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ALEXKYRIAK

AlexKyriak’s Madcap ‘Rebuild’

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Hi all, this build thread is basically the story of how one man once saw a photo of an upgraded, hopped up car and fell in love with the aesthetic and just had to build one for himself. 
 

Only minor problem of conscience was that to build this I would have to take an almost ‘vintage’ car and turn it into the upgraded version of that vintage car.

Essentially, I wanted to restore it, but also upgrade it up directly. Without first enjoying the original car. Apologies if this is a sin...
 

So, for the purists amongst you, probably ignore this thread :) I will be taking an old Madcap and turning it into a restored and slightly modified Madcap. 
 

So, here is the original, obtained from a little known auction site:

Madcap resto-upgrade

 

Madcap resto-upgrade

 

Madcap resto-upgrade

 

Madcap resto-upgrade


 

As you can see, it’s a fine example of the car in question. It was pretty dirty all over, dust and gunk in most places. It had some fairly jammed moving parts, such as all four of the shocks, and all of the arm pivots were pretty gunky. 
 

This car was pre-ESCs and had two sets of Servos, one for steering and one for the speed controller:

 

Madcap Stripdown

 

Madcap Stripdown

 

This car is intended to be upgraded to a modern ESC and either brushed or brushless motor, but will be run on lipo.

 

A careful analysis of the car had identified a bunch of areas where upgrades were to be done. Damper mounts, shocks, steering links, ball bearings, etc  These pogo stick dampers are frankly awful...

Madcap Stripdown

 

The front and rear hubs were pretty gunked up and not moving freely or smoothly:

Madcap Stripdown

 

Luckily I had obtained an old Madcap manual which I found was actually a great thing to have, instead of relying on PDFs on the web. It’s nice to have a vintage paper manual alongside the vintage car  

Madcap Stripdown

 

I took a detailed ‘deconstruction’ set of photos to try to accurately record each step of the strip down, just so I had a decent record of the disassembly and a decent idea of each sub assembly and set of components. Much dirt and filth became apparent. Brief summary below as an example, just a couple, I took loads...

Madcap Stripdown

 

Madcap Stripdown

 

Madcap Stripdown

 

Madcap Stripdown

 

And it all ended up in small red boxes! Felt quite nervous doing this, my first major restore / rebuild.

Madcap Stripdown

 

Madcap Stripdown

 

Most of this lot made its way into a nice hot tub of soapy water and then a few sessions in a cheap ultrasonic cleaner.
 

I aimed to keep most of the chassis and drivetrain and main plastic pieces, but replace or upgrade much of the shocks, dampers, motor, esc, suspension geometry, and steering. 
 

In the meantime I had also a) designed some custom damper mounts and b) realised the full history of Madcap, Astute and Super Astute and the implications for this build. Parts availability being one of the prime drivers....

This complicated plans slightly (In hopefully a good way) as I then considered various upgrades from either of the Madcap’s more accomplished siblings. @kontemax has a pretty amazing comparison thread here and in other enthusiast Tamiya websites, well worth a read. This was useful research. 
 

Anyway, will post further updates of this rebuild / upgrade as I find the time :)  

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I will be following this one, I have been looking at the Madcap/Astute/Super Astute cars recently.

Also, nothing wrong with a restoration with period hop ups, I would really like to do that to a Mitsubishi Lancer Evo III. A great car from the factory but they can always be improved. Have to pay the mortgage off before I'm allowed a real toy car...

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Ok so time for the next update. Starting with the base chassis tub piece. Time to fit a bunch of the bits back together. Gave this tub as good a clean as I could. 
 

Madcap restore

 

The first challenge is to install the front shocks mount. I’d decided to design a custom carbon fibre front damper mount in 3mm carbon, a home made hop-up. This was to be fitted to the front chassis piece With the front arm pivots and locking piece, uninstalled pieces seen below  

Madcap restore

Test fit of the front chassis lower piece, showing the geometry of the front arm pivot axes:

Madcap restore

 

Madcap restore

 

This is the original plastic front damper mount with the locking piece attached and the blue pogo shocks mounted (one of the ‘deconstruction’ photos):

Madcap Stripdown

 

And this is the damper mount piece (still with body clip plastic fitted to it:)

Madcap build 2



Here is the 3mm front carbon damper mount. To create this,  I essentially measured the spacings between all the holes, and then traced the mount outline around them, to resemble a super astute mount piece with a few custom modifications for hole positions:

Madcap restore

 

Madcap restore

 

madcap_mounts

 

I used Fibre-lyte as usual for the custom carbon pieces, top service.

I had test fitted this component prior to completing the front install, trying hard to use the spacers and washers to ensure the damper plate was aligned in the correct position and orientation so as to be as flat as possible to it’s contact points with the chassis, this showing the test fit prior to the servo installation:

 

Madcap restore

 

I had to do this to ensure a tight fit of the relatively thinner carbon damper mount with the stock plastic pieces of the Madcap front assembly. This took a while with various combinations of spacers and washers to get the  correct offsets / spacings and to ensure a tight fit.
 

Once I had experimented with various washers and shim spacings, I installed the damper mount without the top piece, now safe-ish in the knowledge that the plate will be in the correct position:

Madcap restore

 

Madcap restore

 

Madcap restore

 

Next up is the installation of the front arms. Seeing the photos now I realise I could have done a better job on cleaning the plastic parts...!

Madcap restore

For mounting the arms,  I used shafts, shims and e-clips to replace the step screw normally used in the stock arm pivot (shown below minus one e-clip), removing a little play in the arm’s pivot axis on the shaft:

Madcap restore

 

Madcap restore

 

Madcap restore

 

So that completes the front arms. Next up will be the rear arms and rear gearbox and motor mount .... including the diff... which was an ‘interesting’ restoration, I can tell you... :)

 

 

 

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Very nice!!! I highly recommend you use the Rere super Astute Transmission. I love the ball differential that is in the Madcap and Astute, but spares are now hard to come by and the Super Astute gives you a slipper and alot more gearing options by being able to use standard 201x Spurs as well as Associated.

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Very nice work!  I was looking at doing the same before settling on a Top Force so I could have a kit again.

had a few of these over the years, looking forward to seeing the finished product 

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Next up was to do some work on the gearbox. I had agonised over whether I should get all the parts from a super astute to do this gearbox, and rightly or wrongly worked out that to get all the super astute bits would cost 63.2% of an actual super astute kit. So I thought perhaps I’d get that and do that one as a full beans hop yo Madcap, and keep this relatively tame with as much original kit as possible but with some upgrades. That plan didn’t work out so well. Watch out for other thread on this soon...

So opened the gearbox and the differential , and this dirty thing presented itself.   
 

Madcap


Tried to clean it up quite a bit, not sure how well I did but cleaned out as much of the old diff grease as possible and added new diff grease:

Madcap


Assembled. I suspect I’ll be revisiting this piece quite soon as I’m not sure it’s moving as smooth as I think it’s supposed to  

 

Madcap

 

I have some reservations about how well this diff is operating, feels like something is not quite right. Will wait till all the axles and wheels are on for a final test, but will happily strip it out if it’s not right. 

So gearbox unit with motor is now fitted. Currently just a Tamiya sport tuned brushed. Will perhaps give it a more fulsome power unit later. 
 

Madcap restoration hopupgrade


Next move is to fit the damper mounts to the gearbox. Here I again designed a couple of stay pieces and had them cut at Fibre-lyte. I made two to test slightly different geometries, a taller and a shorter, this being the taller in the photo below. Here is one of the rear damper stay elements as compared to the stock plastic part:

Madcap build

 

and fitted to chassis / gearbox:

Madcap

 

So this is where the project stands at this juncture, front and rear arms and damper stays fitted: 

Madcap overview

 

Time to fit some suspension rods  and steering rods.

Madcap

 

Above shows DT03 front steering knuckles and hubs from GPM racing and some custom built upper arms with turnbuckles from a TT02B turnbuckle kit 51000  

Madcap

 

I used some old school brass metal bearings as spacers, with an assortment of shims to reduce play, to fit the front knuckles and hubs:

Madcap

 

Madcap

 

To create the upper arms front and rear, I measure the eye to eye of the plastic arms of the stock kit (by measuring the parts prior to disassembly and also against the manual), and recreated these using tamiya ball cups and turnbuckles from the TT02B turnbuckle kit. On madcap the rear arms are shorter than front arms.

Madcap

 

Madcap build

 

Madcap build

 

Starting to come together:

Madcap

 

Then I went through same process for the steering arms, and the steering connector arm itself, for which I shipped out the adrenal stains cut a short section of 3mm threaded rod and connected to the ball eyelets (at this juncture I also ordered some protective eyewear - using the wife’s sunglasses for cutting  bits  of metal is not recommended... 😎 )

Madcap build

 

Madcap build

 

Here fixed to the steering subassembly: 

Madcap build
 

and then installed in chassis and  fitted with servo and all linked up to front arms and steering. I used a small turnbuckle to connect the servo to the steering elements.

Madcap rebuild servo

 

Madcap rebuild servo

 

Madcap build

 

So far so good. The steering and servo all move nice and freely when tested with a powered servo saver and also allowed me to adjust the geometry a bit given that some of these elements have been made by me measuring and cutting things, which may have led to small deviations from the stock parts. 
 

Next up should be shocks I think :)

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This is so awesome. The ball dif can handle mild brushed modifieds if it's on good condition and the diff halves aren't warped from over tightening. I love the ball differential, it's just so hard finding spares now. If you have any issues I highly recommend getting the Super Astute Set up. It's what I did for my childhood Astute I restored last year, and is now a constant runner with Brushless motivation.

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Madcap body and stance


Ok time for an update. Have been working on the wheels, suspension and geometry, and getting the body sorted. Current status is as per photo above. In terms of the approach I took to this phase of the project I decided to do this slightly differently, which I’ll describe below, but it essentially involved fitting wheels first, then loose fitting unfilled oil shocks, then measuring the desired lengths of shocks and deciding shock hole positions, to determine the resultant stance of the car. This is the reverse of how I’ve normally built kits in the past, which normally installs shocks first then fit them to car and select the mounting hole positions to affect the ride height.
 

But first, fitting the wheels. This car had always intended to be using the Egress wheel and  tyre combo, they’re simply amazing looking in my eyes  

Wheels

 

 First step in fitting these is to adapt the front axle to accept the hex socket type of the front wheel. The madcap was a slightly unique car in that rear hex block was a sort of interlocked threaded connection rather than a pin connection. The front is a standard free rotating axle and here I fitted a DT03 Hex Adaptor from GPM

Madcap

 

Madcap


These simply slot over the front axle:

Madcap body mount test

 

Madcap body mount test


I then fitted the wheels to the chassis with no shocks, so the whole car was ‘loose’ and the chassis base sat on the floor . This would then allow me to prop the car with spacers underneath the chassis tub to assess and determine a target ride height.

Madcap body drop

 

Madcap body drop

 

At this point I also needed to test fit the Madcap body as this is essentially required as part of the overall assessment, so I cut it out and loose fitted it. This is a replica body from TBG  

Madcap body mount test

 

Madcap body mount test

 

I had some DF03 aluminium dampers in the parts cupboard that I’d bought ages ago so I thought I’d give them a go on this car  

Madcap restoration hopupgrade

 

So I propped the car  up on a plastic block and a screwdriver handle, and had a go at setting a ride height position, setting a slightly higher dimension on the rear than as on the front:

Madcap body and stance

 

The once happy with a proposed height to try, I measured the distances between the holes on the arms and damper mounts bottom and top respectively and noted these down, but essentially this was aiming to be about 65-70mm from and 75mm-80mm rear. 
 

Whilst building shocks I then used black o-ring spacers to reduce the overall shock length to attain the target lengths. essentially the spacer limit the overall travel length of the shock and  the length itself. This is a technique I’ve used once or twice before, but I’ve never done it quite so ‘scientifically’ with so much pre-measurement (not that I’d call this process that scientific...! :) )

 

Madcap shocks

 

Madcap shocks

 

Each spacer is just about 2mm. So if I wanted to take out 10mm of length I’d put 5 spacers on. At this juncture the shocks have no oil in them, it’s just testing different combos of spacer, loose fitting to chassis and measuring. In the end I think I’ve put 8 spacers rear, and 5 front .

Madcap body and stance

 

Madcap body mount test

 

Madcap body mount test

 

Madcap body mount test

 

I also had to factor for the natural weight and droop of the car when resting, as this would naturally drop the car down.

So this is where it’s at. Probably needs a fair bit more adjustment but it’s been entertaining and interesting getting this far :)   
 

More to follow hopefully in next few days . 
 

(note on the photos... I dialled out the yellow ness due to shooting these photos in the evening under halogen lights, I needed to remove the yellowness these give to the photos, making the blues quite strong, but it’s quite cool looking, so I left as is....)

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Love it, always love your work. I’ve got a fairly standard madcap here that someone else mildly restored. Got a new set of hicaps to put on it too. Unless I put them on the super astute when I build that.. if and when. 
 

in any case looking forward to seeing the paint job B)

 

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Madcap gearbox change

so.... a short interlude. The diff I rebuilt felt a bit unsure, and it was bugging me. So I succumbed to the most heinous of RC crimes and spent more money than sense in obtaining Super Astute parts to rebuild the diff and some of the motor/gearbox. The Super Astute manual pictured above. This spread essentially covers the build amendment I’d be making to this car. 
 

 

Madcap gearbox change

I got hold of the diff parts and gears, and a metal motor plate. The pic above is the restored madcap car with plastic parts. Essentially I’d be replacing the cover, motor mount plate, and the diff. What could possibly go wrong...

Here with the cover removed:

Madcap gearbox change

 

... and I started pulling off the pinion, motor, gears, etc .

These are the new gears and parts from a Super Astute kit:

Madcap gearbox change

 

Madcap gearbox change

 

Plastic Madcap gearboxplate compared to SA aluminium gearbox  plate  :

 

Madcap gearbox change

 

These SA gears are just lurrrvely! Beautiful precision cut pieces. Pictured here are the SA diff parts:

Madcap gearbox change

 

I quite enjoyed how this diff is designed, using a configuration I’ve not see before.  See the manual pics and this photo, but essentially the four gears interlock vertically. 

Madcap gearbox change Madcap gearbox change

 

Then the assembled diff was mounted in the chassis motor housing :

 

Madcap gearbox change

 

Then this is when I had a total faceplam moment.... I realised the motor / gearbox housing part A4  is not the same between Madcap and Super Astute and I can’t fit the metal plate to this plastic motor/gearbox chassis. (What a total dumbo I am....More thorough research is topic of the day)

So, one begrudging trip to eBay later and now am awaiting for the A4 part to arrive.... so can’t do anything more on this car until parts arrive and complete the gearbox / motor rebuild....! This old part will have to go...!

Madcap gearbox

Once the part arrives I’ll complete the rear box and do the finishing touches for radio, electronics, and complete installation of minor  bits of the chassis such as battery guard, bumper, etc  :) 

Lesson Learned today.... when going off the RC piste, do thorough research on the parts you’ll need to compete the mod!!’  

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Wonderful project, and we'll documented. Looking forward to seeing it completed (not that they ever are, just in a state of evolution).

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Purely FYI, that diff design has been standard on Traxxas bandit/rustler/stampede since the beginning of time and then later used on the slash. I was a bit shocked when I saw them use that layout on the re re super astute. I guess they couldn’t fit their standard design parts in that size diff casing. 
 

glad to see your putting in the extra effort, can’t wait to see it done. 

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Great project. 

 

The Super Astute diff looks like the Avante diff from 1988. I had the original TCC transmission on a madcap chassis way back, it used a geared diff then, not sure if they changed the designed between the original and re re. 

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I am confused as to how these work. I get the hex to shaft adapter part, but doesn't the rotating wheel turn against the nut? I would think that would cause one side to tighten up while the other loosens - or is it not that big a problem in practice?

49535607923_8b06a0a5d8_b.jpg.aa75f0a6efad48ee8e993b127de1c027.jpg

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So next update on this little build. 

Madcap body fitting

As mentioned in the last episode, I was a little bit unsure about the ball diff from the original madcap, it just felt like it wasn’t working well, a bit rough.  Built the whole thing then realised I needed a different gearbox enclosure.. or at least I think I did. So anyway, ordered a super astute gearbox enclosure and the metal motor plate to boot  

Madcap body fitting

 

Madcap body fitting

Quite liking this kit, love the metal motor plate and together with the Interesting diff, this is a nice overall gearbox. I love the clear polycarbonate gear cover - is it supposed to be painted though?
 

Madcap body fitting

 

So I fitted this with a 13.5 Speedpassion brushless replacing the tamiya sport tuned brushed I had fitted up until now.
In completing the front end I realised I was a bit of an idiot and had to put the steering link rod to the underside of the steering pivot arms as it was clashing with the Madcap front G3 part. So here’s the repositioned link:

Madcap steering link

 

I also managed to find some time to finally paint the body so here’s the first fitting of it:

Madcap body fitting

 

I didn’t manage to paint the rear wing but actually it looks quite interesting clear.

Madcap body fitting

 

Madcap body fitting

 

Now need to carefully consider the decals. Won’t go stock but not sure what to do at this juncture. Just need to fit electronics and it’s all good to go 

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That is one of, if not the best Madcap I’ve ever seen, the stance is tough

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