DIY silent football wall

Here’s a DIY football wall we set up in our garden. It’s basically a metal frame with a very tight football net fastened between the metal rods. The ball bounces back about the same speed as it hits the net. Works really well. It is completely silent and cheap to set up.

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Bubble-counter for beer brewing

I’ve to make a sensor for counting bubbles in the beer fermentor I have downstairs in the basement. I had to work quickly to get some results, since the fermentation probably will slow down within a couple of days.

The idea is from this post and this post, essentially using an infrared diode + an infrared transistor to sense when a bubble passes through the air-lock. The demo-data is quite erratic (as seen below) :-) but the bubble-counter mechanism seems to work ok-ish (I don’t think I’m really counting actual bubbles, but the count is related at least). I should probably count over a longer period of time.

BubbleCounter

 

And the temperature is measures (with a separate MSP430 board and separate wifi-module) using DS18B20 1-wire sensor, bought on Aliexpress for 1.2 USD. It is encased in stainless steel, but I haven’t actually put it into the beer… it’s taped onto the outside of the bucket.

 

And since the above live feed will fade away in history as my brewing ends, here’s a screenshot:

ubidots

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Finally brewing beer again

I stopped brewing 11 years ago when I got kids, and finally I started the hobby again. I digged deep into my savings and bought a Braumeister. I have been thinking of making an automatic brewing machine of course, for many years, but in the end I just bought one. And I’m really pleased with the result. Ehh.. well, the beer isn’t finished yet so I haven’t tasted it, but it looks promising.

I’m brewing an Ale called Lucky Jack, and here are my notes:

  • Yeast: WLP001
  • Final volume 21 liters (approx)
  • OG: 1.045
  • Final: ? (not done yet… bubbling away)
  • Fermenting at approx 15C, which is probably too low…
  • Edit: Final gravity: 1.012 (means the beer is about 4.3% strong?)

Dreaming about making a measuring device to count bubbles and upload stats to a web page.

Here’s a picture of the Brewmeister brewing:

Brewmeister

Inventortown shut down

I had to upgrade server, so I also removed the online compiler Inventortown. If someone have files there they want back, let me know. I have the old server.

I didn’t actually realize that many people used it, but some people have already requested files off it. The ‘servobot’ project, a very simple and cheap rover/bot that can be made for less than 10 USD-ish, is one project that has been quite popular.

I have therefore written some Energia code that should work ok for the same design. I haven’t actually tested it though, so if someone wants to test it and modify it if necessary, that’d be cool. The file is here.

Finding cheap plastic to mill with the DIY CNC

To test out my CNC, I don’t really want to buy lots of very expensive materials, so I was looking around the house for some plastic. The best thing I found was a plastic cutting board from Ikea, which has been heavily used for many years and can be replaced really cheaply. So here’s a picture of the result, milling an R into the cutting board. The R is about 5cm tall, and I’m quite pleased with the quality. See the middle of the R, where the CAM-processor decided to flatten out the surface (on my request). There is a groove along the side of the R, which may seem like a failure, but that was as programmed by the CAM.

R-milled-in-breadboard

And here’s a screenshot from the control program (ChiliPeppr) of the R and the paths the CNC followed.

R-ChiliPeppr

CNC Upgrade finished

I have finally finished the CNC upgrade. The CNC now has:

  • Improved electronics: GenY32 (this upgrade made a big difference in speed and usability).
  • Improved sliders from drawer-sliders (doesn’t make such a huge difference I think)
  • Improved threaded rods (proper ones made for CNC operations. It now moves much faster)
  • Other control software (Using Chilipeppr, currently with GRBL, but may move to tinyg)
  • New Spindle (I changed from a Dremel-copy to a 300W spindle bought from China. Much quieter and seems to work better)
  • DIY couplings made out of plastic on my lathe and manual router (the rods fell off a few times before I understood how to make them. Hopefully they’re holding tight now).

There is quite a lot of testing left, but at least I’ve made my first foam figure :-) … see the video. Another older video also available shows the build half way done.

DIY Coupling for CNC made in POM

Below is my attempt at making a coupling between the threaded rod and stepper motor in my home-made CNC. The coupling is made in POM-plastic on my lathe and router, and was quite easy to make. It’s basically a 6mm hole in one end and 8mm in the other, with two holes drilled for screws and then a slot routed along the side. The idea was stolen from this commercial Delrin-coupling. It seems to work well, gripping both the stepper and rod tight.

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