Mechanically Functional!

Hey everyone. Before I continue with the drift project, I want to wish everyone a Happy Chinese New Year and wish you a very prosperous Year of the Boar! And now back to our previously scheduled stream of consciousness...

As I mentioned in a previous post, I wanted to use my existing transmitter from my Team Losi Mini-LST, because a) it's paid for, b) it's FM and not AM, and c) it has synthesized frequencies. I initially ordered a Duratrax 3-channel 27MHz receiver and crystal, but then I thought the Team Losi receiver would be a little more flexible. I'll probably hold onto the Duratrax receiver and maybe throw that into my E-Maxx if I ever upgrade its radio system to FM.

To handle steering duties, I decided to go ahead and start with an upgraded servo, since every standard servo I've used in the past was either too weak or self-destructed, albeit with a little assistance from me. I went with the Futaba S3010 because it has 90 oz-in of torque at 6.0V and a speed of .16 sec/60 degrees at 6.0V. Compared to the S3001 at 57 oz-in and .19 sec, it appears to be a much better performer. I decided not to go all the way to the S3305 with metal gears, because the only action this car is going to see is on flat surfaces. It is a drifter after all.

Finally, I'm using the included Tamiya TEU-101BK electronic speed controller (ESC) with reverse. It's probably not the best ESC out there, but it is matched with the motor, and at this point, the weakest link in the drifting chain is yours truly. This is the ESC that Tamiya includes in its Expert Built (XB) series of RTR cars based on the TT-01 chassis, so it can't be complete trash. If I find that it is limiting me at some point in the future, I'll look into replacing it when I realize why I'm doing it.


I hooked up everything and then plugged in a battery to make sure everything was working. I had to trim the tabs off of the servo and throttle plugs in order to plug them into the receiver, but other than that, everything went together just fine.

Having satisfied myself that everything was in order with the electrics, I went back to the assembly manual and started in on the steering linkage. I started putting the pieces together when I was struck by an interesting sight. The Tamiya servo saver isn't a spring-loaded unit like the Kimbrough servo saver. It was two keyed pieces that were facing each other, and the "give" is provided by a plastic clip holding them together. It's tough to describe so I included a picture of it (only one of the keyed pieces is shown). The reason why this struck me as significant is because this is the exact servo saver setup that I had to replace on my Radio Shack RC car! So to all the Radio Shack RC naysayers out there, I've got proof that some of their "toys" aren't so far removed from hobby-grade DNA.

Once I got the servo mounted and the steering linkage hooked up, it was a simple matter of using the provided servo-tape to tape down the ESC and receiver. I got the ESC taped down to the bottom of the chassis between the servo and motor, then moved on to the receiver. When I uncoiled the antenna wire, I realized that if I mounted the receiver on top of the servo where the instructions indicated, then the antenna wire would only be about four inches tall by the time I routed it through the antenna tube. If I simply stretched it straight to the antenna tube hole, I'd get about six inches of vertical length. Another option that I considered was attaching it to the rear of the battery strap, which would pretty much give me the full length of the antenna wire, but that would risk pulling the antenna wire out of the receiver at every battery change. My current thinking is that I'll temporarily mount the receiver on the servo, use the antenna tube to route it straight to the antenna tube hole, cut the tube at that point and use the rest as the mast. If it doesn't cause any problems with reception, then I'll just leave it that way. I'm thinking it won't be that great of an issue, because I left my antenna internal to the body on my E-Maxx, and it didn't seem to adversely affect its range, at least in my use. It might be an issue if I raced, but that's not in the plans.

So with that out of the way, the last thing I had to do was put the wheels on. This was kinda tricky, because the drive pins kept wanting to come out since it was a fairly loose fit. I ended up just tilting the car up on its side, used the drive hex to keep the pins in place, and then tightened down the wheel. I think I may look at some aftermarket aluminum drive hexes that can be tightened in place so it's a non-issue in the future. I did notice that Tamiya had a set of drive hexes that added probably another three to four millimeters of offset. After I get the body painted and trimmed, I may throw those on to see how they affect the look of the car.

With all the wheels on, there was just one more thing for me to do. That's right -- TEST DRIVE! I didn't do anything too crazy since there was still more work to do, but I set it down on an area in my living room where the bare floor is exposed by the area rug and gave the throttle trigger a quick blip while turning the wheel, and the car immediately started sliding sideways! I was totally amazed by how easy it was to slide this car around. I am definitely looking forward to getting everything completed so I can take it somewhere with wider-open spaces.


Now that everything checked out, I wanted to go ahead and tidy up the wires. One of the things that I did was to replace the stock bullet connectors and the Tamiya battery connector with Anderson PowerPoles. This gave me a chance to shorten the wires as well as to replace low-current connectors with high-current connectors. Most people prefer the Deans connectors, but I like the PowerPoles, because I haven't really mastered the art of soldering. These connectors are rated for 45A and often used in brushless setups, so I'm confident they'll handle anything I put through this system. The other advantage is that I've already modified my batteries to PowerPoles when I upgraded my E-Maxx's connectors in preparation of going brushless some day. Now the only thing I really need to do for the chassis is to tweak the camber and toe-in. After a brief visual inspection, it appears that the toe in is okay, but the camber on the front is definitely out of whack.

Just for yucks and giggles, I threw the body shell on top of the chassis to see how it looks, and all I could think was "Wonder Woman's car if she drifted".

Shocked!

Well, I've decided that I'm going to start uploading smaller pictures. It seems to make things a little easier to read without making the pictures impossible to see things.

After a lazy morning of sleeping in, dropping off drycleaning, and taking the dog to the store to buy her treats, I got around to assembling the shocks. It's a pretty straightforward affair, requiring nothing more than following directions. Fortunately, this is my first time down this road, so it went pretty quickly.

Here are some assembly tips that I took away from this round of Build A Shock. Make sure that the burs from the trees are all trimmed off. In this case, some of them were on the shock body, so it was important to make sure these were smooth so they wouldn't interfere with the coil springs. Unlikely as it is, it just makes for a cleaner look.

The main thing I've found is to just take your time and not rush things, especially when you get to filling the shock bodies with the oil. If you go slowly, you can pretty much get through this part with minimal clean up work afterwards. In the left image, you can see one of the two O-rings used to seal the bottom of the shock.

When filling the shock body, you have to remember that this cavity will eventually need to be filled with oil, and that air will need to be bled out. Also, these O-rings are not currently lubricated, so before pushing the piston up into the shock body, I found it was helpful to twist the piston around to allow the shock oil to start filling the cavity. Once the oil was in there, the piston moved a bit more freely through the O-rings, and eventually was able to move up and down easily. If you simply push the piston up and it sticks, you may force oil out the top by accident once it stops sticking. As you can see in the right picture, there is a disc with three holes that regulates how fast the piston will be able to move as oil is forced through the holes. Oh, one more tip - be really careful when putting the e-clips on (above and below the disc), because they can fly really well! After I got the air out (tapping on the side of the shock body helps), I filled the shock body to the point where the oil climbed up the walls just to the top. There's a green rubber concave cap that sits on top, and its curvature almost matches the surface of the oil perfectly. Slowly screwing the top of the shock will allow any excess oil to come out through a small bleed notch in the threads. You can see it at the 8 o'clock position in the picture.

Once the cap comes into contact with the cap, you simply need to tighten it all the way until the cap is seated firmly. Do not tighten using the part of the cap that will go on the ballstud, as it may break off. Use the body of the cap. I found that even after a few minutes of sitting, the shock oil continued to bleed out from the bottom of the cap. This is probably just the excess making its way out of the threads. It was very handy to keep a roll of toilet paper nearby. An inelegant solution but effective nonetheless. Once the oil is in, it's a simple matter of putting on the appropriate pre-load spacers, springs, and spring retainer.

Installing the shocks on the chassis was a snap...literally. The ballstuds screw into the shock towers, and the loops at the top and bottom of the shock snap onto them. The picture on the left is of the front, and the right is of the rear. So now it's on to the electronics and servo.

Chassis Completion

Aside from the fact that the hub carriers for the front have to rotate for steering, the front end suspension arms went together almost identically to the rear. Since the front does steer, the assembly included the steering linkage. The steering linkage is adjustable, which means that the front end toe-in can be adjusted as well as the camber. Unlike the rear, the toe-in for the front can be adjusted to tweak how much the front end slides, which will obviously affect how the car steers into and through the drift.

Not a whole lot new to report, although I'm beginning to wish that I had gone ahead and ordered the optional aluminum propellor shaft, since it appears that the car has to be completely disassembled to do so. I'll just have to put my faith in the engineers at Tamiya and believe that they adequately designed the plastic stocker to take the power that will be delivered by the included motor. I'm guessing that as long as I'm not sticking in a significantly stronger motor, I should be fine.

My current overall impression of the TT-01D kit is very positive. It's interesting to note the differences between my off-road trucks and this on-road car, like the fact that the diff case is integrated into the tub chassis and split vertically along the same axis as the wheel axles instead of along the major axis of the car. The instructions are very good and easy to follow. In fact, I'd say that you have to try and screw things up, since it gives diagrams, labels, and parts references galore all in four different languages. The only two things that I think can be improved at this time are a) include the adhesive for the little metal mystery plates on the front and rear skid plates, and b) design the tree molds such that all of the parts that you need to assemble each section are on as few different trees as possible. These are minor issues, and fortunately the instructions and parts diagrams mitigate them. And with that, I'm going to call it a day on this project, because the next step is to build the shocks, and I don't really feel like filling shock tubes with oil when I'm really tired.

Rear Chassis Completed

Okay, the jewelery metal glue seems to have worked. It appears to be a thick CA glue, so that may come in handy later.

With the rear skid plate in place, it was a simple matter of installing the rear drive assemblies -- drive cup, dogbones, and wheel axle. There's a little play in the linkage, so I may come back and stuff some foam into the drive cup so that there's constant pressure on the dogbones. This may not be an issue in the end, but it's something I'm going to keep my eye on.

With the grease in the diff, the action is very stiff but not completely locked. From what I've read, it's preferable to have the rear diff locked for drifting, but this is so stiff that I'm not very concerned about it. If I understand things correctly, the reason why you want the locked diff is the fact that you want to be able to lose traction. If the diff acts smoothly like in racing, then the wheels will be able to spin at different speeds (thus the name) which improves handling and traction, which ironically is the exact opposite of what you want in drifting. If I'm wrong, I'm sure someone at some time will correct me in the way that can only happen as afforded by the anonymity provided by the Internet. That's okay, I've got my flame retardant protective gear on! :)

At any rate, the rear of the chassis is complete at this time. All we need now are the shocks, wheels, and a little bit of tuning. Tuning won't take any time at all since the rear has set toe-in and caster. The only thing I can adjust is camber, and it should be fairly easy to get the desired 0 degree setting.

Rear Suspension and Differential

Well, the assembly of the rear suspension arms went with little difficulty. Fortunately I've been down this road before, so I made sure that the camber adjustment links in the top arms rotate the same way. This is a lot different from working on the off-road trucks, because those suspension arms are so much longer than on an on-road touring car.

After the suspension arms were completed, it was on to assembling the rear differential. Since they are identical, I went ahead built them both at the same time, so I could finish all the work with the heavy grease at once. Again, the differences between the off-road trucks and this car were interesting to note. In order to keep the gears from wearing, Tamiya provided some grease for packing the diffs.

Here's a helpful hint for you if you find yourself needing to build or rebuild differentials. My wife has these sticks that she uses for her manicures; I think they're used for the cuticles. At any rate, they are roughly 1/8" in diameter, and then ends are flattened like a flathead screwdriver. Using these sticks, I was able to apply the grease to the various surfaces of the diff cup, the spider gears/shafts, and the ring gear without getting any on my hands or work surface. The best part is that they're disposable, so clean up is a snap. I also used them to apply the lubrication grease for the plastic gear surfaces.

So with all the basic parts built, it came time to assemble the rear differential. Installation was a breeze. The only tricky part was getting the front pivot points for the suspension arms lubed and kept in place while getting the diff cover on over the rearpivot points which also had to be lubed. With the cover in place, it was a simple matter of screwing down the cover part. It should be noted here that extra care should be taken when tightening screws that are going into ABS plastic, as it doesn't take much to strip the hole. Fortunately the screw I over-torqued is in a fairly safe place that shouldn't adversely affect the rigidity of the car. If there are problems later, it's nothing a little dab of thick CA glue won't fix.

Unfortunately at this point, progress came to a screeching halt as I discovered the first stumble in the Tamiya kit. The instructions call for two small metal plates to be glued to the rear skid plate, but they did not furnish the adhesive. I thought this was rather surprising considering they included the light and heavy grease as well as the oil for the shocks. I'm not sure what these plates are for, but I'm going to use some jewelry metal glue that my wife uses in her hobby. Gotta love crossover uses for household items, right? So once I get these plates glued down, I'll be ready to finish assembling the rear.

Construction Begins

Upon opening the box, the first thing I notice is that everything seems to be organized very well. Each tree of parts is in a protective plastic bag, which I'm hoping will make sense when I get into this further.

After flipping through the assembly instructions, I think that I have a pretty good idea of how to proceed, so I go back to the first page and start looking for parts. I'm initially stonewalled by the fact that the instructions call out things like GB5 in reference to the spur gear. Now I know it's a spur gear, and I know what spur gears look like, so it's a simple task to actually find it, but I'm not sure how someone who doesn't already know what they're looking for would locate it. I flip back to the end of the assembly instructions and *presto!* there is the parts diagram. As it turns out, each bag actually has a designation. In this case, GB = gear bag, and the spur gear is part number 5 per the parts diagram. One minor complaint I have at this time is that it would be nice if there were stickers on the bags that indicated which one is GB rather than have to match up parts. No big deal, though.

And as if to answer my prayers, I open the bag that contains the gear bag with spur gear, and I find that a lot of the bags do, in fact, have labels on them. Now at this point, the number of open bags is starting to get out of hand, so in order to minimize the possibility of lost parts or mixed up contents, I'm placing opened bags into ziplocs for safe keeping.

Now that I've got the bag designations figured out, things are going quicker. One interesting thing I've discovered about the TT-01 chassis is that the motor mount has a series of mounting holes whose use is dictated by the size of the pinion that you are using. I assume that this is part of what makes this kit so great for beginners, because it removes the need to set the gear mesh. By mounting the motor in the appropriate holes, the mesh should already be set. The assembly instructions show mounting positions for spur gears of 55T, 58T and 61T (stock) as well as pinions of 19T (stock) through 25T. The table even goes so far as to provide the resultant drive ratio. Now that the drive shaft, spur gear, and motor are mounted, it's time to move on to the suspension.

The Tamiya TT-01D DriftSpec Chassis

My interest in RC drifting resulted from reading an article in RC Driver magazine, where they talked about setting up a drift course and racing during lunch with their 1/18 HPI micro RS4 drifters. I really liked the idea of having a small 7" car that I could drift almost anywhere, but there was one small problem -- everywhere in the US indicated that they were waiting on delivery with ETAs ranging from early February to late March. Things weren't looking good. I did locate them at Dinball/RC Mart, a Hong Kong hobby shop that I used when I was working in China, but after shipping it became cost prohibitive.

I Googled around on "RC drifting", and pretty much every site I hit said that one of the best chassis for new drifters was Tamiya's TT-01. It is a well designed, very stable, and upgradable chassis featuring shaft-driven four-wheel drive. Plus, it is very affordable, with RTR kits running about $180. While this is a 1/10 scale chassis, it also means that it is easier to find aftermarket parts for it, which is important, because drifting is all about style. Hopefully, I'll be able to bring enough style to the table so that people will overlook my as-yet-untested drifting skillz. So I decided to shelf the 1/18 scale for now and revisit it later should I find that drifting and I agree with each other.

Upon further studies, I found that Tamiya had the TT-01D DriftSpec kit, which featured many of the upgrades that people commonly buy for drifting included in the package. Now the downside is that it is a kit, meaning there is no radio, and you have to build it yourself. On the plus side, it's a lot less expensive and I have radios from other kits. I then went to find one online, but again, it wasn't available anywhere in the US like the 1/18 cars. I checked, but I did find it at Dinball, and even with the international shipping, it came out the same price that was showing on local providers' websites before shipping. I thought that was a good deal, so I pulled the trigger.

All I needed now was to figure out how to address the servo and radio issue. I decided that I would use the transmitter from a Team Losi Mini-LST that I bought from Dinball, because it's a 27MHz FM transmitter and it uses synthesized frequencies, so I have access to all six bands at 27MHz. I ordered a Futaba S3010 high-torque servo from TowerHobbies to handle steering duties, because it not only has higher-torque than the standard S3001, but it's faster, too. Finally, I bought another Team Losi FM synthesized receiver (LOSB0801) from HopMeUp on eBay.

I was actually quite impressed, because the TT-01D kit only took a week to arrive from the time I ordered it, and everything else arrived within a couple of days. So now comes the fun part -- putting it all together.

Intro: Of Radio Control and Shack

Welcome to a number of firsts for me. This is my first attempt at a blog as well as my initial foray into the world of radio controlled (RC) drifting. If you're not really interested in how I got to this point, you might want to wait until I make my next post. I'll be perfectly honest with you -- this is a long one.

Some people have told me that I should put up a blog, but I've resisted the temptation, rationalizing it as avoiding another pit into which I can pour time and effort which would be better used doing something else. Of course, some would argue that those alternative activities would not be much different in terms of ROI. So having said that, I found myself starting this project and thought that it might be interesting to document the whole process.

I'm a casual RC hobbyist in that I like to drive the cars, work on them, install upgrades, etc. however I don't actually race them. While it would probably be very fun to do so, it also falls into the the temporal sinkhole that we discussed previously. I've always loved RC cars since I was a kid, and it wasn't really until my wife bought me a Radio Shack RC car about four years ago for Christmas that my interest was re-kindled.

Now mind you, serious RC enthusiasts will crap on any reference to Radio Shack RC cars, calling them nothing but toys and filing them away with last week's recycling. I will agree on the former, but I disagree on the latter. Yeah, the car wasn't upgradable, but it did feature things like coil-over friction shocks at all four corners, a rear differential, and digital proportional steering. As far as toys go, it was a lot of fun. It was fast, bulletproof, and I never had any problems with it until I hit a fairly immovable object (see also tree) going...well...full speed. After a few calls to Radio Shack, I was actually able to replace the steering servo along with all the stripped gears within that resulted from the ill-fated clash between car and tree.

It was this event that made me think that if I were to continue with this interest in RC, I should probably get a hobby-grade kit, complete with easily replaced parts. After doing some research, I decided to purchase a RTR 2WD Duratrax Evader ST EP (see picture below). For those of you new to RC, here are some abbreviation definitions:

• RTR = ready to run, which means you get pretty much everything you need to get out on the road immediately
• 2WD = two wheel drive, versus all four wheels being driven
• ST = stadium truck, which is the style of vehicle
• EP = electric powered, versus nitro or gas powered (see also cleaner and quieter and wife-friendly)

I drove this truck through the yard, across the street, in and out of the ditches and had all sorts of fun with it. As I broke things, I replaced them and learned about how things were put together and what effects they were supposed to have on handling. I say "supposed to have" because honestly, small tweaks don't really have much of an effect on handling when you're tearing through 2" grass and over 3-4" high roots in a 1/10 scale vehicle. Regardless, it was fun and fast. Using my handheld GPS strapped to the chassis, I got an informal max speed of 26.4mph

After bashing the yard with this truck for about 8 months, I got bitten by the bug to go four-wheeling, and the rig of choice at the time was the Traxxas E-Maxx. The E-Maxx is a 1/10 scale monster truck powered by dual 550-sized motors and powered by dual batteries. With the addition of 4WD to the equation, I was able to handle areas of the yard that had not been possible with the Evader. Even though it's a much heavier truck and less aerodynamic than the Evader, it was capable of a respectable 24.9mph in stock form. Probably not very impressive by racing standards, but it's plenty of fun in the front yard.

After a couple of months, the mod-bug bit, and it was necessary to pimp the Maxx. The most obvious solution was to replace the stock body and wheels. I got a Humvee body made by Pro-Line and designed a scheme that would look like the flag of Texas regardless of whether you looked at it from the left or right front. I thought it was a pretty decent first effort. I won't bore you with the rest of the mods, but suffice it to say that I'm at the point where the next mod will be the fairly expensive step to brushless. I've been able to avoid the financial expenditure simply by reminding myself that I don't race this truck and that I could buy another whole car with the amount required to purchase a brushless setup.

And that's pretty much how we ended up here with my latest project: the Tamiya TT-01D Subaru Impreza WRC with the DrifteSpec chassis. Drifting was started in Japan, and basically the point of drifting is to get the car to break traction such that it slides through a turn at a greater speed than if the driver were to slow down in order to maintain that traction. They do this by making the engine very powerful, the car very light, and the tires fairly hard. The best example I can give is that it's like rally car racing, only it's in the mountains, and now it's on the streets of the city. So since I can't really see myself getting my Honda CR-V sideways on the streets without attracting the attention of the men in blue, I thought I'd do it at 1/10 scale.

Now the interesting thing to note is that the seed was planted way back when I was in 8th grade. My parents bought me a Mattel RC Corvette. I remember it perfectly. It was maroon with blacked out windows, had a manually switched 2-speed gearbox, no suspension, but it did feature digital proportional steering controlled by a two-stick transmitter. Now the significance of the digital proportional steering is that with it, the wheels and throttle are affected throughout the throw of the control lever. For example, if you push the throttle stick 50% forward, the car will accelerate to 50% of its top speed. Most toy-grade RC cars these days have binary steering and throttle. They're either on 100% or off.

So why do I bring up this car? I bring it up, because I remember taking Scotch tape and wrapping the rear wheels so that I could make the car skid around corners like on the cop shows on TV. You are no doubt thinking to yourself, "Self, so what?" Well, this method of taping the tires was how drifting was initially accomplished in the RC world only a few years ago. Now, there are special hard-compound tires, but many people simply use ABS plastic pipe.

Well, I think that's enough for the history lesson. My next post will cover how I decided on this chassis.