a workable approach. eBay has saved searches that send email notifications, but they typically batch those emails on a daily basis. A Bambu Lab P1S listed for $350 (half of retail) on eBay in the evening might have 20 watchers by the next morning when eBay sends your digest. It's already sold. [LurkMor](https://lurkmor.com) solves both of these. It monitors Craigslist and eBay for new listings that match your search and sends you an alert immediately - not in a daily batch. Here's how to set one up: 1. Go to [LurkMor.com](https://lurkmor.com) 2. Enter your search term ("Bambu Lab," "Prusa MK4," "Shapeoko," "3D printer," etc.) 3. Set your location and radius if you're searching locally 4. Enter your email address 5. Save the alert You can run multiple searches. If you're watching for 3D printers in general and a specific CNC model, set up separate alerts for each. ## What to Search For Printers and CNC machines get listed under a wide variety of titles depending on how technical the seller is. Cover both ends: **Brand and model searches** catch sellers who know what they have: - "Bambu Lab" or "Bambu X1" or "Bambu P1S" - "Prusa" or "Prusa MK4" or "Prusa Mini" - "Creality" or "Ender 3" - "Shapeoko" or "Carbide 3D" - "X-Carve" or "Inventables" - "Onefinity" (these are large and heavy - sellers are often very motivated) - "Voron" (enthusiast builds - usually priced more carefully but watch for "project" listings) **Category searches** catch sellers who don't know or don't use the brand name: - "3D printer" - "FDM printer" - "resin printer" - "CNC router" - "CNC machine" - "laser cutter" (if that's your interest) **Opportunity keywords** for machines priced to move: - "3D printer lot" - multiple machines at once, often a steal - "3D printer project" - incomplete builds, often cheap - "CNC incomplete" - started builds with expensive parts already bought ## Why Speed Matters Here Used 3D printers and CNC machines are niche enough that there aren't hundreds of buyers watching every listing. But the buyers who are watching tend to be informed, patient, and ready to act quickly. When a Prusa MK4 shows up at $300, the people who have been monitoring for it don't wait to think about it. Higher-value machines - Bambu X1C, Onefinity, large-format CNCs - can sell in hours when priced right. The seller often gets multiple messages within the first day and goes with whoever responded first and confirmed they'd buy it. For a category where good listings are infrequent, being fast when one appears matters more than in categories with constant inventory. You might wait two weeks for a specific machine to show up. When it does, you want to be the first call. ## Craigslist vs. eBay for This Category Both are worth monitoring, but they serve different needs. **Craigslist** is better for: - Local pickup (important for large CNC machines that can't ship reasonably) - Cash deals below market from sellers who just want the machine gone - Finding machines from people upgrading who aren't interested in the eBay hassle **eBay** is better for: - Specific models you can't find locally - Smaller printers that ship reasonably - Price research - use the sold listings filter to see what machines actually sold for before you negotiate or bid The sold listings filter on eBay is essential for this category. Asking prices on active listings are often wishful. Sold listings show you the actual market. Search your target model, filter to completed/sold, and you'll know immediately whether a listing is priced right or overpriced. ## Evaluating Listings When an Alert Fires When you get an alert, you want to be able to triage quickly. A few things to check right away: - **Does the seller have photos of recent prints?** This is the fastest signal that the machine was working before listing. - **What's the reason for selling?** "Upgrading to Bambu" is a good sign. "Stopped working" is not. - **What's included?** Filament, accessories, and a spool holder add real value. Missing a build plate or a key component changes the math. - **For CNC: is the wasteboard included?** A chewed-up or missing wasteboard shows heavy use but isn't a dealbreaker. Ask if the spindle or router is included - some sellers keep it. - **Does the price make sense?** Compare to the eBay sold listings you've already looked up. If a Prusa MK4 is going for $250-300 on eBay used and this one is $175 local pickup, that's real. ## Setting Up a Practical Alert Stack If you're actively hunting a 3D printer or CNC, here's a setup that works: - Alert 1: Your target brand and model (narrow, specific) - Alert 2: "3D printer" with your area and a price ceiling - Alert 3: "CNC router" or "CNC machine" with your area - Alert 4: A broader term like "resin printer" if you're open to that category LurkMor runs all of these in parallel with no extra effort. You set them up once and hear about new listings as they appear. One note: LurkMor alerts on new listings only. When a seller posts a new item that matches your search, you get notified. This is the right approach for this category - you want to know about new inventory as soon as it hits, not chase price changes on listings you've already seen. ## Start Watching Now If you've been casually checking Craigslist for a 3D printer or CNC machine and keep coming up empty, the issue isn't that the deals don't exist - it's that you're seeing the listings after they've already moved. Go to [LurkMor.com](https://lurkmor.com), set up an alert for the make or model you're after, and let it run. The upgrade cycle in the maker community is constant. Someone nearby is going to list a good machine in the next few weeks. You might as well be the first to hear about it.