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 I decided to order all of the parts needed to build the motherboard that connects all of the electronics together. Since I have most of the mechanics, putting the motherboard together will allow me to build a mostly functioning complete prototype, finally.

And here it is, well, not even close to being finished, but at least one dual motor driver and an Arduino can now be attached and removed easily. Also, pin headers for two leg joints, complete with all sensors. Now I just need to do the backplane where I connect all of the pins to each other.

Today I focused mostly on improving things at the makerspace.

Short and friendly signs on the planar and the doors. Better instructions and some helpful arrows on the chip evacuator. And a shelf for the fourth axixs driver for the Terco. That last one was one of the uglyest things I have made in a long time, but for about 10 minutes of work and the joy of using a nail gun for the first time I am fairly pleased.

Today was a bit of a meditative day. I started early with a 3d print to get the rest of the parts I need to build the complete RHex prototype. Unfortunately, I forgot to enable supports, which I noticed a few hours later, so that print had to be restarted.

The good news is that I then remembered to print two toolholders for the late chucks, as well as 2 legs for the RHex. And, then I realized that the Ultimaker Extended + can sing!

So last week, I gave 3d printing a first go. Today, I started a second batch, and could finally assemble the pieces I printed last time.

First up, a refresher on the latest design. As you might be able to see, the chassis now consists of what will be 3d-printed plastic pars reinforced with aluminum tubes. These will connect the bearing houses that will eventually be made from milled Delrin, but for now they are 3d printed as well.

So in order to take a break from CNC, and also learn 3d printing since I will be using that later, I decided to 3d print the plastic parts of the leg joint. Results seem fairly good. The machine had a 0.8mm nozzle so the build is quite rough, but it also makes i stronger which is nice.

Below you see the end result that should allow me to build a complete corner of the robot and see that everything fits.

So since milling tiny internal spaces in aluminum on the Terco without flood coolant seems to not work out, I am redesigning the robot chassis to use Delrin joints with 3d-printed sides reinforced with aluminum tubes.

While I am doing that, I took a detour and did some wood-working that I have been putting off for a while.

Project 1: Serving cutting board

So my first major project at the Makerspace was a cross-grain birch cuting board and I spent more than a month on it. A few months back, I found a piece of cross-grain oak in the “free-to-take” bin. Slightly warped, but OK as a starting point. It was too small to be a primary cutting board (Which is why I assume it was tossed away), but as a serving board it is perfect.

Yeah. So time to test out my dovetail fixture…..

It works amazingly good. Solid, simple and precise. No audible vibrations of any kind. So that was the good news.

The bad news is that the 4th axis apparently was configured to turn the wrong way. So I got something that was not quite a mirror image of my piece. Had it been a perfect mirror image it would have been fine, but alas. One more piece for the garbage bin.

So today’s goal was to make the first leg joint today. That was apparently a bit ambitious, but at least I managed to finish the dovetail vice and prep the first stock.

So this is the last chance I am giving milling for now. If this fails, then I will redesign to use other techniques.

So after last week, I essentially gave up on the 4th axis machining. But when I realized that the problem was the stick-out, together with the fact that the chuck was removable, I realized I could make a replacements part for the chuck that was short and stubby and had a dovetail mount. All good in theory…

So time to mill a dovetail chuck. Got a new 6mm carbide endmill that should supposedly run at 13000rpm and a whooping 1500 mm/min. So that was really scary.