In my previous post, I did a little woodworking on the scale. In this post, I start designing a 3D printed part that will keep the top of the scale centered on the bottom.
Ever since I measured the center of gravity of the top plywood circle, I’ve been puzzling through how to make sure that center of gravity stays centered on the bottom part of the scale. Without some sort of connection between the top and bottom plywood circles, the top will inevitably slide over time, messing up all the center of gravity calculations. On the other hand, if this connection between the top and bottom has much vertical friction, it will take some of the load of the scale, throwing off the weight calculation.
Continue reading Dog Weight Scale Part 12: More 3D Printing
In my previous post I described how to calibrate a load sensor. This post shows how to measure center of gravity, and shows a failed attempt to mount the load sensors to the scale.
Now that I’m using 4 load cell amplifiers rather than 1, I can calibrate each load sensor separately. This in turn will let the Arduino calculate Pippa’s real weight accurately regardless of what part of her bed/scale she’s lying on.
Continue reading Dog Weight Scale Part 5: Center of Gravity and a Mounting Fail
In an earlier post I tuned the chimes. In this post, I find one way not to make a frame for those chimes.
I created the frame for the glockenspiel, with a square frame on the outside so that I could mark the inner part of the frame with 1″ lines, one per chime.
Continue reading If at First You Don’t Succeed…