It was basically working, except for its completely depleted battery. Hooked up to a 36v power supply, it powered up and all seemed ok.

Software

Following a guide posted by Emanuel Feru, I managed to re-flash the firmware to enable a 2 axis joystick input. This is an excellent guide and it contains everything you need to know and do.

I made some adjustments to the code for my use case and you can find it here.

Hardware

The most important criteria was to keep everything inside the beer crate as much as possible. This is what I came up with:

Basically, the mounting brackets for the motor shafts were cut off from the rest of the aluminium casting of the hoverboard and bolted to a welded structure designed to fit into the crate. After that, mounting the driver board, button brackets and battery was just a matter of rivnuts and cable ties.

The crate has some protuberances on the inside which rubbed against the tires, so those had to be ground off, but other than that, the crate has no changes made to it.

Bolted on a plywood seat and a fake (for now) headlight and voila:

Conclusion

There are some issues that still need to be addressed.

The biggest is that because all the wheels are so close together, it’s pretty unstable. I really had to dial the max speed and acceleration values down to keep it safe. Also the very stiff steel structure and stiff ‘tires’ make it lose traction if the surface you are riding on is bumpy. In effect, if one wheel is in a slight depression on the road, it just spins freely because there is no suspension or flex in the structure.

Another issue is that currently the joystick that is used to input speed and direction is a pair of middle resting potentiometers typical for a joystick module. What this means is that the input to stop the cart from turning or moving is half of the ADC value the board can measure. Therefore, if the driver falls off, but holds on to the joystick and the connection breaks, the BeerKart will hurtle off into the distance looking for the most expensive car it can find. And let me tell you, it does a great job finding expensive cars. The last time it happened it was an Audi.

Thanks for reading!

Check out the new video as well, if you want to see a build montage and a bit of the BeerKart in action:

The post The BeerKart appeared first on G00.

So, with Mach3 out of the picture, I decided to dual-boot LinuxCNC. The problem with this was, mainly, that I also have a laser cutter that comes with RDWorks which only works on Windows. This already meant a loss of productivity because I couldn’t use both machines at the same time. Nevertheless I got LinuxCNC to work, but then after having difficulties getting used to it,  and realising that I wouldn’t be able to use Solidworks or Fusion360 to CAD/CAM the parts, I finally decided to convert the machine to USB.

In order to do that, I whipped up a quick USB to parallel port adapter using an arduino nano on a perfboard and installed GRBL on it. You can get it here. The schematic of the board doesn’t exist, because basically it’s just GRBL pinout -> Driver board pinout. All wires.

I’ve used GRBL to drive DIY CNC’s before, and it was nice, but it had one big shortcoming. The feed override during machining wasn’t happening in real-time. So you couldn’t adjust the feed while milling difficult materials except after the current running command was finished. The latest version (1.1f) has this capability and from my point of view, GRBL is now perfect.

You can see it hanging on the left of the picture off the parallel port of the driver board.

It’s still missing limit switch, probing and spindle PWM connections, but it’s a start. By the way, the original spindle controller PCB has PWM input capability so it’s just a question of adding a connector from the arduino adapter board to the spindle controller.

Having converted the machine to GRBL meant that I could now use bCNC to drive it. This is an excellent piece of software, also free, also open source, written in Python. It has a bunch of features including generatic g-code from dxf files, making text engravings, adding tabs to the g-code to keep the cut part from flying away and breaking your mill. You can get it here. The user interface is very friendly and I cannot recommend it enough! Here is a screenshot from the bCNC github:

Here’s a test I was able to make with the Fusion360 – bCNC workflow:

(about 50mm/min, 10.000rpm with a 2mm, 3 flute endmill with WD40 as coolant)

Stay tuned for more CNC related posts!

The post GRBL+bCNC=Love appeared first on G00.

I detailed this process in an earlier post here:

Laser Marking Steel – the dry moly lube way

The post Laser Marking Stainless Steel appeared first on G00.

The post Electronics components organized. appeared first on G00.

Design-wise the course I took was to use a lamp boom/arm and mount the fan on that, so it could be positioned as close to, or over the soldering job.

Half an hour of solidworks later, I had 3 laser cut parts. Two grills and a spacer consisting of 5 and 3mm acrylic to get to and 8mm space to accomodate 2 sheets of filter material. With the filter I went the only way I knew which was using an activated charcoal foam sheet which is sold for exhaust hoods. So I cut it out in the shape of the spacers.

Then I just dismantled the cheapest boom-arm lamp I could find and mounted the fan onto that. Of course it took me three tries to get the holes right. Tired, I guess.

All assembled, and waiting for a speed controller:

On to the speed controller. I briefly thought about using an Arduino to provide the PWM for the 4 wire fan I used, but then I realized I hadn’t used a really old friend in a long time. My good old buddy, the 555 timer. I found a schematic online to provide the high frequency PWM for 4 fire fans and built the schematic on a small perfboard after trying it out on the breadboard first. This way, I didn’t need any voltage regulators and I saved loads of space.

I’ve fallen in love with this lamp arm. It’s so cheap (around 5 euro) and versatile! I also built a microphone adapter for it, for a friend of mine.

The post Fume extractor on a boom-arm appeared first on G00.