Madcap

This is an opportunity found on internet at a very good price. The model is in relative good state with full electronic equipment and fully hopped up: I just didn't resist
A few weeks before I got it, I received a full stock of new parts for this model by pure coincidence: this allowed me to get a Madcap, even if it was in a sorry state.

The Madcap is a 2WD buggy released in 1989. It was meant to be a cheaper alternative to the Astute (kit 58080) which was meant for racing by Tamiya. Nevertheless, the Madcap revealed to be a true racer on tracks as long as it was equiped with correct options (ball bearings and hydraulic dampers to replace the friction ones included in the box). As a matter of fact, the Madcap is equiped with the Astute ball differential.

The Madcap was not a big success at the time: the Astute was preferred by racers. Cheaper at first, the Madcap needed options to be as competitive and its overall price was finally higher. The Saint Dragon which is a different bodied Madcap is so ugly that it easily explains why it never reached the top sellers lists. Although it was a good seller in Japan where the manga fashion was at its best.

So the Madcap is a model that never really found its audience because of a wrong market positionning. Excellent for racing with a serious investment in options, too much gifted and not "fun" enought for leisure, Tamiya soon stopped this market segment.

The Madcap family

It is reduced to only 2 identical models appart from the body.

58082 - Madcap

58083 - Saint Dragon

Note these two models inaugurate the blue and red friction dampers that we can still find nowadays, especially on XB models still under production. Among my models, these dampers can be found on the Madbull or the King Blackfoot for the red version, an on the Sand Viper for the blue version.

The model when it arrived

What I received was supposed to be ready to run: well, no way to run it in that state, but that's not a problem. The radio and electronic equipment is complete and functionnal, and various spare parts are included.

The model as I received it

Chassis view

A complete pinion set comes with it, as well as several spare parts not shown on the photos like two motors I will have to check. The overall state is almost good despite the dust attesting a long stay in a basement. Several parts are jammed like the dampers (probably because they need oil) and others are cracked and will need a change. Generally speaking, there's a lot of play in the assembly and I will have to disassemble the whole chassis, check it, replace parts and complete missing or bad used screws.

The body is is good state except badly drilled holes. Stickers are on but the body isn't painted: same thing for the wing except it suffered quite a lot. The rear tires seem OK and so are the spare ones. At the front, tires are just ruins and need replacement.

As usual, I will disassemble the whole chassis, clean each part, grease and replace what needs it and check it all. Afterwards, full rebuilt to make it run and then I will work on the body and wing.

The chassis

At first, I just stripped eveything down, separated plastic parts for metal parts and check every screw to throw away those that couldn't be used anymore (rust, damaged screw steps...).
Then I placed all the plastic parts into a hot water bath and I cleaned them one after another with a toothbrush and soap for washing dishes. Screws and metalic parts received the same treatment with WD40 to unjam parts and remove some rust.

Many parts then revealed worrying cracks and very basic repairs made out of glue and were systematically replaced by new ones from my spare stock. All the other were reused and will eventually be replaced if needed. Hopefully, the chassis main frame is in perfect shape except visible and normal signs of use: that was the only one I hadn't in my spare stock.

I also replaced almost every ball bearing since most of them were in a poor state. Concerning screw, I had everything in my stock to replace or complete what I needed.

Dampers requires a few hours as they were completly jammed. The hot tip is to completly disassemble them, to change the o-rings, to sand the axles with a very smooth sand paper and to polish them with a tissue you previously sprayed with WD40. Then just rebuild them and give them fresh oil. For their setup, I chose the "medium" one for the rear dampers and the softest one at the front. The first run will tell if I made the good choice.

The gearbox only needed a full cleaning and grease treatment as all the gears are in perfect shape. The way the gearbox is designed is obviously meant for racing as you only need to remove 3 screws and the gearbox cover to change the motor pinion and the spur gear and setup another gear ratio. The whole operation needs barely 5 to 10 minutes to be performed.
As a matter of fact, the gear ratio range is pretty extended: from 7.73 to 12.23 by varying the motor pinion and spur gear. I chose an 8.09 gear ratio since I decided to mount a Sport Tuned motor. My Madcap will get correct performances with almost no breakage risks (hey, it's 20 years old). About the two motors I received with this model, one just directly went to the bin. The other one is a 10x2 in perfect shape, but I think it is much too powerful for my use.

This model assembly is quite long to do, but there is no specific problem, including the electronic equipment placement as there is plety of room in the chassis. Good thing this chassis was designed to receive either a mechanical speed controller (and a second servo) or an electronic speedo (a TEU-302BK for me).

The last step is to mount a new set of tires at the front: the rubber is pretty hard so it is not an easy operation, but nothing that can be compared to the Hornet nightmare though. A the rear, I also changed to tires sicne they showed little cracks and I mounted Oval Blocks tires (the same as the Fox's). At the front and at the rear, you need to glue the tires on the rims.

So here's the result of this restoration so far:

The chassis front

The chassis rear (poor wing)

Ready to run chassis overview

While I was assembling the Madcap, different things remind me of the Sand Viper:
 The front and rear damper towers and the damper position are very similar, not to say identical
 The wing mount that can also be used to change the wing camber for an aerodynamic setup
 The disc rims and the "speed disc" sticker which are exactly the same as my Sand Viper's, colors excepted

OK, these are only minor details. But they seemed so obvious while I was in the middle of the assembly process that the Madcap really seemed to be the Sand Viper ancestor.

Setup

The Madcap is a buggy for leisure but it is gifted for racing. That's a good moment to get a quick overview of the possible setup.
 Toe in / toe out. This is the angle that each wheel makes with the longitudinal axis of the vehicle as you can see on the first above photo. Pointing like an arrow (toe in), you'll get greater straight line stability but a slughish directivity in corners. The "V" position (toe out) is the opposite. With a 2WD vehicle, it is better to toe out since most of the weight is on the rear of the chassis to get a better traction... sacrifying the front drivetrain directivity. Be careful: the above photo gives the false impression that the toe out is very consequent. In real, you can hardly notice it since the angle needs to be very low (about 2 degrees). You can set this up by adjusting the steering tie rod length.
 Camber angle. This is is the angle made by the wheels between the vertical axis of the wheel and the vertical axis of the vehicle when viewed from the front or the rear as shown on the second photo above. It is negative when the wheel top goes away from the chassis frame and positive when the wheel top comes closer to the chassis. The camber angle is only useful when negative: when cornering, the chassis rolls (to the corner exterior) and this setup places the tire naturally on the ground which gives a better grip as a greater surface of the tire is in contact with the ground. This setup is made by adjusting the rear drivetrain tie rods. On my Madcap, these tie rods are not adjustable so this is the Tamiya "factory" setup.
 The front dampers. Their setup should be very soft in order for the front drivetrain to remain as much as possible in contact with the ground. This means using the three hole piston and soft springs, even if you may have to use spacers to avoid the lowering of the front drivetrain. Furthermore, the chassis gives you three choices when fixing the damper base: close to the chassis for a better ground clearance, at the middle for a neutral setup and close to the wheel to lower the ground clearance. On the first above photo, the setup is neutral. I will modify it to the dampers close to the wheels: the ground clearance will be lower and this will bring more weight to the front drivetrain. This way, I'll get a better directivity in cornering.
 The rear dampers. After trying, the best setup is intermediate: the two hole piston. For choosing springs, it is easy: the chassis (with the stick pack) should lower a little bit when you put it on the ground (by 2-3 mm maximum). So either choose soft springs and eventually add spacers or stiffer springs without spacer. To fix them, the chassis gives you two choices at the top and three at the bottom as shown on the second photo above. After some tries, I found that the best is to use the outer superior fix at the top and the inner fix at the bottom. This provides a better ground clearance and thus, a better suspension travel.

This chassis setup is perfect for me on pothole off-road track: for in-door use on carpet, the setup will be completly different (a much stiffer suspension and a much lower ground clearance for example).

The body

Quite a lot of work for it since it was very dirty and many stickers are no longer well applied. The cockpit and the side air intakes have been badly painted with indelible ink. The wing suffered a lot and also shows a very sad repair: I still don't know how to give it back a decent aspect.

As a first step, I removed every sticker being careful not to torture the fragile lexan. As I have a compplet sticker sheet, the decoration will be totally renewed. Then, I left the body and wing take a night long bath of hot water and washing dishes liquid. The next day, I took the famous modeler toothbrush to clean the remaining dirt and strange cynalite spreads that hopefully did not melt the lexan. Unfortunately, the body has some marks that are directly into the lexan and that I could not remove.

Afterwards, I slightly recut the body as it was not well cut at some places, and then I painted it white. Theoratically, the cockpit and its rear side should be painted black. Unfortunately, the indelibile ink resisted to my cleaning. So, I solved the problem by painting the black color from the outside of the body (you should always paint lexan bodies from the inside). The cockpit sticker are not dark enough and the ink marks could be seen through them.

I just had to apply the stickers to finish the decoration and get a pretty good result given this model age and its state when I received it.

Now, the wing. I couldn't find how to repair it, so I decided to paint and decorate it straight away. I may rework it later to give it a better aspect, probably by cutting the damaged part. The only other option would be to buy a new one, but this is not in my future plans.

So here's the result after working for 2 days on the body:

Finished body

Behind the scene

On the second photo, you can see the ink marks that resisted to cleaning. This is why I couldn't use the cockpit stickers as the marks could be seen through them. With the exterior painting, the problem is solved.
On this same photo, you can see the holes drilled byt he previous owner on the cockpit rear. This massacre (Holes were probably done with a screwdriver, here I recut them) was probably meant to give air to the electronic speed controller that was fixed on the chassis plateform. Anyway, this swiss cheese was just useless: if the speedo was too hot, he should have change the gear ratio to setup a better one for his motor. I just doubt that these holes had the slightest benefit for cooling the speedo. but for ruining the body, they are juste great.

My Madcap is now finished and ready to take its first run. I only regret the sorry state of the body on which I couldn't repair much. But I may try to recut the wing to get rid of the damage part. Anyway, I didn't spend a lot to restore this Madcap, which would have been a lot different if I had to buy a new complete body.
But for now, I'm really impatient to run my new Madcap.

The first run

It took place on a pothole dry off-road track with not much grip.
The first impression is that my gear ratio choice is the good one since the Madcap gets a very nice top speed and the Sport Tuned motor gives plenty of torque at low speed. Best of all, it remains cool.
Overall, this buggy gives a good pleasure to its pilot. Its behavior is close to perfect, trajectories are precise and it is pretty well balanced. I could directly compare it with my Fox, a buggy that I especially like to drive. The Madcap is lighter: not sure the difference is huge, but the Madcap behavior gives quicker responses. This can also be caused by the motor since my Fox "only" features a standard Mabuchi 540.
The Fox front drivetrain is much smoother than the Madcap's and it is a great benefit, either for cornering on generally speaking on this difficult track. So I will modify the front dampers fixations and replace the springs by softer ones.

Appart from a rear turnbuckle break at his end of the run (a part I didn't change), the Madcap gave no bad surprise. In fact, this first run was a real pleasure and made me discover a very intersting buggy. One more to run as often as possible, which won't ease my choice in selecting models to run from my collection

  

More photos are on the gallery.

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First publication: march 02, 2009 Last modified: august 05, 2009

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