Building a CC-02 (sorta)

[krapulax]

This is in response to a suggestion in another thread. Not the build per se (there are videos on youtube and a very good thread right here - see here http://www.rccrawler.com/forum/tamiya-xc-cc01/613617-os-builds-cc02.html) but a few details of how I built mine. Mainly pictures of what I did differently.

I didn't like the G-wagen so I decided from the get go I would not purchase the kit but rather the bits I thought are needed for what I had in mind.

An observation made in the thread linked above sparked my interest so I decided to build a Unimog on the CC02chassis, but with portals. Like a real Unimog. Hopefully Tamiya is eavesdropping.

If you're trying to save money on a kit, I would suggest this is not the way to go about it, though.

So here's the end result:

 

[krapulax]

Well, surprise surprise I can't post pictures!

 

[krapulax]

To be continued.

 

[krapulax]

Okay, let's try again.

So this is the end product:



You can already see the ground clearance and the really bad angle of the front shocks, more on that later.

This is what the portal front axle looks like:





I had to machine the portal around the C hub (so to speak) to improve steering lock. I had to take a cut about 4mm deep and 6mm long in both arms (front/rear). Axle is stock CC02. The portal fit in the kingpins with no effort, thank you Tamiya for keeping the same knuckle size for over 30 years.

This gives me a rather good steering lock with the servo at full travel (60 deg). The arm is JR, I think drilled at 30something mm radius, so it has a small leverage advantage on the wheel as well. I would guess I get about 35-40 degrees of steering lock (with some Ackerman thrown in).



And with these ballcups and balls, I have no slop. I can't remember what brand they are, I have had them a long time in my spares box. I think the cups are Du-Bro and the balls are Yokomo. I know they are 6mm dia and because the cups are some inch size very close to it but a bit smaller the combination has absolutely no slop and it's smooth and free.

The servo is a JR8915 if you can't make out the numbers, a very good servo. Old, but good. It can actually rob the ESC of power at full lock in adverse conditions, but it can shift the whole car around if the wheels are stuck. I use these servos on my CR01 with great success as well.

Heres a picture to show the plate I made to put it on top of the axle and avoid the massive bump steer otherwise unavoidable with the long suspension travel:



You can just about make out the plate and the two rear supports. There is a shorter one at the front. All three are machined Aluminium threaded all the way through and have hexes so I can tighten them down on the axle casing bolts, which have been replaced with grub screws of appropriate length. From the top, the CF plate the servo sits on is bolted to these standoffs with countersunk screws.

 

[krapulax]

Alright.

Rear end.

The G6-01 portals are designed to use with double wishbone suspension so only the fronts can fit in the CC02 axles. You need then two front axles, so you have to buy two sets of axle casings if you're doing it like me. I told you this isn't a cheap workaround. But it works this way:



The shocks are attached at the rear of the axle simply because of where I had to put the top shock brackets to satisfy the short wheelbase of the 'mog and the body post hole locations as designed by Tamiya. With the Landcruiser body on it, the shocks can be in front of the axle and attached at the ball designed in the axle case. Here's the setup I used for the 'mog:



There's a spacer there 6mm and change tall inbetween the arms with a side hole where a Tamiya 4.8mm balljoint is screwed in. A 3mm long bolt goes through the spacer and both top and bottom arms and has a Tamiya 4.8mm steel ball nut at the top. That is where the toe link is anchored. The other end of the link is anchored on the end of one the axle casing screws, just replace the original with a longer one and use another Tamiya 4.8mm steel ball nut.

Here's another view:



From the bottom, this is what the chassis looks like:



Note the four link suspension inboard brackets are all the way in and turned around for the shortest possible wheelbase.

You can also see the driveshafts are some Traxxas I had rattling around, I had to shorten the sleeves a fair bit, but there's plenty of length left. Basically I can cover the entire wheelbase range the chassis can offer. I also had to drill the end holes round because they had driving flats originally apart from the cross pin. Tamiya relies on the cross pin alone. I only have a silvercan in this thing and for that I think the pin is enough.

There are some battle scars on the bottom, just so you know where to expect contact. I see others have doubts about the four link arms using plastic balljoints, but I can assure you they will do just fine. There's actually much less slop in those than the balljoints Tamiya offers stock in their kits, so I count that an improvement.

Another detail you might notice here (it's a bit more clear in the very first picture, previous ost) is that the front top arms were replaced with the ones from the CR01 kit to get back some positive caster. If you check out the first picture you may also spot the shocks are also CR01 (yeah, I pilfered my own car for all of that, but that has been heavily upgraded with Aluminium parts from Tamiya almost out of the box so these parts were just collecting dust). The shocks have almost double the travel of the stock CC02 shocks (which are just CC01 shocks in another design) so the caster change is massive over the whole travel so far into negative territory it is defetist without this modification. By that I mean a wheel at full extension travel would push the car back instead of pulling it up as the arms compress the suspension when you're trying to climb a vertical obstacle. Counterproductive to say the least. With this modification I have a tiny negative caster angle at full extension.

One last thing about the suspension. Due to the combination of parts I used, I found I had no options from tamiya for a soft long spring, so I had to make my own. This is not as hard as it sounds, but it is a bit of a pain in the butt. I used piano wire, just a bit under 1mm, can't remember exactly the size, they are imperial and I am allergic to that. I think they are about .81mm? Look for an imperial size close to that, there aren't many. 14 active coils. Came up very nice, t full length they are exactly fro the top to the bottom of the shock. I used a thick collar (again a Tamiya part never used in any of their kits but present in all) to adjust the preload. The car sits with the shocks compressed at half stroke, exactly the way I like it.

 

[OSRC]

That looks great! Nice work!

 

[krapulax]

Okay.

The portals.

The G6-01 casings are a marvel of plastic injection molding, the idler gears are very nicely cut in brass and the main gears are cast steel. Everything goes together very nicely, but the casings are not airtight. Still need a bit of work to improve the flatness and mating. And you do have to shim the gears correctly because they can interfere with each other and you'll find a lot of brass dust in your portals after a while. Alternatively you could machine a bevel on the brass gears but that is a bit more involved. I have tried both, but since you have to shim anyway to keep the bearings and shafts from moving about, I only did one portal by machining the gears. By the way, not sure why Tamiya used two idler gears, I only used one per portal. Saves some money on bearings and some energy on drag. Plus I now have spare idlers!

Now you have to realise that the portals have three gears and six bearings (four gears and eight bearings if you build as per instructions) in a very small space. Tamiya has done their best to keep the portal casings as leak free as possible, but I guess you would still have grease coming out around the input/output shafts. What to do? I decided to use ATF for lubrication given I have bearings and gears in there, and I sealed the portals for life so to speak with Threebond because I knew the car was going to see water. That leaves the shafts. For the top shaft (input) I just decided to use a good quality rubber sealed bearing (Xray is a good start) and I accept the shaft has some clearance to the bearing bore, but that bearing is normally above the fluid level by a good margin (I filled the portals before closing with about 1ml of ATF and hope the bottom gear will fling and transport it around; the bearings have had their inner seals removed and the bearings fully enclosed have had both seals removed).

For the bottom bearing, I used another good rubber sealed bearing but the shaft is now at the bottom of the g'box and that clearance you can live with at the top is too much. So I used an inner race from a dead bearing, which I loctited (609) to the output shaft just outside the bearing and used a silicone O ring in the portal output bore to run in the ball channel. This provides some level of sealing or at least guarantees that nothing is coming in even if some ATF leaks out. The sacrificed bearings are 4mm wide so the wheel hex locks the race in place as well when you do up the wheel nut even without loctite. I can look up sizes if there is any interest. See picture below:



And another view:



You can just about make out the sacrificed bearing inner race in both shots, the O ring is a little bit tight in the portal, which in turn makes it a nice sliding fit in the bearing race channel. I guess you could superglue the O ring to the portal but I found they are a very tight fit and will not spin nor let anything leak by there. The leak if any will be between the o-ring and the bearing race or between the shaft and the bearing race. You can see there's some ATF leakage, nothing to worry about, but that is one wheel where I didn't loctite the race to the shaft. I mean I couldn't see anything before I took the wheel off, and I have over 20 batteries through since I built it.

Other details include the body posts, which I insisted on keeping in the right locations for the Unimog body, so I had to get a bit original with the rear posts:



And another angle:



You can see that I had to bring the posts together a bit because the chassis is wider at the rear (the mounting brackets are the same front and back and they serve to attach the shocks as well), hence the extra nuts on those screws, which meant I could not use the locating pins molded in the body posts. These are meant to keep the posts vertical, so I had to do replace them somehow. I cut the pins off, drilled the posts in exactly the same place with 2.5mm and put a long grubscrew through the holes. Adjustability, baby!

Now remember I mentioned the front shock angle in the first post (you can see it in the very first picture). That ugly angle happens because you have to push the brackets all the way out on the chassis rail to the last hole, otherwise you can't line up the body posts with the body holes for the Unimog. That has the undesired effect that the shocks end up at that angle. They barely function now, and can't stay like that. I can do a lot of things about that, but took the easy way out and included with my last spares order another set of the relevant parts so I will use another pair of shock brackets back to back with the existing ones to relocate the shocks. It would be easy to machine something (I have a mill and a lathe) and it is tempting, but I am generally speaking interested in what can be done with available parts because I am lazy. I also prefer as much as possible Tamiya parts. Nothing to do with some Tamiya fanatical allegiance, but most of the time the quality and finish of third party parts is not on par. If I have to have something looking crappy, I might as well make it myself, that way I have an excuse and it's cheaper! If I find something I can't make, I will consider third party if it brings a serious improvement to the car rather than bling.

Your mileage might vary.

One thing I forgot to mention about the CC02 axles is that the half shafts are not captured inside the axle in any way. The older CC01 rear axle had two extra circlips one on each half shaft behind the inner bearing so the half shafts could not come out. The CC02 doesn't have these for some reason, not sure why. Doesn't even have the ubiquitous o ring or foam disc in the drive cup to push against the half shafts coming out.

Oh, well.

I machined a groove in the longer half shafts to take a circlip (I think the correct name is E-clip) behind the inner bearing but the shorter halves have no room for a groove, the diff butts up against the inner bearing. I had to resort (again) to the ever reliable Loctite 609 on the bearings and the respective diff sun gear and crossed my fingers. So far, so good. Both axles are shimmed to take out all the play in the shafts and gears and provide good mesh between drive pinion and crownwheel. One caution, these shims are often burred so you need to sand them down a bit to deburr otherwise you will chase your tail.

 

[krapulax]

That looks great! Nice work!

I have you to thank for the idea of this whole story. When I read your thread I had no idea the G6-01 existed, let alone the fact that portals would fit the CC02 I had just learned existed a couple of days before. Like you, I often get somewhat disillusioned with Tamiya kits and take a break from following what's goin' on in their world. When I found out about the CC02 I looked at it and thought, this might be fun. I am not disappointed with it, I can tell you. The build and driving it around is good old sheer fun. The car is strong and well made in a Tamiya unnecessarily complicated but infinitely adjustable way. I like that. I like that I can mix and match whatever I have on hand or whatever I fancy without having to sift at no end through the part inventories of other manufacturers. It may actually replace my aged and well seasoned CC01 on my walks in the park with my toddler who thinks it's his pet.

Still puzzled why it is so hard to come by. Tamiya would sell a ton of these if they filled the shops and brought the price down a tad and this is only going by the questions I get around kids' playgrounds from interested parents. Kids love to bounce on it, ride it, push and shove it around and the car just takes it. The CC01 never broke anything even though it took some serious abuse and tumbles. Still with the old CR01 body (Landcruiser) in one piece albeit with some battle scars and flaky faded paint. The CC02 seems to be in the same vein so far.

 

[themountain]

Still puzzled why it is so hard to come by. Tamiya would sell a ton of these if they filled the shops and brought the price down a tad ....

l dont think that will happen...the CC02 isnt going to be a competetive kit to other crawler kits out there even when they slash 100 bucks from it...and thats coming from a diehard CC01 fan. :mrgreen:

 

[Nicadraus]

Great work! Nice to see innovative/modified set ups like yours.

 

[krapulax]

l dont think that will happen...the CC02 isnt going to be a competetive kit to other crawler kits out there even when they slash 100 bucks from it...and thats coming from a diehard CC01 fan. :mrgreen:

Dropping the price does not the crawler make. But I would challenge anyone to show me a similar product at the same price point with the same quality.

Notwithstanding, if you go over my post again you will see that I don't think the CC02 is pitched as a competitive crawler (much like your beloved CC01). Which is a good strategy because much as one would like their crawling, the market is limited. Just like the market for TRF cars. The market of the average consumer however is much wider. I am talking about people who are interested in a toy not competitive performance. How many TRF kits does Tamiya sell? And how many cheap kits? And which one of the two is the money maker? There you go.

At the price point however, you can't beat it, even if I think the price is a bit steep for what is basically a toy. The CC01 is even worse for serious crawling or anything other than bashing, really. I am not even sure what was the point of the CC01 much as I like mine. Yet they sold massively, mainly because Tamiya did what I suggested above. Low price, wide availability. Two points where they currently seem to have dropped the ball with the CC02. 50 bucks or so cheaper and it would be a lot closer to the amount of money people would not mind wasting on a toy. Provided also they find it easily.

Don't know what the situation is in the US or in Europe or elsewhere, they probably get more stock, but in Australia where I am there's only one kit on the shelf in the entire country and six weeks waiting time for an order. Spares are in the same situation. Little wonder people go for the cheapies from other manufacturers even though the quality is vastly different. It's a pity, but that's the way it is. Tamiya is in Australia just another "also ran".

 

[themountain]

Tamiyas are oddballs...always were . But for the price point they sell it here in Europe I wouldnt consider the CC02 a toy at all. I wouldnt buy that a six year old ever...he would be bored in 20 minutes .

 

[krapulax]

Yeah, I think I know what you're saying. Then again, there are six year olds who beat us at our RC track (on and off road) and know how to tune a buggy and/or a TC. Can't beat a six year old with your fifty something year old reflexes and hand to eye coordination. We also had a girl in her early teens who was the only one who could drive a TC in mod with a one-way front. For the rest of us (and there were some serious racers) it was way too twitchy (tight technical track). Each to their own.

I think the CC02 is the kind of toy one could sell either as a kit or a XB. Most people who asked me about it may not have the time I spent on mine or may be put off if they had to buy electronics, batteries, paint, tools and so on. If you add up everything you need to complete a Tamiya kit, you are pushing the kind of money you could buy a Traxxas ready to go kit. I am talking from personal experience here. A friend asked my which kit to buy for his 6 yo son after seeing my CC01. The boy would love it. But what can I tell him? Out of the box the CC01 he would get would be nowhere near mine, which is extensively modified to overcome all its shortcomings (and there's only one of those in the country as well). No, I didn't cut any of it, but it has better shocks, better springs, better steering, front suspension, locked diffs, all of that machined in house so to speak and so on. He would be rather disappointed with having to do all that work (not to say he doesn't have the option of machining parts) and buy even more stuff. My shocks are the Aluminium TRF set for I don't know what Tamiya buggy and I don't even know where the springs came from and even the springs perches are some unknown (still Tamiya) part from my junk box. Plus many other bits and bobs that make a difference and I had them lying about. A XB CC02 kit would be ideal for him.

By the way, I notice Traxxas has come a long way from the el cheapo toys I knew some ten years ago. Hopefully they'll provide some motivation for Tamiya to get off their arse and do something. Right now, Tamiya only retains the edge in the realism (and durablity) of their bodyshells, which are still the best on the market. The rest is easily done better by many other manufacturers.

Oh, and a personal wish, Tamiya should really upgrade their standard shocks and springs. They are not fit for crawlers and trying to whack in the box some surplus shocks/springs from previous kits ain't gonna work. This is one of the reasons I no longer buy Tamiya kits. I buy the body shells and the minimum amount of parts I need and make my own car like the one presented here. Not necessarily cheaper, but I can delude myself into believing that if Tamiya came out with a CC02 with portals, it would cost more than I spent on mine. Hopefully we'll never actually find out (or perhaps we should).