Outfitting a small lab is strangely hard. The big catalogs are built for institutions: racks come in case packs, custom anything requires a quote request and a minimum order, and the cheap imports that do come in small quantities tend to arrive warped, brittle, or sized for the wrong tubes. Meanwhile the actual need is usually modest: a teaching lab wants a rack per bench, a vet clinic wants one per exam room, a startup wants four racks in four colors so nobody mixes up samples. That gap is exactly the kind of problem a US additive manufacturing shop is built for, and it is why we have started producing lab equipment alongside our engineering parts. Our newest release is a test tube rack 4 pack for 15 mL conical centrifuge tubes, and the story behind it says a lot about how modern small-batch manufacturing works.
I just need a few test tube racks for 15 mL conical tubes, not a case of 50. Where do I buy that?
You can buy a four pack of 12-well benchtop racks for standard 17 x 120 mm conical centrifuge tubes, made to order in the USA, directly from a small manufacturer instead of a catalog. Ours ships as four racks, one each in red, white, blue, and yellow, so every project, user, or workstation gets its own color. Each rack holds twelve 15 mL conical tubes upright in a 4.5 x 3.5 x 2.5 inch footprint and weighs 2.8 ounces. The wells measure 18.44 mm, sized for the industry standard 17 mm tube and accepting tubes, vials, and dropper bottles up to 18 mm. Two-point support, a deck ring plus a centering pocket set 50 mm apart, keeps tubes standing straight instead of leaning. There is a drain hole under every well so rinse water passes through instead of pooling, the open sides keep labels and volume graduations visible, and the press fit deck, base, and side panels pull apart by hand for cleaning, no tools or hardware. It wipes clean with isopropyl alcohol or warm soapy water, though it is not autoclavable, and we say so plainly on the listing.
Why a 3D printing shop is making lab equipment at all
Lab gear is a natural fit for additive manufacturing. The parts are small, the geometry matters more than the material volume, and demand comes in exactly the quantities big factories hate: four racks, one holder, two replacement lids. Because each rack is printed to order, there is no warehouse of stale inventory and no minimum order quantity propping up the economics.
There is also a trust problem in this category, and we attack it with measurement. Every dimension published on our rack listing was taken with calipers on a finished rack, not estimated from a CAD drawing. That habit comes from our engineering work, where a number nobody verified is treated as a number nobody knows. If you have ever bought a rack whose wells were somehow too tight for the tubes printed on the box, you know why this matters.
Our lab uses an odd vial size and nothing on the market fits. Can someone make a custom rack?
Yes, a custom rack sized to your exact tubes or vials is a routine job for a shop like ours, and small quantities are the whole point. Send us the tube diameter and height, or even just the vial itself, and we design the rack in CAD, print it, verify the fit with gauges, and ship it. If you need a holder that matches an existing piece of equipment, a discontinued caddy, or a bracket that mounts to a specific instrument, we can 3D scan and reverse engineer the original part and rebuild it. For one-offs and short production runs with fast turnaround, that is what our build and ship service exists for.
If you are an engineer, a lab manager, or a laboratory supply buyer with a product idea or a recurring small-batch need, we would like to hear from you. Email info@dcadditivepros.com with what you are trying to hold, mount, or organize, and we will tell you honestly whether it is a good fit for additive manufacturing.
What 3D printed lab gear is good at, and what it is not
We are direct about the limits because that is how repeat customers happen. Printed polymer racks and organizers are excellent for benchtop organization, sample staging, teaching labs, mobile kits, and replacing discontinued plastic parts. They are not a substitute for autoclavable stainless or PPS hardware in sterilization workflows, and we will tell you when your application calls for something we do not make. Everything here is educational information about equipment, not medical advice, and our lab products are organizational tools, not medical devices.
Frequently asked questions
Are 3D printed test tube racks autoclavable?
Ours are not autoclavable. They wipe clean with isopropyl alcohol or warm soapy water, and the press fit panels pull apart by hand so you can clean every surface.
What size tubes fit a 15 mL conical tube rack?
The industry standard 15 mL conical centrifuge tube measures 17 x 120 mm. Our rack's wells measure 18.44 mm, so they hold that standard tube plus vials and dropper bottles up to 18 mm in diameter.
Can I order custom lab racks in small quantities?
Yes. Because our racks are printed to order, there is no minimum order quantity. One custom rack, four racks in four colors, or a short production run are all normal jobs.
How do I get a custom lab part designed and made?
Email info@dcadditivepros.com with the dimensions of the tubes, vials, or equipment involved, or send the physical part. We design in CAD, print in the USA, verify fit with gauges, and ship the finished piece.