Someone recently asked how much I trimmed off my utility arms to get them to fit thru the skins. Here’s a quick photo. It maybe a little more than is needed, especially if you have resin arms which tend to be smaller – but once you add on a few layers of paint it was about right. It’s also very important that there’s no sag in the arms as they open up. I can guarantee you’ll have issue if there is.
I’m still fiddling with the periscope, I added some LEDs, a servo to make it turn and something to mount it to the lift mechanism.
But first I had to adjust the dome pie panel cut out to give more clearance. I marked off the area I wanted to cut and Dremeled in a few slots to start things off and finished it with a small hacksaw blade.
The main periscope assemble is mounted atop PVC tube to add more height.
I wanted to easily remove it for maintenance and also allow some height adjustment at the same time. This little tube is fixed to the lift mech
And the main PVC riser tube slips over and locks into place with a couple of screws
I installed a small HiTec HS-55 servo into the top of the PVC tube to turn the periscope side to side when it’s extended. Attached is a round plate the aluminum based of the periscope will screw into.
I’ve also add the LEDs to the main periscope housing. On the front is an array of 6 rectangular LEDs. These are very close to one’s used on the original ROTJ periscope
They’re glowing orange in the photo but they’re deep red in person. Power is 12V and no resistors needed as they’re in series
Here’s the block of LEDs soldered together before I installed them
I’ve wired in some bright white LEDs inside and some colored one’s on the back of the housing, I also re-appropriated one of my old PSI boards to blink a couple of LEDs to add a bit of variety.
Getting closer 🙂
I finally got a chance to fully test out my slip ring last night with some servos.
I first had to finish soldering up my little boards that would handle signal routing and power.
Rather than try and explain in words and pictures how the setup works I made this short video to try and give a good overview and show the slip ring in action.
I still need to make little brackets to secure the D sockets to the boards, and decide the best place to locate them in Artoo.
I cut the hole for the slip ring tonight.
Started off by marking the center lines and then using a hole cutter to score the 7/8″ outline where the slip ring body would sit.
I then marked off and drilled holes where the slot would go for the cable plug to pass through
I used a Dremel and a hand saw to join the holes up
You can still just see the outline of the circle I’d marked
I then took a file and made the small circle notches either side of the slot to accommodate the slip ring
Testing that ring slip ring fit and that the plug will pass through
Top view of the slip ring secured in place
Now to solder up the connectors
It’s funny, I’ve been working on the new astromech.net website and DroidWiki all week and today used it myself for the first time to look something up.
Sadly I came up blank, but I don’t think it’s the fault of the wiki, but our part naming standards. I don’t think the blue surround that goes around the front vent surrounds has an official name. It’s kinda weird calling it the surrounds surround, but that’s what it is 🙂
My droids skins are removable, and the vents are attached to the inner-frame somewhat permanently. Getting the skins on and off with the blue surround permanently attached to the skins would be tricky, so I decided to kept the blue piece separate and use some magnets to hold it in place. I’m sure I saw the idea on someone else’s website, so I can’t take credit for it.
I carefully marked the optimum spot and glued the magnets on with epoxy
Using some tin snips I put some thin steel and made little tabs that would attached to the skins and allow the magnets to hold on
I attached them to the skins using CA glue
Here you can see the tabs just poking around the vent
And the blue surround in place
It’s not a perfect solution, and I’m a little worried it may pull off to easy. The tabs are also made from pretty thin steel, so the magnets don’t have a lot to attract to. At some point I’ll probably go back and add some thicker steel behind each to help the magnets grip better.
I could trim the surround a little and glue it permanently to the skins, but getting the skins on is hard enough and I’m not sure I want to take too remove that much material and like the tight fit.
This is another retroactive post on something I worked on sometime ago.
I wanted avoid permanently attaching the side vents to the skins to allow more flexibility, but it’s not as easy as just making a simple bracket and screwing it to something like you could on a wooden frame.
I’d experimented with a few different methods but wasn’t happy with any of them, and I was convinced I’d end up using silicon to stick the vents to the skins permanently.
But at the last minute I gave this idea a shot – I tried attaching an aluminum plate to the back of the vents and hoped that a combination of sandwiching them between the opening in the skins and the pressure from the new aluminum plate from the inside would hold everything in place.
I took some of the same aluminum sheet I used for the side panels.
And cut squares that were slightly bigger than the vents and bent them to roughly the same curvature of the body.
This a shot of the new plate from the inside of the frame covering the side vent hole
I then used silicon to attach the plate to the backside of the vents
Then it was just a matter of waiting for the silicon to dry and wedging them between the skins.
It’s funny, the side panels are one of the few things you’ll not see discussed often on the Y! Group or on builders blogs. I’m not really sure why. My theory is that most likely this is the last thing that you work on before rushing off with your new droid for the first time – and sadly overlooked when sharing building tips.
What exactly are the side panels, well they’re the small nondescript flat square pieces that fill the holes below the side vents. They’re typically not included with frame or skin part run, unless you’re using a fiberglass body. So material and implementation is left up to each builder to figure out.
Here’s a shot of the side panel on the the ILM Uber R2 – which incidentally has them molded into the skins.
I’m guilty as most builders and left this part to the last minute – but thought I’d do my duty and share the solution I came up. At the time I thought it would be a temporary fix, but most likely it’ll stay this way for a while.
The plan was to cut the panels out of aluminum and attach them to the frame using the same bolts that attach the skin mounting blocks to the frame. Here’s a good shot of a skin mounting block.
I started off by cutting some spare aluminum sheet to fit in the gap.
I cut it slightly too long as I wanted to bend it over and create an L shape. Don’t ask how wide the plate is – I made it to fit snug in the groove in the lower ring of my aluminum frame, and in this photo it extend all the the way down and touches the frame ring where the mount block is attached.
I cut a few notches from the corners as it needed to fit around the frame vertical supports.
I then bent it along the line I’d marked earlier, making an L shape
I marked and drilling the mounting holes
Then test fitted and tweaked the edge until it was flush with the skirt and skins
I added a couple of quick coats of paint using the same formula as the skins (metal etching primer, gray primer Rusoleum satin white)
Here’s the final version of the panel bolted to the frame ring and skin mounting block
I’m pretty happy how it came out, and it’s one of those parts that nobody really pays much attention to anyway.
However, one of the issue with the panels sharing the same bolt with the skin mounting block is that when putting on the skins I find it easy to get them to fit by keeping the mounting blocks little loose. But once the skins and panel are in place it’s incredibly hard to then get inside to tighten the screw up to hold the side panel firmly in place. It’s hard to explain, but trust me even with small hands it’s really difficult to juggle the skins, side panels and mounting blocks to get everything tight and aligned.
Now that WonderCon is over I’m hoping to go back and post details on the final few steps of my build – I’m probably going to post some things out of order, so you may see some things in the photos that I’ve not covered yet.
First up is the the rear panel/back door. I’d deliberated this for a while and tests a few different methods before finally settling on using the rare earth magnets.
I’d bought a bunch of different sizes, with the intent of using them on various spots on the droid.
One of my fears was the smaller magnets wouldn’t hold, and if I’d went with the larger magnets they’d get in the way of my movable electronics panel, or the door would be impossible to remove.
Frank Cerney had posted a few months ago about using 1/2 inch cylindrical magnets (NSN0818) from Magcraft successfully to hold the door on a wooden frame, so I decided to do something similar. Here’s Frank’s original implementation –
I don’t have the luxury of being able to drill holes in a wooden frame, so I needed to come up with something to hold the magnets to the skin. On hindsight maybe I should have gone with square or block magnets instead, but I was stuck with what I had on hand.
After a few experiments I ended up cutting some aluminum U channel into 1 inch chunks and bent them to clamp the magnets.
The gap is slightly narrower than the magnet, and I simply tapped the magnet in making sure they matched the opposite one.
I then took my CA glue and excellerant and glued them to the skins
I could have used epoxy, but I really wanted this to setup quick without worrying about clamps, movement etc. It seems to hold okay, but I still may still go back and re-enforce them with some epoxy at some point.
Here’s the skins/frame assembled showing the final location of the magnets
One of the issue of using the magnets to hold the door on from the sides is that the force pulls outward, instead of pulling or holding the door tight toward the frame/skin, like if I’d used screws to hold it in place.
You probably can’t tell from the photo, but this results in the door,which naturally curves a little tighter than frame, to bow out at the top.
To combat this I added a tab which will pull everything together and hopefully add a little more hold and reduce the strain on the magnets.
Again I used CA glue to hold it in place
I topped everything off by added some white tape to the inside line of the skins.
Remember I’d had a problem closing the gap at the bottom of the door once I’d cut it from the skins, so rather than fight with it – I simply masked the problem by covering the raw aluminum which blended the door into the skin. I have to thank my wife for this suggestion.
Due to the electronics panel having to swing out I had to either attach the rear power coupler to the door or make it removable from the frame. I opted for the latter as I didn’t want additional weight on the door.
I simply cut a chunk of metal (not aluminum) and secured it to the back of the power coupler. I then used a large magnet on a bracket on the frame to secure the power coupler and allow me to pull it off when needed
The good news is the door holds on great and I had zero problems with it at WonderCon – it even held on even when I did the R2 death spin 🙂