R2Droid.Com

It's finally time to finish up the legs. I have all the pieces and they are fitting together nicely. The motors are running smooth....it's time to paint!! Almost all of the pieces are aluminum except for his feet which are steel. The steel will handle more of a beating. The steel pieces need and extra primer coat of self-etching primer, to help stop the rust. There is a good article about what it does HERE. I had already put it on when i got the feet, but they have taken a beaten during the building process so I decided to sand them down and do them again, fresh while everything else was getting primed.
Here's the Self-etching Primer I used.


Here are the steel parts after they have had the self-etching primer put on them. It's a pretty ugly color.

Then after breaking down all the aluminum pieces, I cleaned them all up with some steel wool and did whatever masking I had to do with 3M tape. I didn't take any really clear pictures of it, but you can kind of see the pin stripe of masking tape I used to make the line that runs around the lower half of the main leg section and is also etched into the booster covers. I hated breaking the legs apart after getting them together finally...


I used Krylon White Primer to prime everything. I used Rust-oleum Satin White Sku#7791 for the actual R2 white on all the parts.

Put Simply the booster covers were a pain in the ass! I have aluminum booster covers so I really wanted to mask out the silver parts, not paint them after. It took me two tries. The first time I masked the boosters totally with tape and they looked like junk after, no straight lines. It was a pain to sand them back down, but I did. The second time around I used a combination of tape and liquid latex, a tip I learned from Chris James Site. There are 3 sections that need to get masked. The 4 stripes at the bottom, which I used tape on, the pinstripe line that runs around the booster , which I used latex on, and the two roundish square holes cut into the top piece, which I also used latex on. The latex just paints on, then dries and can be peeled off easily after painting. Because of the clearcoat that goes on the Blue Pieces I used an exacto Knife to first cutout the shapes then peel the latex. Here is a cover after I masked it...


Here is the latex I used, I found it at my local Michael's craft store.

Then They got Primed...


The Blue Pieces on the legs all got painted using the same Krider Blue Method I used on the dome pieces, which I outlined in an earlier POST. Here are the Paints...

Here are the Boosters after they were done, they look much better in person, the clearcoat gives the pictures too many glares and the lines look warbly, but they are not.


When the Boosters were attached they lined up nice with the pinstripe I added to the legs. The tape worked great, I am very happy with the results rather than having to actually cut into the aluminum.

Here is the Middle leg all done, I used epoxy to attach the aluminum strips, and I used the red thread lock stuff to help attach detail pieces that I didn't want to come loose. I didn't use it on everything, just the pieces I knew would (hopefully) never need to come off.


Here's an outer foot all done

Here They are all done...

Now that the Outer and Middle legs are done it is time to finish the battery boxes so these babies can get painted. My boxes are aluminum, I first tried out some PVC boxes but the thickness of the plastic made it impossible for the Battery boxes to fit over the NPC motors I am using on my JAG foot drives. The Aluminum Boxes have removable back plates and cutouts for the motors. However the cutouts aren't quite big enough for the NPC's, so the first thing I had to do was enlarge the opening on the bottom. This picture shows the bottom of the boxes, the one on the left has been modified, the one on the right is how it was originally cut.


I also added two threaded holes to the bottom of the boxes so they can be screwed on tight to the feet. Again, in this picture the left box has been modified with the extra motor cutout and the two threaded holes, the box on the right has been untouched.

Next I added a hole to the side of the battery boxes that faces the inside of the outer legs, this hole allows the wires to pass from the legs to the motors in the feet. I know there are a lot of different methods for getting these wires to the feet, what I did was simple. The holes in the legs and the holes on the battery boxes line up across from one another and there is only about 1cm of wire visible, but you really have to look hard to see them. Now that it is done I am very happy with how it came out, the wires are pretty much invisible once all the legs are together. I also added a rubber grommet to the hole so the sharp edges of the metal wont cut into the wires.


This next picture is from underneath the feet. The boxes are attached and you can see the heads of the two screws I used to tighten the boxes on, they are on each side of the motor cutouts.

I also used nuts on the two screws to really tighten them down, I figure the feet and battery boxes get a lot of the vibration from rolling around so they really need to be on there well. This picture is looking straight down into the back of the battery boxes and you can see one of the nuts in there.


The next thing to do was grind down the tops of the NPC motors. They almost fit into the boxes, but because the boxes are round on top and the motors have a flat squarish top they had to be ground down. Here's a before and after:

Before


After

Next it was time to add the battery straps.


I drilled and threaded a hole on each battery strap, under where the blue button would go, so you wont see any screws.

I did the same on the battery boxes.


The straps get screwed on from inside the battery boxes. You can see the screws here.

Here they are attached, they are on very tight. There are two small pieces that go on the bottom of the straps. First I painted the boxes then attached the pieces using epoxy.

Well, once again it's been a long time since I have updated this site, but I have been spending my time building R2 rather than updating the site. I will get all caught up from here on in. After finishing the Middle leg I decided to focus on the Outer legs. I have all pieces for them now I just have to get them all to attach to one another so they can be painted. Besides some of the detail pieces all my leg parts came from JAG, www.R2-R9.com, the first thing I had to do was counter sink the screws that attach the outer leg to the outer ankle - shown here:


Here are the holes after I countersunk them, above the ankle you can see the spacer plate that goes in between the leg and ankle to get the right lip for the ankle bracelet.

Here they are attached and smooth with the ankles.


Next I had to make the hole at the bottom of the ankle to allow the wires to pass to the motors, I know there are a lot of different methods on how to pass your wires from the legs to the feet, but I went with a simple idea of a hole at the bottom of the ankles that lines up with a hole on the side of the battery boxes. Not totally invisible but I can say now that it's done that you have to look really hard to see the wires, really not noticeable. Here's the hole at the bottom of the ankles:

Next I had to drill two holes to add the under the shoulder detail pieces, here are the markings for them:


When I drilled the holes I drilled them at the same angle the "arms" of the detail pieces so they would go in smooth, which make the holes slightly oval-ish:

Here they are installed:


Next I added ankle locks, I am mainly keeping my droid in the 3 legged position, so I used these ankle locks to make him more rigid while driving and I can just unscrew them if I want to put him on 2 legs. Here are the pieces and the hole I drilled and tapped on the ankle to attach it:

Here is the ankle lock attached:


Here are the shoulder hubs I got from Russ at www.rbreplicas.com, they have 3 magnets inserted in the backs of them.

I used epoxy to attach 3 magnets inside the legs to attach the hubs, the magnets are strong and now I can easily have access to the inside of the legs.


Here are the hubs installed:

I had to drill a hole in the shoulders to allow the leg wires to pass into the body, I had to offset it so it would not interfere with the shoulder hubs as seen here:


Here are the shoulder horseshoes with all their details attached:

Here is a leg completed, ready to be painted. I do love the aluminum look though. All the other details like the booster covers, leg struts and ankle details all simply screwed into the holes provided by JAG when I got the leg pieces.

Well after taking the winter off from droid building to finish some other projects it's officially time to get back to work. Right now R2's dome looks done from the exterior and all his lights work, but I still have a lot to do inside to get his gadgets working. His body will be the last thing to finish. So now I am going to finish the legs so I can concentrate on the electronics and body for awhile. Starting with the middle leg. The first thing I wanted to do was add a layer of rubber to the caster mounting plate for a little shock absorption. The method I am using I saw on someone else's site but I can't remember whose for the life of me, and it definitely is the cheapest of all the solutions. You basically take a rubber plumbing pipe connector and cut it to size.

This is the one I got.


After cutting it to size, the next thing was to cut four holes that match the caster plate. The rubber layer sits in between the standoffs and the caster plate.






Pretty straight forward, It might not do a lot but hopefully it adds a little something. I am not gonna be taking him out on parades or anything extreme.

The next thing was to work on extending the skirt on the middle leg. My middle foot is a steel JAG foot from a run that happened before the bottom skirt matched the outer feet. After spending so much on so many other parts I really wanted to make this foot skirt extremely cheap, it didn't matter if it was 100% accurate I just wanted to get something on there that looked good and could take a beating while bumping into things. I knew I wanted it to be metal so I bought some right angled Aluminum that was 1/16th of an inch thick and 3/4 of an inch wide. Like this: So I figured out the angles as best I could and started cutting some pieces... After I had the four sides I made the cutouts for the caster wheels to swing through. Then I took some JB Weld and filled in the seems and also used it to attach the skirt to the foot. I put the JB Weld on in layers and used my Dremel with a sanding attachment to smooth it out, then finally some fine grit sand paper to finish it off by hand.

Here it is all done with a coat of primer on it. All in all I am very happy with it and it probably cost me about $10 to make. It is slightly wider than what it should be, but I think it looks fine.

The Last thing the middle leg needed before it could get painted was it's ankle locks. These prevent the foot from tipping in the wrong direction while he is driving around. All I had to do is drill and tap 2 holes in the ankle to attach them. Like so:

So I moved a few months ago and it has been hard to keep this site updated but I have done a lot on R2 and I hope to keep the site updated again. I have also been busy collecting all the aluminum detail pieces for R2 and I am done! I still need to get internal electronics and hardware, but I have all his external detail now...


Ever since I finished building his legs with all their various wheels and motor drives I have been dying to get R2 rolling, especially since I still had the satellite motors in the shoulders, I have heard horror stories about them failing people. It was time to start wiring up this heap of electronics I had collected over the last year and a half. I am not an idiot when it comes to this stuff but I am definitely not a pro by and sorts. I was very nervous about wiring up something wrong and burning a component out. A big thanks goes out to Chris James for answering a bunch of last minute questions for me. I basically bought the best stuff I could on my budget. I went with some Vex stuff for now knowing I would probably swap it out way down the line when I needed more channels on my transmitter for his internal gadgets when I get to them. Also the VEX stuff is much cheaper than say Futaba. When it came to motor controllers I went with Dimension Engineering. It was down to them and Vantec, I know Vantec is a very popular choice among other builders but I also had heard about the famous Vantec whine and they were quite expensive. The Dimension controllers specs said they could handle what I needed and they were significantly cheaper. I went with the SyRen 25 for the dome and teh Sabertooth 2X25 for the feet.

Here is the Vex Transmitter and Receiver I got new on eBay for $26.00


Here is the Vex Micro-Controller, this sends the commands from the from the receiver to the motor controller

Here is the SyRen 25 Motor Controller for the dome motor


Here is the Sabertooth 2X25 Motor controller for the feet

I used one of Dan Stuettgen power distribution boards to power my various electronics except the feet. It takes 12v in and gives you some. 5v, 9v, and multiple 12v outputs.


When I initially powered up the dome I felt the 12v was a bit too slow for it. The motor i am using, a Pittman motor, model GM9413-2 can take 12v to 24v. So I ordered a 12v step-up converter to give it a bit more juice. It has a variable output trim so I set it for about 20v and the dome is spinning perfectly. I ordered it off of eBay for about $15.00

I ordered 2 Rhino 12v SLA (sealed lead acid) 18ah batteries. One for the feet and one for everything else.


I also installed a voltage display with a 3-way toggle switch so I can monitor either battery's voltage.

After I got it all wired up , surprisingly it all worked. I had to make some adjustments with the feet and legs to get him rolling straight. After watching him roll around a bit I have decided that there is too much play in the shoulder motors. I want to get rid of the shoulder motors and attach the legs more securely. Looks like he will be a fixed 3-legged droid, but i will trade the 2 legged mode for a more secure droid while he is rolling around. The motor controllers are silent and boy does he have some power behind him. All in all his first steps were a success, I do have to redesign the shoulders but at least all the electronics work! I iwll be posting a more detailed diagram of how he is wired up soon.


Here is a video of R2's first steps and his electronics....