Build-A-Bear

[markbt73 5316]

So this arrived yesterday while my wife and I were at the coast...

Tiny box. Probably the smallest box I've ever seen for a kit that includes a body.

Inside, none of the old Tamiya magic, just a bunch of Baggies full of parts. (except Kumamon, who gets his own little clear box.) No matter, this is going to be built to run.

Love him, hate him, or just stare at him bemusedly... here he is. He appears to be holding something that looks like a cross between Knight Rider's steering wheel and a video game controller.

Of course, if you'd rather, our old friend the cowboy is also included. Maybe they'll drive in shifts. We'll see...

Going to start the actual build tomorrow evening. I know, you guys hate waiting, but just "bear" with me...

[mongoose1983 3335]

I did not know the regular driver is also included in the box. That's great.

[backtomyroots 432]

That is one cute little bear ! Going to put him next to the driver figure in the buggy, that would be hilarious.

[markbt73 5316]

That is one cute little bear ! Going to put him next to the driver figure in the buggy, that would be hilarious.

I was actually considering putting the cowboy in the passenger seat with a clipboard, like a drivers-ed teacher...

[backtomyroots 432]

Do it, you must.

[markbt73 5316]

So, here we go... all laid out. Please note my assistant at the ready on the sofa.

Scientific fact: Cars built while watching Top Gear turn out faster.

I'll spare you the blow-by-blow; the DT-02 build process is well-documented, and not much more involved than violently shaking the box. I will say that I like the black friction shocks better than the blue Holiday Buggy ones. Looks less toy-like. (still bounces like mad, though.) This is bone-stock, except for some Anti-Wear grease to slow down the differential, and a mix-and-match set of ball bearings.

The body is red; my camera is just a little off.

Poor fellow; no seatbelt, just one screw and some servo tape on his bottom to hold him in.

That roll bar won't do him much good either.

What's wrong, Tamiya; couldn't be bothered to add a couple of ear holes?

Oh well. Anyway, it's ready for a test run tomorrow, and then I'll start doing some detailing. It's a really simple kit, but that's kind of the point, isn't it?

[Mad Ax 9313]

Good to see you're getting your 'claws' into this project. I'm glad you didn't document the whole DT02 process, that would have been so 'teddyous' it might have sent me into a 'kuma'.

[markbt73 5316]

Maiden run...

It's been a while since I drove one of these with the 380 motor. Wow, is it slow. Acceleration is OK, and it will kick up dust and slide around on dirt, but you pretty much keep it floored all the time and point it where you want to go. And whatever you do, don't try to run a battery completely flat in a 380-powered car; you'll be there all day.

And the anti-wear grease did nothing to slow the diff down. I'm not sure if I didn't use enough, or what, but after one run the diff is extremely smooth, but quite wide open. I have an idea, however. More in a bit.

Pogo sticks are staying, at least for now. I sort of like the bounciness of it. And it's very stable, even bouncing around. I only flipped it once, and that was when a tire caught the edge of a rut just wrong.

So, time to make a few changes, and I'll report back later...

[markbt73 5316]

So about that diff... I wanted to make it more limited-slip, but not lock it up entirely. I've seen several methods of doing this, but I wanted to try something else.

First, I had to get to it.

Now for the clever bit. Instead of relying on thick fluid to slow down the diff action, I wanted to make it more like a clutch-pack-type limited slip diff. I did this by adding one small piece: a used upper O-ring from an RC10 shock.

Here it is in place:

Tighten the diff cover against the O-ring, and you get a diff that's difficult to turn by hand, but not impossible. The anti-wear grease should keep the O-ring sliding nicely between the side gear and the cover, without tearing or bunching up. I tried this a while back with a thicker O-ring, and it was too stiff, but the thin shock seal feels about right.

Back out for a test drive:

Much better! You get diff action on high-grip surfaces at low speeds, but as the grip goes away, the diff tightens up, and on loose dirt it's almost like a solid axle. Turning circle isn't really impacted, but traction and stability are much improved. I'll report later on how it holds up, after it has a few miles on it.

Powerplant is still the 380, but this run was made on a 2s lipo battery, which seems to give it a bit more punch. It feels just a tiny bit quicker and faster, enough so that I'll leave it alone for now.

Oh, and I will eventually put the cowboy in as a passenger, but not yet. I have some silly things I want to try before I bother painting anything...

[markbt73 5316]

Another day, another test session...

I wanted to try some diffrent wheels and tires on it, to see what might work. The stock shoes are fine, and work well, but are sort of uninspiring.

First up was a pair of Losi Mini-Crawler wheels and tires on the back.

Looks good, color matches, and works pretty well. Softer and grippier tires cure some of the bounce in the back, and also make it a bit more neutral. Not bad.

How about drifting?

Um, no. Unless you want to do nothing but very low-speed donuts. Doesn't work at all.

Then, I wanted to try something I thought would look cool, but I wasn't at all convinced it would work well. But to my surprise, it's brilliant! It's so good, in fact, that it's staying this way, and I'm going to try to work out the few issues it does have.

Ladies and gentlemen, let me introduce... The Kumamonster!

Long front axles from a Blitzer, and Wild Willy 2 tires and wheels. It's amazing. Stable, faster than normal, goes anywhere, and the little 380 can handle it with no problem. And it looks amazing:

The only problem I was having is that the rear tires rub the body just a little bit, and that slows it down. I moved the rear shocks to the inner holes on the arms, and added a thick preload spacer to each spring, and that cured the problem.

I will probably try to raise the body a little bit as well, just to make sure they don't touch. And the sloppy steering servo saver, while fine for the buggy wheels, really lets these wobble around. I'll see if I can scare up a Kimbrough replacement.

I'm also not sold on the TBLE-02S ESC; it works fine, but I can't fathom why Tamiya would stop putting full-speed reverse in basher speed controls. How are we expected to do a proper Rockford Files-style turnaround if the car crawls along at half power in reverse?

But the big tires are staying. Now I see why you all like the Mad Bull so much; but this is better because it has independent rear suspension and a teddy bear driving it.

[Nobbi1977 1793]

That is fantastic, I now need a sand rover in my life. I have a set of those wheels in red.................

[s2-g2 432]

I'm also not sold on the TBLE-02S ESC; it works fine, but I can't fathom why Tamiya would stop putting full-speed reverse in basher speed controls. How are we expected to do a proper Rockford Files-style turnaround if the car crawls along at half power in reverse?

Ha! Now that song is stuck in my head...

Genius work, man! Love the look with the monster tires.

[Grastens 2795]

Fantastic thread! I loved the bit about the 'very low-speed donuts!' And the large tires have rekindled my ideas for a Kumamon Clodbuster...

... I do not have the budget for that now, so anybody is free to snag that project!

[markbt73 5316]

Bit of drama in the pits this week. Willy was furious that I swiped his big tires and demanded that I return them. So reluctantly, I gave them back (you don't mess with Willy). Kumamon was not happy; he gave me a very rude gesture (apparently he does have fingers after all), but was somewhat placated when I offered him these sweet vintage Duratrax tires on HPI Super Star wheels.

He seems to like them, but he keeps giving Willy the stink-eye. I hope there won't be more trouble between them.

See, this is why I don't usually put driver figures in my cars...

[Mad Ax 9313]

It seems to me that Kuma might be unbearable to live with...

[Nitomor 2122]

Looks great with the Willy's wheels. It's our anniversary shortly, Wife had a tractor for Valentines and she liked the look of this when it was first released, the big wheels makes it useable for us, might need to surprise her for our anniversary along with a set of big wheels!

[Green Meanie 59]

I wouldn't be able to resist painting him up like this.

[markbt73 5316]

So. I don't know how many of you have been watching The Grand Tour, but last week was their double holiday episode (just like with Top Gear) and they all built Meyers Manx buggies and drove them across the desert in Namibia. It was brilliant.

And naturally, I spent the whole thing thinking about Sand Rovers and how to incorporate some of their elements into Kumamon's ride.

So I dug it back out:

and first things first, that stance is all wrong. It's supposed to sit lower in the nose, and the wheelbase is way too long. And those tires are all wrong. And the front end is too wide. And with proper tires, the rear will be too wide as well.

Got some work to do. But as we're still operating under "Project Zero" rules around here, it will have to be done only using stuff I already have.

(Now... Where did that tutorial go on narrowing these things without buying any parts...?)

[Mad Ax 9313]

I thought exactly the same when I was watching GT!  I got really inspired to replicate Hammond's hopped-up off-road monster.

[markbt73 5316]

So I may have gone overboard on my solution to the body not fitting the DT02 chassis properly:

Yes, that's a re-re Kyosho Scorpion under there, with the frame rails shortened by 25mm. Easy enough to do, just drill two new holes for the rear suspension mount, chop off the end of the rail, and bolt it back together. Grasshopper wheels are made possible by HPI adapters in the front, and an old pair of Frog rear wheel hubs drilled out to fit the 6mm Kyosho axle.

It occurred to me that as much as I like driving the Scorpion, its looks never really excited me. So why not use it as the basis for something I really do like?

Next steps: build a new radio box out of styrene, actually attach the body (and move it forward ever-so-slightly), and then fill the extra holes and paint/detail it. I'm not sure, but I think Kumamon will no longer be driving...

[Grastens 2795]

I don't know if this project will infuriate Tamiya and Kyosho enthusiasts as well as haters of Kumamon, but I like it! I am eager to see how it progresses!

[markbt73 5316]

1 hour ago, Grastens said:

I don't know if this project will infuriate Tamiya and Kyosho enthusiasts as well as haters of Kumamon, but I like it! I am eager to see how it progresses!

It took me some time to work up the nerve to hack off the Scorpion chassis rails, let me tell you... but I think it's going to be worth it. Besides, that's the point of re-releases, isn't it? Guilt-free modifications and experiments?

And I have a feeling that Kumamon will stay with the DT02 chassis, but in some other as-yet-undetermined body shell. I really do like how it drives with the big WW2 wheels.

[Grastens 2795]

3 hours ago, markbt73 said:

It took me some time to work up the nerve to hack off the Scorpion chassis rails, let me tell you... but I think it's going to be worth it. Besides, that's the point of re-releases, isn't it? Guilt-free modifications and experiments?

And I have a feeling that Kumamon will stay with the DT02 chassis, but in some other as-yet-undetermined body shell. I really do like how it drives with the big WW2 wheels.

Of course! I know the feeling, having hacked up a Lancia Rally shell. Was it worth it? Not too many people seemed to like the Wheelie Rally, but then I am not sure anybody would have had the nerve to do the same thing... At least the Scorpion is a proper re-release, so experiment away!

Speaking of classics: still pushing for a Kumamon Clodbuster

[StrokerBoy 772]

8 hours ago, Grastens said:

Of course! I know the feeling, having hacked up a Lancia Rally shell. Was it worth it? Not too many people seemed to like the Wheelie Rally

But some people absolutely love it...

[markbt73 5316]

So on the other side of this project, I think I have found Kumamon a new ride to replace the Sand Rover body that I stole:

One very old, very battered Pajero Metal Top shell. Just sitting on old tires for now. It can and will sit lower, and the wheels actually line up better with the arches than they do in this photo.

This "Project Zero" idea (not buying or selling anything for a year) is making me think in new ways. I'm having more fun trying to solve problems with what I have than I have had in recent years "throwing money at the hobby."