Tonight I’ve started to work on some dome stuff, including the dome drive system which has been bugging me for months.

I’m using Darren’s dome drive kit (based on Atomic Pickle’s) and it uses the Pittman GM9413-2 geared motor. Spec’d at 12v, 19.7:1, 142RPM.

To me it seems sluggish and rotates slowly compared to a lot of other droids I’ve seen, especially when I change direction. It could be the weight of the dome, which is around 17lb with all the accessories. Including all alu parts, like HP’s, surrounds, radar eye, dome ring, and periscope, plus the batteries, smoke/fire-extinguisher etc. etc. But I’m sure I’m not the only one with a heavy dome.

I’m wondering if others are experiences sluggish domes who are using this Pittman either from Darren’s kit or from AP’s? Especially if your dome is heavy?

According to the GM9413-2 data sheet on the AP site, the motor is rated at 12v, which is what I’ve been running it at, but on the motor itself the label says 12/24v.

I’d rather not run it as 24v if I can help it – but if it would help I could re-configure some of my batteries as a last resort.

The only other thing I can think of is the slight sagging in the mounting, but the motor is making full contact with the rockler bearing. Maybe it’s not doing a great job of holding on or maybe pushing too hard against the rockler bearing?

I know many Sennaites are using the Saturn motors at 24v for the dome, but I’d rather not switch class of motors right now. I’ve posted to the Yahoo! Group to see if anyone has some suggestions specific to the Pittman motors.

Edited to add some videos. Here’s the Pittman running at 12v directly off a battery, no speed controller so startup is instant and it looks okay right now which I don’t understand. I’m wondering if it’s a speed controller issue, or maybe even a problem when he’s angled in 3 legged mode. mmm.

And here it is running at 24v – super fast I know, but I’d rather the top speed be fast and I can slow it down with the transmitter/speed controller commands.

Now to troubleshoot why the 12v spin seems okay.

I did some further testing tonight, and held the body at an angle while the dome spun. Man, is there a lot of force whipping around while it turns, even at the slower 12v. I can feel it struggle on the up swing as the two heavier side of the dome comes around. 24v helped a lot but I need to go back and put the speed controller back in the loop to confirm my test and see how snappy it is looking left and right.

More re-assembling tonight after painting last week. I did a mix of things from the feet to working on some skin panels.

I got the feet and ankles back together, and using the hex bolts worked out great. It was a breeze installing the ankle details.

With everything R2, there’s always a few steps back with a dozen forward. Today it was the braided hoses. I’d planned on using these expanding rubber plugs to hold the cables in place, but they didn’t quite work as I’d hoped. For some reason rather than bunching up and expanding the nut inside just moved/ripped up the rubber with minimum expansion as shown. The ‘bulge’ at the top being the maximum width.

Back to the drawing board and Ace Hardware tomorrow to look for an alternative. I was tempted to try Douglas Olson’s KHF System again, but space is very tight and they’ll not work for me with the JAG feet and drive system.

The other problem I had was once I tried to install the battery boxes they wouldn’t fit over the NPC motors. All the test fittings I did while filing down the tops of the motors was done without the ankle on the foot, so now I have less room to bend the box over and down onto the motors. An easy fix, but I was hoping to get the feet, ankles and legs back together tonight and now I can’t.

I also worked a little bit more on the frame and got the front vents installed and attached to the frame at last. Not sure how I’m going to fix in the blue surround at this point. Maybe silicon, but I want to be able to remove it easily with the skins. The fit is tight and I can see when removing the skins that it may get pulled off with little effort.

I’ve started to peel away the masking on the skins over the weekend and mounting the various body detail pieces.

I even temporarily mounted a door to see how well the hinges work.

Overall, I’m very happy with the finish and how the aluminum shows through from the inner skin layer. The only real clean up I had to do was on some of the green self etching primer that had leaked underneath the tape, but it was easy to remove with some acetone and a q-tip. I did spot one place on the rear skin that I may sand down and give it one more coat.

I also started to mount the detail pieces to the skin and frame. For the octagon ports and power couplers I plan on permanently attaching them to the frame and have the skins press up against them.

I took some 1″ x 1/16″ alu stock bar and made some slotted L brackets. The aluminum is easily bent in a vice.

I ended up elongated the holes to make them adjustable.

A lot has happened in the last month with a bunch of posts to the blog . I thought it maybe a good idea to summaries the last 30 days for easy reference.

• 12 Channel RF Remote Notes
• Re-assembling the Bits – finally getting things back together after painting
• Skin Update – gluing skins, drilling and mounting to frame, priming and first top coat
• Unwrapping Blue Bits – lets see how those blue pieces turned out
• Holiday Weekend Update – lots of work from gluing skins to painting
• Knurled Hose Fittings
• Cutting Skins and Rear Door
• More Painting – masking difficult parts and painting hypo blue, and more
• Laying Out Skirt Ribs
• Cutting Out Skins Quickly – another quick tip that will save you hours
• Quick Tip – Right Bolts for the Job
• Under Shoulder Detail
• R-Series – Volume 3 Now Out
• R2 Garage Buddy – nice tip on what 3D model to keep handy in the workshop
• Dome Switches – rethinking the dome bump switches
• NPC Battery Box Cut Out Template
• From Feet to Painting – lots of work this weekend: KHF, Battery Boxes, NPC Motors, Hoses
• Halloween 2007 at Hiller Aviation
• R2 Builders in new SW Vault Book

There was some discussion on the builders message board recently about reprogramming the unique encoding on the newer 12 channel RF remotes.

Much of the documentation and notes on various R2 sites are for the older remotes. I thought it might be a good idea to document my findings on the new remotes.

I don’t want to repeat in detail why or how R2 builders use these boards, but the most common is to trigger sounds in your droid when combined with a CF3 sound system. Most of what’s been written about integrating the board into your droid applies no matter which revision you have – but changing the encoding has.

First up, most people find these boards on ebay. Just search on “12 rf remote” and you’ll find a lot of sellers offering them from all over the world. Don’t pay more than $30-40 with shipping. There’s still a few sellers offering the older boards too.

So what’s the difference between them? Not a lot to be honest. The newer boards are easier to reprogram the unique identifying code, and the transmitter is a little smaller. However the new receiver board does have an annoying buzzer that needs disabling.

For the geek in you – On the receiver board, auto learning decoding scheme has been programmed into the MCU IC chip, and inside the remote control or transmitter there’s an Encoding IC Chip, an SC-2262. This set of IC chips can be used to encode your signals so that multiple remotes in close proximity will not interfere with each other. In theory you can pick from 6561 different combinations.

Do you need to worry about changing the code? That’s easy, most boards are shipped with the same factory default code, and you don’t want your droid to clash with some else’s.

For reference, here’s the older board and the remote which is somewhat larger

If you have one of these then jump over to Alex’s original RF remote tutorial.

Warning: The Positive/Negative terminals are swapped on the new and old boards. Please double check everything you’re doing with the latest wiring diagrams from the manufacturer. Don’t assume this tutorial is up to date.

And, here’s the new RF remote/receiver – notice the circle/tab toward the back of the board. That’s the buzzer. If yours has one of these then you have the newer board.

Unlike the older board, to change the unique encoding all you have to do is set it on the remote transmitter and then set the receiver to auto-learn mode, with a press of a button and you’re done. Well that’s the overly simplified explanation.

Here’s an overview of the receiver board with the location of the learn button marked at the bottom left.

Procedure to Learn and Erase Codes

• Press the “Learn” button on the receiver board, the siren will beep indicating the receiver is ready and waiting to learn from transmitter.
• Press any designated keys to teach and select Output modes. (See list below)
• If you need to reset/erase the the receiver due to lost or new remote, press “Learn” button for ~10sec until the siren beeps 3 times, which indicates previous learned codes have been erased.

Output Mode selection

Press 3 for Momentary Mode
Press 6 for Latched Mode
Press 9 for Toggle Mode
Press 12 for Ch1-Ch6: Toggle Mode, Ch7-Ch12: Momentary Mode

To set the encoding, first open up the transmitter

The chip at the bottom labeled SC-2262 is what does all the work.

Remove one more screw and separate the green circuit board from the casing

Notice the 3 rows of 8 little solder tabs at the bottom. That’s where you set the unique code using a soldering iron (one of 6561 or 3×8 combinations.)

Pin 1 through 8 bring out the Encode function of your remote transmitter. The receiver board will automatically learn from the transmitter by pressing the learn button.

On the older boards they used to labels the back of the board with a “H” for High, “L” for Low and numbers of the pin outs. Unfortunately the newer boards don’t have this luxury. I’ve marked up a photo to show the pin outs.

Low or ” L” – Low digital state (Close to GND level).
High or ” H” – High digital state (9-12V).

You should also be able to figure out the “L” and “H” states yourself. After you connect the system to power, use a Voltmeter to measure the contacts on both sides of the column of eight pins (1-8). Voltage level on each side should be consistence. If one side is “H”, the other side should be “L”. “H” level voltage can be measured only when signal is transmitting/receiving. Or simply use the above photo as reference.

Also, you don’t have to connect all eight pins to High or Low, just one will do. In my case pins 3 and 4 are connected to Low, and 7 to High.

Often remotes are default encoded to be 00000001, i.e. pin 8 is shorted to GND.

Encoded IC has following representation:

If the pin is not shorted to anything, its code value is “0”.
If the pin is shorted to Low, its code value is “1”,
If the pin is shorted to High, its code value is a “2”.

A couple of useful sites

• Light Object – they sell on ebay under the name of coldfusionx, are based in the USA and a lot of R2 builders buy their boards from them. This link has a bunch of support documentation on it.
• R2-R9.com – Jerry Green’s write up on integrating the remote with a CF2 sound system.
• AlexKung1.com – Alex’s original RF remote write-up.

Warning: I’ve just been informed that the Positive/Negative terminals are swapped on the new and old boards. Please double check everything you’re doing with the latest wiring diagrams from the manufacturer. Don’t assume this tutorial is up to date.

I was going to add a few more coats of paint to the skins today, but on close inspection in the daylight they looked fine. A lot of the dust spots I was seeing yesterday just rubbed off with my finger now that the paint has had time to dry. I’m going to leave it a few more days before I attempt to remove the masking tape, as it’s been pretty cold and I’m not sure how the paint cures in this sort of weather.

I’ve decided to re-assembling R2. Started off with something easy – the center ankle as it’s relatively simple and self contained. I need to get him back on 3 legs to start laying out the electronics again. I’m probably going to move things around a bit, for example I know the speed controller can’t stay where I had it on the back mounting plate as it now hits the skins. It may end up on the back side of the plate or somewhere else internally. I also want to build in some sort of switch and circuit to allow me to charge the batteries in place rather than having to remove the cables each time to clip the charger on.

I’ve been paranoid all week that I’m going to ding or mark the paint, and tonight I had to moved passed that. Right off the bat there was no avoiding dirty fingerprint from the grease when handling the new white paint, plus I scratched a some paint off trying to get the ankle to fit back in the foot shell slot. I really should have filed down the metal parts a long time ago to compensate for the added paint – but I didn’t. I’m sure it going to wear off in this spot anyway, but don’t ya hate it when something like this happens?

I’m glad now that I didn’t get things powder-coated and at least I can touch it things up myself if I need to.

I’m going to have to keep an eye on the foot shells as they’re steel and prone to rust, especially where I live on the coast. It’s ironic that one of the reasons I went with an aluminum droid was because wood warps so easily here, even when sealed, and now here I am worrying about rust from the salt air. I may just grease up this area when I get around to weathering him.

I also noticed that nearly all of my ankle cylinders are scratched up and should really be repainted, but I’m not going to do it this time around.

I used silicon to attach the foot strips to the foot shell. I should probably tap and screw them on, but I’m feeling lazy and really want to see this done. I roughed up the two surfaces and taped on the strip. I’ll probably know tomorrow if it works.

I think it looks pretty cool all put together don’t you think?

One last thing while I remember, don’t forget to use screw Loctite or something similar. I missed a few screws in the feet before C4 and lost nearly all of them by the end of the week.

For those of you following along from the start you’ll know that I’m using the Vex System to control my droid.

Vex was originally a joint venture between IFI Robotics and RadioShack, but they parted ways back in 2006 and IFI took full control of the Vex Labs company.

Recently Vex Labs introduced the second generation Vex system called Vexplorer. On the surface it’s a simpler (and cheaper) design, but does have some cool things in the starter kit like a 2.4 GHz remote camera. The remote transmitter is a lot smaller too, more like a game controller.

It maybe worth checking out if you’re shopping around for a programmable micro-controller to run your droid.

Looks like the micro-controller is NOT programmable. So I can’t see this being much use beyond using it as a standard RC setup.  VexLabs has dubbed the new controller Vex-Blue vs Vex-Red for the original system I use.

Three big milestones the last few nights. One, I finished gluing the skins together, two, I mounted the skins to the frame, and finally – I’ve almost finished painting the white parts including the skins. I can’t believe it!

Front skins were a little more tricky than the rear as I needed a lot more clips. I also had to go buy more of them as the rear skins were still drying.

Do yourself a favor and go to a 99c store and pick up 20 packs of these before you start anything. I estimate that I used around 60 clamps for skins in total. You maybe need a few bigger/stronger clamps just in case you get some spots that want to pull part, and a box or two of those black binder clips just in case.

These little clamps are probably useless for anything else you’ll work on in your life, but they’re perfect for the skins and very cheap. You could easily blow much more by going to a regular hardware store and stocking up on name brand clamps.

I’d noticed that very few builders have photos of how they glue the skins together. There’s plenty of before and after shots, but nothing during. Now I know why. It’s incredible messy and you’re in such a hurry in case the glue sets!

Once again I used the cheap 60 minute epoxy. I turns out that one pack was enough to do all of the skins and panels.

Before I applied the epoxy I cleaned the surfaces with Acetone, and double checked any tabs that I may have missed. It’s worth checking as once the skins are stuck together it’ll be really hard to get in to file them down.

Okay, here’s the obligatory after photo

I used Acetone again to clean up the excess epoxy that oozes out everywhere. I went back around again after an hour to clean up even more that came out. I pulled off each clamp one by one so I could get underneath.

It’s probably worth checking all the seems around the whole outside of the skins as I had some spots that small clamps wouldn’t hold together. In fact I missed a few places and now I have to live with it. Also, don’t forget to keep the skins in the same half circle as the frame. They will most likely de-laminate if you don’t keep them curved correctly.

Here’s a quick shot of the rear door outer skin with the epoxy on before I stuck the pieces together

By the time I’d got to the door I’d cut way back the amount of epoxy I was lathering on. It still set up fine and cleanup was a lot easier.

You’ll also notice that I cut out all of the the large panels at the last minute. I’d hoped to keep them in place but it was virtually impossible to get the skins to bond together without gaps otherwise.

While the skins were drying I tackled turning this box of bits into assembled skin panels

Clean up of the edges and tabs was pretty easy, but I had some trouble getting the door frame surrounds to stick to the inner/back panels. A few days ago I’d tried silicon, but some of them kept de-laminating.I know Victor and many others swear by silicon, and I’m sure I was doing something wrong.

I tried one door three times but the silicon would just not hold it together, three others I did at the same time worked great. Go figure. Cleaning up the silicon after it had dried was also slow going for me. And with the success and relatively easy cleanup of epoxy on the skins I opted to use it instead on the panels. It was messy but I could quickly remove the excess epoxy while it was still wet. Again I used my trusted friend “Acetone”.

Once the skins dried overnight I was able to clean up the remaining dried epoxy and get to attaching them to the frame. Test fit without any mounting blocks seemed okay, but where I’d cut out the rear door on the skin it wouldn’t sit flush to the frame, it flared out a lot. It looked like I may have to add some blocks or mount pointer on the lower half of the frame.

Fitting the skins to the frame took a little longer than I thought it would. I’m using Daniel’s mounting blocks and it look a while to figure out how I was going to measure and mark up where to drill the holes in the skins. The blocks are designed to fit the JAG frame and screw to three of the frame rings.

At first I thought I needed to attach the block to the frame first but I quickly realized that it would be hard to center, so I opted to mark a line on the inside of the skin where the ring was and attach the blocks to the skins first.

In the end I worked out the math and a little system and I only screwed up on one hole. I was amazed I didn’t get them all wrong.

Now I have one elongated hole and I’m not sure if I’m going to try and fix it or not. I’ll probably leave it and see how it looks painted up.

I then tried to drill holes in the frame rings to attach the blocks to, but the skins are so tight once the blocks are in place I only really needed to attach the lower one’s. They also pulled in the rear skins snug to the frame So I don’t think I need to add extra mounting blocks there as first though. Here’s a shot of the skins without the blocks attached to the frame and you can just about see in the bottom right of the photo where the skins don’t quite meet the frame

The next day when the epoxy was set on panels I set myself up to prep everything for painting. I went over the surfaces again to make sure there wasn’t any epoxy. I also taped off the panel surround on the skin so that the aluminum would not get painted. I really like the look of Victor’s R2.

I hope that by doing this doesn’t cause me a headache down the road.

I didn’t realize it until I was done, but it took me 4 hours last night to mask everything off.

Here’s the majority of the skins and panels layed out ready for painting.

And here they are with the first coat of self etching primer

and the gray rustoleum primer on top of that

Next up was the Rustoleum Satin White (#7791). The instructions say that you can add additional coats within 60 minutes, so I did. I must have put on at least 4 coats by the time I was done. The only catch was I could see little dust and hair particles in the paint. I was in two minds to just stop and wait the 24-48 hours for it to try and then wet sand and start again. But I decided to continue as I know that the my paint job will never be perfect and besides I’m gonna weather him eventually anyway.

I also went back and tried to add a few coats to some other parts. It was early evening and it was starting to get really cold. The paint came out really strange and it orange peeled instantly. I’m not sure if it was the cold that did it or just a bad can, but I’m glad it wasn’t on the skins. The horse shoe can easily be sanded down and re-painted later – much easier than the skins.

I tried to capture the orange peel look in this photo but it’s hard to capture. Click through for the larger version and you’ll probably see it better.

My wife is also sick of the paint smell in the house. Even though I paint outside I bring stuff in to dry to avoid dust. I tried to fix the fumes problem last night by duct taping the door between the laundry room and garage, and it worked. She didn’t complain once after.

Tomorrow I have to decide if I’m going to continue painting the skins or call it done and wait for them to dry properly.

I also have a possible event on Saturday, but I dont think the paint will have dried enough and give myself time to re-assemble everything. I know if I push it I’ll screw something up and I’ll need to start over on the paint.