In 1977 George Lucas gave us Star Wars and introduced us to the most famous little droid in the galaxy . . . R2D2. A robot with enough personality to capture the hearts and minds of fans everywhere. Almost instantly it seemed that fans wanted their very own droid, We were no different, and what follows are the builder notes of Dan Thompson as he developed this little 2/3rd scale replica.
This Little Guy Started With A Pipe . . .
I had at my disposal a PVC pipe company in Lubbock, TX, that I picked up 12"diameter 1/8"thick PVC sewer pipe. This pipe would serve as the body of our droid. It provided the correct size and stability we were looking for.
Then We Needed A Dome . . .
As for a Dome, I searched all of the restaurant supply houses for a 12" acrylic cake cover. And was successful, only to find out later that these were the only domes in the country this size and shape, could not find another on the internet anywhere. But it was a near perfect fit. One simply needed to cut off the handle and whala . . . you have yourself a dome!
Well cover more on the dome later, for now lets get back to the body . . .
Time To Plan And Route . . .
The first step to any build is to have a plan. I have downloaded the clubs plans (R2 Builders Club) and took them to KINKO's. Once there I reduced the plans down to the desired size so they would wrap around the 12" pipe. (to get the plans the size we need we multiply the actual dimensions by .666, jokingly making this "The Dark Side Droid." then I used rubber cement to adhere the plans, then clamped a metal strap over the lines of the plans, one by one routing the lines 1/16" deep into the pipe. Using another metal straight edge that was bent to match the curvature of the pipe and clamped it down.
Then I routed the horizontal lines. I used a 3/32" drill bit that I broke off to make the edge sharper and more like a router bit. I had to slide the dremel back and forth along the line a few times to get it all cleaned out. It helps to drill into each end of the line you are working on to give you a feel of were the line ends. This helps because you cant always see it well during the routing process.
When I finished I used a small file on edge to clean out the grooves all over again and again until you feel they are good enough, then do them once more, HAHA. it really pays off in the end.
Once the grooves are done, I needed to route out the door panels. I made a router guide out of mfd board, and affixed it to a couple of plywood ends to make a rotisserie of sorts. I cut 3/4"plywood disks with a 1/4" hole in center and ran a 1/4" all thread rod though the plywood ends and barrel, separating them all with nuts and washers to keep all pieces in place. I have to admit it was tough to keep it steady, so work very slow and watch your lines.
Using a 1/4" drill bit. drill out the corners of the openings of port holes, utility arm holes, door openings, etc. Using a fine tooth jigsaw blade, carefully cut out the openings. ***Note, By grooving the opening lines first before cutting it will allow you to clean them up with a file easer.
Inner Disks And Good Old Lazy Susan . . .
The body requires two sets of disks, one at the top and one at the bottom. For the bottom disk I use a 3/4" plywood piece cut out to fit inside the pipe. I marked the openings for the ports; side vents, and straight side panels. (I made a 1/4" template to use my router cut out these notches in the bottom plywood disk.
At the top of the pipe I cut another 3/4" plywood disk. This one I cut out the center circle to leave a 1-3/4" doughnut. To this I screwed the 12" Rockler lazy susan bearing and dome motor. (More on the Dome motor later)
Don't Leave Home Without Your Skirt!
Again I scaled the plans down by multiplying the dimensions by.666 to make the skirt 2/3rd scale. Using a Photo copier to resize the blueprint, and verify the dimensions. I cut out 1/4" plywood top and bottoms of the skirt. filled in the inside perimeter of the center leg hole and cut some diagonal braces for the styrene shroud to be formed around the outside of the skirt. I added 1/16" thick Masonite strips, and glued to the outside of the styrene shroud for the vertical details.
Having to make multiple R2s for my kids, and Brian wanting so many for The Smugglers Room, I decided to try my hand a vacuforming. Building vacuum box out of 1/4" peg board and wood sides, mounted a intake for my shop vac hose. I added a couple of guide sticks in 3 of the corners to position the frame with the hot styrene sheet. So when I shove the frame and styrene sheet over the form it lines up properly.
First attempts I cut styrene sheet into 18" squares to fit the frame I made. set them into my kitchen oven set at 350 degrees. Watching with the oven light on in the oven, waited for the styrene sheet to show signs of sagging from the heat, when the sheet started to belly out, I pulled it from the oven and immediately shoved it down over the form. Using a paint stick rubbed the creases, corners and details of the styrene to sharpen the form before the plastic completely cools. (sorry folks, the pictures of these are a bit blurry.)
Next I filled the cavity with foam, and presto we have a vacuformed skirt! All that is left to dress this up is to add the Masonite strips, which can easily be glued on. This will add the details to the bottom of the droid. Trim the hole for the center leg and trim the outer edge to the bottom plywood disk. Glue and screw the skirt to the bottom.
I found out on the first pulls the vacuum pulled so well it dimpled the flat part of the panel with 1/4" bumps from the holes in the peg board.
Subsequent panels I cut a couple of 1" holes in the area of where the center leg will eventually go, this seemed to relieve enough suction from the small holes and still get a good form pulled.
Legs To Stand On . . .
I carefully cut out on band saw 1/2" thick MDF board templates of the leg and horse shoe, sanded as close to the leg shape as I possibly could and sealed with a couple of coats of sanding sealer.
Leg pieces were roughly cut from a 8'x5-1/2"x9/16" primed MDF fascia board and a half sheet 2'x4'x1/2" MDF board, using a band saw. The 1/2"thick templates were screwed to the rough cutouts an using my router table setup with a flush cutting bit, roller bearing on the template, I trimmed the rough leg cutouts to exact duplicates for both legs. and saving the templates for more leg assemblies in the future.
The under the horse shoe detail is cut out of 1/8" Masonite hardboard with the rough back sanded smooth, making it about 3/32" when sanded. This horse shoe is cut 1/16" smaller all around of the outside horse shoe, to give it the reveal it needs.
I set up my table saw to cut a dado(groove) 1/4" wide through the center line of the 3/4" piece of the leg in order to have a channel in which to run the motor wires through to the feet. Using my router and a scrap wood guide that was cut to allow the router base to travel along the perimeter cut out. Flipping the router guide over and position on the opposite side of the leg to do the other pocket. I was able to route out the pockets in each of the leg pieces.
I glued a 1/2" leg piece and a 3/4" piece together, aligning all sides and pockets with the help of a screw through the shoulder hub center point clamping them together until dry.
Next step is to cut the groove around the leg to line up with the groove on the boosters. Slip on the ankle bracket and position the booster on the leg, using the groove on the booster as reference, mark the leg and transfer the marks on both sides and top.
Adjust the table saw fence to line up the leg marks to the blade. Set blade height to just touch the leg, then add 1/16" more to set the depth of the groove. Run the legs over the saw blade, then reset the height of the blade again this time to cut the side grooves. Again adding 1/16" beyond the blade touch. the table saw fence should keep the correct distance for you. Keep a good grip on the leg and the guide and verify the position of the cut as you push through the blade.
Shoulder Collar Cut Into Leg
I used 4" Drain/Waste PVC pipe caps for my Shoulder Collars, not to get them mixed up with the schedule 40 end caps which are a lot thicker. These I cut the sides down to 1-1/4" using a band saw, cutting carefully around the circumference of the cap. Sanding and rounding this edge. Find the center of the cap with an adjustable tri square with a center finding attachment, or some other suitable tool.
Using a 1-3/4" hole saw, cut through the newly found center of the cap, deburr and sand. On the leg using a adjustable hole saw cutting tool set to 4-1/2", drill through the shoulder hub center point on the back side (3/4" leg piece) of the Leg. Make a cut into the leg about 1/4"
Cutting The Shoulder Hub Socket Hole
Flip the leg over and using a 2" hole saw, drill through the same shoulder hub center point, ideally using drill press, drill and stop and remove the saw dust, repeating cycles of drilling and cleaning until you have reached the bottom of the hole saws limits which should be about 1-1/4" deep.
Using a screwdriver wedge it into the drill cut and pry out the plug. The MDF board does not have any wood grain and will separate fairly easily. You will then be able to clean up the bottom of the hole using a sharp chisel by scraping across the bottom until even.
A chamfer around the hole is filed to about 1/8" to match the resin shoulder hub piece, use it to guide your actions as NOT TO FILE TOO MUCH.
Ankle and Leg Assembly
The ankle piece are cut out of the 3/4" fascia board also, and glued to the leg below the 12" piece even with the small shelf. A 1/4" thick piece of Masonite is used for the opposite side of the leg to finish out the ankle. rough cut these pieces and after being glued on the leg, use the router table and flush cut them to match the rest of the leg profile.
And next you need to attach the shoulder collar. I have used Galvanized 1-1/4" steel floor flanges screwed to the legs, covered with the 4-1/2" D/W pipe caps. Thread a 1-1/4"X1-1/2" female Adapter to hold the two of them together on the leg.
Locate on the plans, the center point of the shoulder collar, using the same adjustable drill bit. cut a 4-1/2" hole in the side of the body tube. This is a scary part of the build, get it right the first time. Check your center point and check your drill bit diameter, you can always make the hole larger by filing and sanding it, however you cannot make it smaller if you do it wrong. Sorry.
Cut a length of 1-1/2" PVC pipe approximately 10-1/2" long to interconnect the legs thru the body now, these will be pinned later with 1/4" bolts, in order to remove the legs if needed.
Sanding, Paint, and glueing . . .
Give the Legs a good sanding with 220 or a fine grit, a coat of sanding sealer, let dry and sand them again.
Mask off the areas where your other parts are to be glued onto the legs, or as I did you can also scrape the primer and paint off so the glue will stick. Primer and paint to your color of choice.
I used masking tape to outline the small parts on the leg, rather than pencil marks that would have to be removed later, and/or possibly ruin the finish. This would give me guide lines to scrape the paint.
A dome to top it off . . .
I needed a dome to match up with my 12" PVC pipe. I began looking at the local restaurant supply houses for a cake cover. Luckily I found what I was looking for a 12" acrylic dome, and all for $8.50, beats the $300 aluminum spun ones.
In the early days of R2 building I ran across drawings of someone using a metal strap bolted to the top center of the dome and using a Dremel tool to route out or scribe the lines in the dome, I thought this was doable. Two straps are used, one for horizontal lines and one for vertical lines. The vertical strap has two parallel grooves cut out to correspond to the upper pie panel sides. And one groove down below for the lower panel sides.
I reduced the plans of the Dome layout by .666 and placed the dome over the plans and made registration marks on the dome ring to correspond to panel cut out lines on the acrylic dome. 3/32" holes were drilled on a center line of one of the metal strap to correspond to the proper height of the panels. I snapped off a 3/32" drill bit to make a sharp router bit of it, so it would cut a flat bottom in the groove of the acrylic dome. find the center of the top of the dome and drill a small hole to receive a bolt and nut to hold the metal strap tight but not so you cannot swing the strap around the perimeter of the dome. shape the metal strap to the curvature of the dome. The closer to matching the curve the better chances of cutting uniform grooves in the dome.
The hole on the bottom of the strap, is used as a window to align the lines on the dome ring with the center of this hole, that way your drill holes are on center as well.
A 3/4" plywood ring was cut to size to fit tight inside the Dome. Three holes are cut for the Holo eyes in the proper spaces per plans, then a Kitchen sink sprayer hose guide bought from ACE Hardware store is inserted and nut spun on the back inside the dome. The hose guide has a chrome dome of its own and I found a Windex spray bottle cap has just the right scale of grooves to act as the HOLO EYE lens. Cutouts were made for the front and rear logic displays. Roughed out with jigsaw and filed to finished size.