peristaltic pump

15 Articles

Fish Tank Dosing Pump Built Using Pi Pico

March 17, 2023 by 5 Comments

When you’re maintaining a fish tank, it’s actually quite important to get all your basic chemistry right. Mismanage things, and you’ll kill all the helpful bacteria in the tank, or kill your fish when things get too alkaline or too acidic. To help him get things just right, [yojoebosolo] built a custom dosing pump to maintain his fishtank.

The pumps themselves are small peristaltic pumps sourced from AliExpress. They can be had for under $10 if you look hard enough. Two of these are assembled into a PLA housing. Meanwhile, the brains of the operation is a Raspberry Pi Pico. It’s charged with running the pumps to a regular schedule, ensuring that just the right amount of chemicals are delivered when they are needed. It delivers 2 mL of Kalkwasser solution into [yojoebosolo’s] reef tank every ten minutes.  The pumps are switched on and off with a simple 5V relay.

If you’ve got a delicate and complex fish tank that demands only the best, building your own dosing pump may be the way to go. Off-the-shelf versions can be expensive, after all, so sometimes it makes sense to roll your own. Video after the break.

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Pump Up The Resin

February 13, 2022 by 13 Comments

Sometimes the best ideas are simple and seem obvious after you’ve heard them. [Danny] showed us a great idea that fits that description. He uses a peristaltic pump to move resin in and out of his print bed. (Video, embedded below.) Normally, you remove the tank and pour the resin out into a container. With the pump, you can leave the tank where it is and simply pull the resin through a tube. The process is slower than pouring, but not as messy and doesn’t risk damage to your FEP film.

You can also use the pump like a vacuum to clean up resin. According to [Danny], the biggest value is when working with very large printers. He shows a Peopoly Phenom which has a huge tank compared to the other printers he shows in the video.

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Stout Peristaltic Pump Fabricated From Scratch

January 12, 2022 by 18 Comments

The peristaltic pump is perhaps most well known for its ability to pump fluids without the pump mechanism coming into contact with the working fluid. This is key for food-safe applications and other situations where a pump could contaminate the fluid. [Maciej Nowak] has built a great example of such a pump, crafted out of aluminium from scratch.

The build video covers the machining process in detail, showing how the aluminium body was fabricated on the lathe before installing bearings and a silicone hose. The pump shaft was then fabricated, along with a set of brass rollers to press along the tube, creating the pumping action. The rollers were also lubricated in order to reduce friction on the tubing. Powering the pump is a small DC motor, sending drive via a small toothed belt, giving the finished build quite an industrial look.

We’re used to seeing plenty of 3D-printed pumps about the place. This build, while it requires a fully-equipped machine shop, is much tougher than anything plastic, and you could easily use it to break a window in an emergency too, an obscure feature nevertheless requested by some discerning pump customers.

[Maciej] shows off the build by pumping some green liquid, noting the peristaltic design requires no priming which makes operation much easier. It’s also bidirectional, and can be run very slowly if required.

Overall, it’s a build that shows off the benefits of working in metal as well as the great features of the peristaltic pump design. Video after the break.

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The Silent Dripper Dispenses Water Without Making Any Sound

November 19, 2021 by 6 Comments

Engineering is all about making a design that conforms to a set of requirements. Usually those are boring things like cost, power consumption, volume, mass or compatibility with existing systems. But sometimes, you have to design something with restrictions you might have never considered. [Devon Bray] was tasked with designing a system that could dispense single drops of water, while making absolutely no noise. [Devon]’s blog describes in detail the process of making The Silent Dripper, which was needed for an art installation called The Tender Interval by [Sara Dittrich].

The design process started with picking a proper pump. Centrifugal pumps can be very quiet due to their smooth, continuous motion, but are not suitable for moving small quantities of liquid. Peristaltic pumps on the other hand can generate single drops of liquid very accurately, but their gripping-and-squeezing motion creates far more sound. [Devon] still went for the latter type, and eventually discovered that filling up the pumping mechanism with lithium grease made it quiet enough for his purpose.

The pump was then mounted on a 3D-printed bracket that also contained the water feeding tube and electrical connections to the outside world. The tubing was fastened with zip ties to stop it from moving when the pump was running, and the pump itself was isolated from the bracket with rubber dampening mounts.

Another trick to silence the pump was the motor driver circuit: standard PWM drivers often cause audible whine from the motor coils because of their abrupt switching, so [Devon] went for a Trinamic SilentStepStick that regulates the current much more smoothly. The end result is a water dripper that makes less noise than a piece of tissue paper being crumpled, as you can observe in the video (embedded below) which also demonstrates the complete art installation.

We really like the mechanical design of the Dripper; as far as we’re concerned it would merit a spot in a gallery on its own. It would not be the first water dripping art project either; we’ve already seen a sculpture that apparently suspends droplets in mid-air. Continue reading “The Silent Dripper Dispenses Water Without Making Any Sound” →

Automated Watering Machine Has What Plants Crave: Fertilizer

May 14, 2021 by 19 Comments

We’ve seen countless automated plant care systems over the years, but for some reason they almost never involve the secret sauce of gardening — fertilizer. But [xythobuz] knows what’s up. When they moved into their new flat by themselves, it was time to spread out and start growing some plants on the balcony. Before long, the garden was big enough to warrant an automated system for watering and fertilizing.

This clever DIY system is based around a 5L gravity-fed water tank with solenoid control and three [jugs] of liquid fertilizer that is added to the water via peristaltic pump. Don’t worry, the water tank has float switches, and [xythobuz] is there to switch it off manually every time so it doesn’t flood the flat.

On the UI side, an Arduino Nano clone is running the show, providing the LCD output and handling the keypad input. The machine itself is controlled with an ESP32 and a pair of four-channel relay boards that control the inlet valve, the four outlet valves, and the three peristaltic pumps that squirt out the fertilizer. The ESP also serves up a web interface that mimics the control panel and adds in the debug logs. These two boards communicate using I²C over DB-9, because that’s probably what [xythobuz] had lying around. Check out the demo video after the break, and then go check on your own plants. They miss you!

Don’t want to buy just any old peristaltic pumps? Maybe you could print your own.

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VK-01 Is A Bartender You Don’t Need To Tip

August 1, 2020 by 15 Comments

[Donald Bell’s] robotic bartender entry into the 2020 Cocktail Robotics Grand Challenge is one of those things that sounds easy until you start getting into the details. After all, how hard is it to dispense some liquids into a glass? Harder than you might think. Sure there are pumps — [Donald] uses peristaltic pumps — but there’s also two Raspberry Pis, an ESP8622, and at least one more microcontroller lurking underneath. You can see a video about the device below.

Even if you don’t want a refreshing libation, you’ll probably like the VK-01’s Bladerunner cyberpunk styling. What we really enjoyed about the post was that it took you through the concept sketches, some of the design trades, and even a cardboard prototype.

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The Bolt-On Peristaltic Pump

October 27, 2018 by 8 Comments

With the proliferation of 3D printing in the new millennium, stepper motors are no longer those idle junkbox inhabitants you pulled out of a dot matrix in 1994 and forgot about ever since. NEMA standard parts are readily available and knocking about just about everywhere. Now, you can readily turn a stepper motor into a peristaltic pump with just a few simple 3D printed parts.

The pump consists of a bracket that fits on to a standard NEMA-14 stepper motor frame. A rotor is then fitted to the motor shaft, constructed out of a 3D printed piece fitted with a series of standard roller bearings. These bearings roll against the tubing, pumping the working fluid.

The design uses the bearings to squeeze outwards against the tube’s own elastic resistance. Frictional wear is minimised by ensuring the tube is only pressed on by the bearings themselves, avoiding any contact between the tubing and hard plastic surfaces.

While the design is in its early stages of development, we’d be interested to see a pump performance comparison against other 3D printed peristaltic designs – we’ve seen a few before!

[Thanks to Baldpower for the tip!]