Start of mass production

So all of the parts seem to come together, and it is time to start producing more than one of all of the remaining parts.

Note to self: When you change from an 0.8mm head to an 0.4mm head, do not forget to change the infill settings…… I guess these legs are going to break pretty much immediately. Oh well….

In addition to the nice spiral of legs above, I also made a second wheal axel, so now I have two and I should be able to build a creepy-crawler zombie that pulls itself forward on just its front legs…..

No pictures, but the good news is that there was only minimal vibration and I learned how to get super-clean finish by using the driver-thing that moves the cutter head at a constant super-slow speed.

I now also have all of the parts to build the entire chassis, so hopefully pictures will follow….

A little of this and a little of that

Today I went to the makerspace without much of a plan. I knew I wanted to start at least one 3d-print but that was about it.

So I started with printing the rest of the garbage bag holder for the car.

OK. That picture wasn’t great. But it shows that the bed stickyness isn’t perfect everywhere. I will have to ask what to do about that so I can update the documentation.

Since that started without a hitch, I made some updates to the sidewalls of the RHex and printed the remaining pieces needed to build the full robot.

Also here there was some local adhesion problems, but only one part was seriously affected and I think it will work anyways.

Then I cut down the motherboard to size so I can fit it in the robot (Sorry, no picture) and helped out with debugging the distance sensor for the chip evacuator (The signal we wanted was broken, so we could only get the reverse signal which wasn’t very useful). Some additional cleanup of the makerspace including emptying the chip evacuator and then I decided to make a second leg axel.

Unfortunately something wierd happened there. The lathe for some reason started vibrating. It would have worked to make the piece, but inspired by the recent machining adventures of Adam Savage, I decided to try to make the piece with proper finish and proper tolerances. And that was clearly not going to happen today.

Just in case, I purchased a new cutting edge and tried again. The cutter was for aluminum rather than brass, so I also tried to use aluminum. Unfortunately, I got the same result there.

So with that, it was time to go back home. Until next week!

Rounding out the electronics

So over the summer, I have been working a bit at home (No kidding? This is 2020 after all :D). I also purchased a wire wrapping tool at an unbelievable 600SEK for something which is essentially a glorified screwdriver. But it really does its job!

What you see below is perhaps 10% of the wires that the final design will have. Not too pretty, but it clearly does the job. And with some planning, the final design could be really elegant.

So was it just all wiring and smiling faces? Of course not. My multimeter, as well as the identical one at the Makerspace, refuse to measure the forward voltage gap in the optocoupler LED, meaning I had no way of testing that the LED worked or that it was connected the right way. Very frustrating.

But rigging some wires and a resistor allowed me to check that the diode behaved properly and even gave readings on the detector photo transistor.

But when I did the final assembly, nothing at all worked. Since I could not test measure the LED once it was mounted on the proper cabling, it took me almost 2 hours to finally realize that there was a short on my motherboard. I thought I had tested all pins, but there was a tiny lead drop between two of the leg assembly connector pins. It took a full 3 seconds to remove it once I saw it….

Here is me just trying to change all of my assumptions in order to find the error.

But once the short was removed, and I added some black electrical tape to the optobreaker plate since I printed it in transparent PLC, I could finally start my playground code and see the motor starting and stopping with a clear pulse from the optobreaker once every rotation.

It is nice to be awsome!

Now, the next step is to write the regulator code that allows nice clean control of the motor shaft.

I also brought all parts home so I could mount all of the pieces, including the newly printed parts together at home and see if they all fit before next visit.