I'm just talkin' bout Shaft

Work commenced again yesterday towards final assembly. The NPC motors come with a shaft on both sides, one of which needs to be cut off to allow the Battery Boxes to fit over them. I failed to take a good pic of the motors with the extended shafts still on the droid, but they can be seen here with the motors attached to the JAG foot drives:

At first I tried cutting the shafts with a metal blade on a chop/miter saw. It cut fine but was only able to get close enough to end up leaving about a half inch of the shaft still on the motor. It also made the shaft extremely hot, which probably wouldn't damage the motor, but I didn't want to take that chance again. Since something else was needed to finish the job I decided to just use a hacksaw. With it, there was no problem getting extremely close to the shaft housing. It only took a few minutes to trim off the remainder of the shaft, then a couple metal files were used to clean up and smooth out the finished product.

The same process was repeated on the other motor shaft, minus the chop saw. Fairly quick and easy. Definitely easier with two people so that one can hold the motor while the other saws. Now onto getting the Battery Boxes to fit. That requires grinding the tops of the motors, and a cut or two to each box as well.

Must be Italian.

I finally re-kickstarted my build a couple months ago after about a year hiatus of working on R2 and staying off the astromech boards. One of the first things I did was buy a new/second dome. I knew my 300mm dome was going to cause me some headache down the road, even after all the hours of work I spent painting and sanding. Now that I'm further down that journey I decided to ditch the old dome and get one of the new Hydro formed domes. These are made out of a different aluminum with a completely different forming process, hopefully eliminating most of the issues with the older style domes. They also have almost everything pre-lasercut. Mine came in a few weeks ago, but I was in the middle of getting all my electronics up and running that I never posted pics. So here you go.

I also splurged and got the new Ultimate Hinges for 11 of the dome panels. A new electronics portion of this solution is coming soon. Its hard not to want all the bells and whistles of R2, even when yours isn't quite "finished".

One small roll...

Here's a video of R2 rolling for the first time after over a week of wiring, crimping and cutting. Long, long time in the making.

Holy sheets!

A few other things needed to be done before I could get Artoo up and running. I needed to decide how to run wires through the legs, and I needed to fix the center ankle locks.

After even more debate (sometime I swear I spend hours just looking at something before breaking down and doing it), I decided to drill holes in the underside of the ankles. Most builders do this, there's only a few that have wires routed differently and hidden all together. I figure they are so low to the ground, someone would have to get on all fours to see the wires come out the ankles. This was pretty easy, just measure and mark the spot on the ankles, and use a drill press to get a nice smooth hole. Later I took a small file and sandpaper to de-bur any slag. I also put a teeny tiny angle on the inside wall of the holes. That way there is less of a sharp edge to wear down the protective wrap of the wires and it should help prevent any shorting down the road.

Always a little stressing drilling or cutting into something very expensive. I'll probably drill a hole into the battery boxes when I get further along. A lot of builders drill the second hole into the top of the foot right below the ankle. Neither is better than the other, its all personal preference. I figure the battery boxes cost a lot less to replace if I screw it up.

Back when I installed the center ankle locks I noticed there was a bit of a gap left below the locks themselves. This caused a tiny bit of rocking in the center ankle when changing direction. So I knew I had to fix it. I had some aluminum sheeting laying around that I plan on using for the kick plates and behind the utility arms. Test fitting the sheeting looked like it would be just the right thickness. I took the locks off, laid them on the sheeting, drew a line where I needed to cut and broke out some cutting shears. I bent them back out as straight as I could and then used some fast setting epoxy to adhere them to the locks. A little sandpaper and elbow grease evened out the transition between them. I slapped them back on the center ankle and viola, a stable ankle that no longer rocks.

I will cut you

Lots of work has been going on, and I'm finally sitting down to author a post about it. I've spent the last month testing and assembling the electronics side of Artoo. About a month ago I traveled down to OKC for a Saturday to hang out with fellow R2 builder Patrick Yeary. He helped me test wire all my electronics, and by the end of the day I had remote controlled motors rolling just like they should. It really helped having the knowledge of someone that had already done it, along with a working R2 sitting there to look at. I'm still an electronics noob, but I'm slowly becoming more of a novice. Things now make sense about 30% of the time instead of 3%.

So once I had everything test wired I knew I needed to do a few things to get my actual wiring ready to go. First up was figuring out where my switches would go. The Com8-B frame is great. Its fairly economical for an aluminum frame, its club spec and has been well engineered. That said, it has a few shortcomings because of its budget nature. There's no real good place to put switches on the frame, it only has two small electronics plates on either side of the body and the holes in the middle body plate are pretty much a terrible place for the speakers. All this needed to be addressed at this point in my build. 

I looked around at various places online to find more plastic sheets to use as electronics boards. I ordered some off Amazon but it felt too flimsy to mount anything of weight on. So I went the tried and true method of using store bought kitchen cutting boards. Target had a nice three pack on sale for less than $10 bucks. Lucky they were so cheap because I actually screwed up my first attempt at a switch plate. They are also fairly easy to cut thanks to my dad's table saw.

I didn't want to drill my frame at all if I could avoid it. So after great deliberation I decided to put the switches between the bottom and middle ring of the frame where they will be easily accessible behind the rear door. I bought some switches from Walmart and splurged on a Hella switch for my main power on - I liked that it requires a key. I laid out the holes in Illustrator and made a template to use on the drill press so that everything looked nice and even. We cut one of the boards to size and then drilled out the holes for each switch (Hella master switch, two 35 Amp switches for each NPC motor, one 20 amp switch for the dome motor, and two more 20 amp switches for use in the future). I also drilled four small holes in each corner where I will use zip ties to attach the plate to the frame.

Next I decided to make my own speaker plate for mounting the speakers behind the Center Vents. Most builders use this area for speaker placement, and it just makes the most sense - way more than inside the body where the sound would be muffled behind the skins. This was fairly easy to do. I cut one of the plastic cutting boards to size (5x8), placed the paper template for each speaker on the board and then looked at them behind the Center Vents to get final placement.

I lined up the plastic board with the vertical pieces of the frame and clamped it into place. Then I drilled four holes through the board and into the frame. Next I tapped the frame holes for 6-32 screws. I accidentally broke my tap in the first hole and had to run to Lowes for a new one. I couldn't get the broken tap out of the frame and ended up having to sand it down and flip that piece of the frame to re-drill the hole. It wasn't my finest hour, but its nothing that will ever be seen and will actually be a nice identification piece to my droid should the need arise. After all the holes were tapped I used 1.5 inch screws and 1 inch nylon standoffs to attach the board to the frame.

Next up I broke out the biggest drill bit I had and put a hole on one side of each speaker template hole. I then used my grandpa's old jigsaw to slowly cut the remainder of the holes in the board. The plastic cut like butter and in the end I had my own homemade speaker plate.

The final piece of the cutting board fit quite nicely behind the new speaker plate so I decided to use the entire thing as a good sized third electronics plate. I basically went through the same motions of clamping the boards together, drilling four holes and using long screws with 2.25 inches of standoffs to separate the two with room for the speakers.

In the end it all tuned out quite nice and I now have over double the area to mount electronics inside the body, all with only drilling four small holes into the frame.

Like a glove, a power glove

The two main batteries have arrived. There was really sticky tape on them that is near impossible to get off. Already took off some of the paint trying to get them de-stickyfied.

And here they are in their new home. Perfect fit.

Also logged in to the astromech forums today for the first time in probably a year. Already contemplating a while new dome and hinge set. That's why I've stayed off them for this long!

Get Your Motor Running

Its happening. NPC motors, Sabertooth and Syren 10 motor controllers have arrived.