A Simple 6DOF Hall Effect ‘Space’ Mouse

The 3DConnexion Space mouse is an interesting device but heavily patent-protected, of course. This seems to just egg people on to reproduce it using other technologies than the optical pickup system the original device uses. [John Crombie] had a crack at building one using linear Hall effect sensors and magnets as the detection mechanism to good — well — effect.

Using the SS49E linear Hall effect sensor in pairs on four sides of a square, the setup proves quite straightforward. Above the fixed sensor plate is a moveable magnet plate centred by a set of springs.  The magnets are aligned equidistant between each sensor pair such that each sensor will report an equal mid-range signal with zero mechanical displacement. With some simple maths, inputs due to displacements in-plane (i.e., left-right or up-down) can be resolved by looking at how pairs compare to each other. Rotations around the vertical axis are also determined in this manner.

Tilting inputs or vertical movements are resolved by looking at the absolute values of groups or all sensors. You can read more about this by looking at the project’s GitHub page, which also shows how the to assemble the device, with all the CAD sources for those who want to modify it. There’s also a detour to using 3D-printed flexures instead of springs, although that has yet to prove functional.

On the electronics and interfacing side of things, [John] utilises the Arduino pro micro for its copious analog inputs and USB functionality. A nice feature of this board is that it’s based on the ATMega32U4, which can quickly implement USB client devices, such as game controllers, keyboards, and mice. The USB controller has been tweaked by adjusting the USB PID and VID values to identify it as a SpaceMouse Pro Wireless operating in cabled mode. This tricks the 3DConnexion drivers, allowing all the integrations into CAD tools to work out of the box.

We do like Space Mouse projects. Here’s a fun one from last year, an interesting one using PCB coils and flexures, and a simple hack to interface an old serial-connected unit.

 

Build A DIY Space Mouse For A More Efficient CAD Workflow

When you find yourself doing a lot of work in 3D modelling, you occasionally wish for something more capable than the humble two-dimensional mouse. A space mouse is a great tool in this regard, and [Salim Benbouziyane] was inspired to build his own.

[Salim] started his work with research, by watching a teardown of a Connexion Space Navigator 3D mouse. This informed him of the basic functionality and the workings inside. The commercial product appears to use an optical sensor setup, but [Salim] decided to go with a magnetic sensor setup instead due to the parts he had on hand. Namely, a 3-axis magnetometer which seemed perfect for the task.

The build uses a motion platform mounted on six springs which translates and rotates in three dimensions as required. The magnetometer is mounted on the platform above a stationary set of neodymium magnets. Thus, when the platform, and thus sensor, moves, the magnetometer’s output can be used to determine the motion of the platform and translate that into useful viewport commands for CAD software. A RP2040 is charged with reading the magnetometer and acting as a USB HID device. It’s all wrapped up in a neat 3D-printed housing.

For now, it’s a little simpler in its operation than a full 6 DOF Spacemouse, but it nonetheless has helped [Salim]’s workflow improve. A good peripheral like this can be a real boon on the desktop; we’ve seen a few DIY projects in this realm for just that reason. Video after the break.

Continue reading “Build A DIY Space Mouse For A More Efficient CAD Workflow”

Junkbox Confidential

Thomas Edison famously quipped “To invent, you need a good imagination and a pile of junk.” Amen, brother. My personal junk pile (ahem, collection of pre-owned electromechanical curiosities) is certainly a source of spare parts, but also a source of surprise and wonder. Sometimes the junk itself spurs the imagination, but sometimes junk is just junk.

There are pieces of used gear that I bought for some particular plan, maybe a decade ago?, and totally forgot. While it’s fun to rediscover them — I bought six used super-soaker pump assemblies, and summer is just around the corner — the sad truth is often that the forgotten pieces were forgotten for a reason. Whatever kooky idea I had at the time has faded, and the parts are all that’s left.

But among these miserable creatures, there are some absolute gems. Parts that continually call out to be used. Bits that would fire even Thomas Edison’s imagination. Unforgetable junk.
Mostly, it’s their physicality that calls out to me. I have a stack of old 5″ hard drive platters, gutted, and converted into essentially a rotary encoder. For years, I used it as a USB scroll wheel on my desk, but most recently it has made reappearances in other goofy projects — a music box for my son that played notes in a row depending on how fast you spun it, and most recently a jog wheel for a one-meter linear motion project that hasn’t really found its full expression yet, but might become a camera slider. Anyway, when I needed a nice physical rotary encoder knob, the hard drive was just sitting there waiting to be used. Continue reading “Junkbox Confidential”