Fixstuff's World: Memorial weekend work

Ok. Another weekend of work. I wasn't happy with the lazy susan bearing design. I don't believe it would have held up, it looked like the bearing would have popped open fairly soon. So I went to a backup design. The profile is not as low, but it will be easier to motorize.

I also re-did the square tubing on the arms. The arms before were too short, and I wouldn't have gotten the full stroke possible. I redid the arms to give me the full stroke on both raising/lowering, and the extension. I ran the motors also, looks like it will work. Not probably good for high speed, high duty cycle, but for what I will be doing it should be ok.

For the enclosures, I joined them in the middle, and cut out an access. This will keep me from having to cable between the boxes, and I like the extra space it gives me. Due to the nature of this being a research platform, I'm going to cut out two square sections on each side and use aluminum tapped butch plates for mounting cable glands, sensors etc. This way, if I want to add or modify something going into or out of the box, I will only have to pull the plate and modify it, and not drill on the box at a later date once it its mounted and wired. I am also going to redo the parts I had mounted to the lid. I am going to use 1/8 aluminum plate instead mounted on standoffs, so that a) the nuts don't stick out of the lid. It looked like crap, and would have leaked water. and b) I can mount the parts, and wire on a bench and then install. This will be easier to maintain. For the enclosures, I found some large rubber shock bumpers that will give me shock absorption.

During the week, I worked a bit on the encoder wheels. This is the non-driven wheels I will have on a third axis in the middle to give me dead reckoning feedback from rover movement. I still have to mount the encoder boxes to the four all-thread rods, but overall it doesn't look to bad. It is a bit weird looking on the rover, and I may need to come up with a spring loading mechanism to let the wheel ride up and down, but well see how this works. I may even step back a bit, and redo the wheels with a same size wheel as the driven wheels. For now, I'll go with this design. If I come up with something better, I may redo it. I'm already thinking of using the same bearings, that I used on the rotation.

Here are also some links to some testing I did of the arm. For the heck of it, I mounted my Gamma 6K detector to the arm, just to see how the coil senses all the metal around it. Pretty damn good results if I must say. Obvious, the mounting won't be like this on the permanent detector. One caveat. I really like how easy it would be IF the detector was mounted this way. I could use different detectors, with an audio cable and just using a preset setup, I could theoretically use the heck out of this as is, without adding anything else other than motor controls. Here are some links to the testing I did with the detector. One really amazing thing. Note the consistency of the audio tones as the coil spins around the rover. Its the same exact sound. Every time. Try to do this with a hand motion with this consistency. It's even better than I hoped for.

overall rotation scanning test