DIY Vacuum Chamber Proves Thermodynamics Professor Isn’t Making It All Up

[Mr_GreenCoat] is studying engineering. His thermodynamics teacher agreed with the stance that engineering is best learned through experimentation, and tasked [Mr_GreenCoat]’s group with the construction of a vacuum chamber to prove that the boiling point of a liquid goes down with the pressure it is exposed to.

His group used black PVC pipe to construct their chamber. They used an air compressor to generate the vacuum. The lid is a sheet of lexan with a silicone disk. We’ve covered these sorts of designs before. Since a vacuum chamber is at max going to suffer 14.9 ish psi distributed load on the outside there’s no real worry of their design going too horribly wrong.

The interesting part of the build is the hardware and software built to boil the water and log the temperatures and pressures. Science isn’t done until something is written down after all. They have a power resistor and a temperature probe inside of the chamber. The temperature over time is logged using an Arduino and a bit of processing code.

In the end their experiment matched what they had been learning in class. The current laws of thermodynamics are still in effect — all is right in the universe — and these poor students can probably save some money and get along with an old edition of the textbook. Video after the break.

Continue reading “DIY Vacuum Chamber Proves Thermodynamics Professor Isn’t Making It All Up”

Professional CNC Vacuum Table Holds Workpieces with Ease

If you do a lot of one-off parts on your CNC machine you’ll know setup is the worst part of the process. Usually you’re using scrap material, you have to figure out how you’re going to clamp it, make sure the the piece is big enough to use, etc etc. Wouldn’t it be nice to just throw the material on the bed and start machining? Well, with a vacuum table as nice as this, you pretty much can!

[Jack Black] has an awesome CNC machine. As he’s been expanding his prototyping abilities, he decided he needed a better way of securing work pieces for machining, so he machined a two-piece aluminum vacuum table.
Continue reading “Professional CNC Vacuum Table Holds Workpieces with Ease”

Robotic Vacuums Get Torn-down For Design Showdown.

Fictiv runs a 3D printing shop. They have a nice interface and an easy to understand pricing scheme. As community service, or just for fun, they decided to tear-down two robot vacuums and critique their construction while taking really nice pictures.

The first to go is the iRobot 650 model. For anyone who’s ever taken apart an iRobot product, you’ll be happy to know that it’s the same thousand-screws-and-bits-of-plastic ordeal that it always was. However, rather than continue their plague of the worst wire routing imaginable, they’ve switched to a hybrid of awfulness and a clever card edge system to connect the bits and pieces.

The other bot is the Neato XV-11. It has way fewer screws and plastic parts, and they even tear down the laser rangefinder module that’s captured many a hacker’s attention. The wire routing inside the Neato is very well done and nicely terminated in hard-to-confuse JST connectors. Every key failure point on the Neato, aside from the rangefinder, can be replaced without disassembling the whole robot. Interestingly, the wheels on both appear to be nearly identical.

In the end they rate the Neato a better robot, but the iRobot better engineered. Though this prize was given mostly for the cleverness of the card edge connectors.

DIY Vacuum Table Makes Lasering Even Easier

If you’ve ever tried to laser flexible rolls of material you’ll know it can be really annoying to setup in the laser cutter.

Most of the time we use magnets, but then you have to make sure the magnets are clear of the work path — and then you end up wasting extra material… It’d be amazing to have a vacuum table that just sucks down your work piece to keep it in place! As it turns out, it’s not that hard to make!

After getting frustrated lasering warped material themselves, [Martin Raynsford] and the gang decided to make their very own vacuum table — using a laser cutter of course. Continue reading “DIY Vacuum Table Makes Lasering Even Easier”

Hacklet 87 – Roomba Projects

First introduced in 2002, The iRobot Roomba was conceived as a robotic vacuum cleaner. Just about every hacker, maker, and engineer out there immediately wanted one. The Roomba proved to be more than just a vacuum though; it was the perfect base for any household robotics project. Before long Roombas were being hacked to do way more than sweep your floor. iRobot recognized this, and added a hacker friendly serial port to later model Roombas. They even released a vacuumless version called the iRobot Create. Thousands of projects have literally ridden on the wheels of the Roomba. This week’s Hacklet is all about Roomba projects.

roomba1We start with [fuzzie360] and Poor Man’s Raspberry Pi Turtlebot. [Fuzzie360] has their Roomba running Robot Operating System (ROS). ROS actually is running on an on-board Raspberry Pi. While Willow Garage may be out of business, ROS lives on as an open source project run by Unbounded Robotics. Installing it can be a chore though. While [Fuzzie360] hasn’t given a full tutorial, they have offered to give advice if and when you get stuck.

A Raspberry Pi would be overkill for the simple suite of sensors built into the Roomba, but it’s perfect for [fuzzie3680’s] modified setup with a Microsoft Kinect. [Fuzzie360’s] goal is to have a robot that can vacuum the hostile territory of a university apartment.

 

roomba2Next up is [Sircut] who upgraded his Roomba’s power cell. Early Roombas were designed to use Nickle Metal Hydride (NiMH) batteries. The individual cells are built into a proprietary iRobot battery pack. NiMH can’t hold a candle to Lithium Ion batteries though. Lithium Ion cells are very common these days in devices like cell phones and laptops. In fact, [Sircut] used 18650 sized laptop cells for this upgrade. [Sircut] also added the essential LiIon battery protection circuit to make sure those cells stay happy. A voltmeter provides a visual reference that the batteries aren’t becoming overcharged. An upgrade like this will likely double the Roomba’s runtime, but it does come at a cost. Roomba’s original charge dock can no longer be used as the on-board charge circuitry isn’t designed for LiIon battery charge algorithms.

roomba3Next is [Marcel Varallo] with Robot Wars for the Commuter. How does the IT department blow off steam? Fighting robots of course! Unfortunately, [Marcel’s] coworkers aren’t all programming mavens. Hopefully some programming is in the cards for them down the road. For now though, [Marcel] has created a robot fighting league using nearly stock Roomba robots. Each bot gets a set of 3 balloons and 3 pins. A balloon represents a life. Once your lives are all popped, you’re dead! [Marcel] also created an upgrade system where winning ‘bots can move on to stronger weapons like flamethrowers. During his research, [Marcel] found out that the brushes in his Roomba are powerful enough to sweep dust and debris up without the vacuum enabled. So he’s disabled the vacuums for longer cleaning battle times.

roomba4Finally we have [Fredrik Markström] and ESP8266 controlled Roomba. [Fredrick] is hacking an ESP8266 module to be the main computer of this little Robot. Of course, a ‘8266 means it will be carrying WiFi, so this robot needs to have a web interface. [Fredrik’s] first problem was powering the ESP8266. The Roomba’s battery runs around 15 volts, which is definitely not friendly to the 3.3 volt ESP8266. A switching DC to DC converter was in order, and [Fredrik] found the perfect candidate on eBay. The ‘8266 will control the Roomba through the serial interface included on all the current models. [Fredrik] has big plans for this ‘bot, including navigation and advanced vacuuming algorithms.

If you want to see more Roomba projects, check out our new Roomba project list! If I missed your project, don’t be shy, just drop me a message on Hackaday.io. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Adventures With Vacuum Deposition Power Supplies

[Jerry Biehler] called this a “fail of the week”, but of course failure is just another part of the hacker adventure. Fail and fail often!

[Jerry] has been slowly assembling a vacuum deposition system. These systems let you deposit thin films on a substrate. Vacuum deposition systems have all sorts of exciting applications, not only are they used in semiconductor manufacturing, but as [Ben Krasnow] has shown can create conductive transparent coatings. They’re even sometimes used for silvering mirrors.

A common feature of these systems is that they require high voltage, we’re not talking a few hundred volts or even a few thousand volts. But 10 to 20 kilovolts. You need such a high voltage in order to accelerate electrons and ions, which are used to eject atoms from a source and deposit them as a thin film on a substrate.

It was this HV supply [Jerry] was working on, cobbling the system together from parts found on eBay. Unfortunately [Jerry] could only reach 9kv unloaded, which we’d expect to drop considerably under load. So [Jerry] has now found a different solution. But this teardown and writeup still makes great reading.

We’re left to pondering on what projects the spare parts could be useful for: “I might be able to series the secondaries and get 30kv at 500ma! That would make one hell of a bug zapper! Actually these transformers scare the hell out of me….” me too Jerry! Me too!

Super Cheap Vac Attachment Helps Find Small Dropped Parts

It’s pretty much guaranteed that when working with small parts, you will drop at least one. This phenomenon is just how the universe works, there is no avoiding it. Digging though a carpet or dirty shop floor usually results in frustration and subsequent scrambling for a replacement part. Tired of crawling around on his knees looking for runaway parts, [Frank] decided to do something about it. He made a vacuum attachment that helps with the search… and it’s made from stuff he had kicking around the house.

The idea here is to suck up and contain the part without having it making it’s way into the vacuum. To do this there would have to be an intermediate chamber. For this, [Frank] used a multi-pack CD container. This was a great choice because it is clear, allowing him to see what enters the container, and it unscrews quickly making it easy to retrieve the tiny part. The inlet and outlet connectors are made from PVC and are attached to the CD container’s base with adhesive. To keep the debris from getting past the CD container, an old kitchen strainer was cut up and the screen material was used to only let air pass. Once a shop-vac is connected to the outlet pipe, the sucking can begin. [Frank] shows that he has to sift through a bunch of shop-floor crud to find his dropped screw, but it works!