Original Madcap Upgrades

[Braydun 69]

Hey guys, finally got my original Madcap ripping again! Bought an aftermarket shell and decals to replace the destroyed original. Got rid of my burnt out stock diff for a custom made planetary gear diff from a decent group on ebay. Added an original aluminum motor plate because my plastic one broke, as well as some aftermarket rims and Pro-Line Blockade tires.

Upgraded all the electronics with a Fuze 60a brushless ESC, Spektrum SR315 Receiver and a cheap 4370kv brushless motor from Surpass Hobby.

Gotta say this is my favorite car to drive so far, the whine from the gearbox even with aftermarket diff sounds awesome and the way this thing handles is actually pretty decent, gotta love being able to pull wheelies while already cruising at half throttle! I'll have to figure out how to post some videos!

[Braydun 69]

Here's the original body next to the new one, this thing was beat!

[Braydun 69]

The custom made planetary gear differential I found, this thing rules so far! 

[Braydun 69]

Here's the NOS aluminum gear box plate, way better than the junk plastic one!

[Braydun 69]

All the aftermarket electronics inside except for the original Futaba S3003 steering servo. Also I'm loving the aftermarket wheels

[Braydun 69]

The $20 brushless motor from Surpass Hobby, it's waterproof but says "WAPERPROOF" on the side lmao

[Howards 457]

Excellent! That gear diff looks like the TCC diff innards with a 3d printed gear to match the astute transmission. NICE.

[Alangt4 123]

6 hours ago, Braydun said:

The custom made planetary gear differential I found, this thing rules so far! 

That looks like an egress/vanquish gear diff. Certainly the inner gears are identical as is the outer cover and screws.

[bavee 1032]

Looks great!

@Braydun, are you running this diff?

- Vintage Tamiya KING CAB HiLux Monster Racer Astute Madcap PLANETARY GEAR Diff CM | eBay

EDIT: I now see that you are using an image that is also used in my link so I think it is safe to assume you are using this diff .

[Braydun 69]

4 hours ago, Alangt4 said:

That looks like an egress/vanquish gear diff. Certainly the inner gears are identical as is the outer cover and screws.

I discussed it with the people that made it and I believe you're right, just a few custom made pieces to fit the Madcap gearbox without any modification. Also included ball bearings which is nice!

[Braydun 69]

4 hours ago, bavee said:

Looks great!

@Braydun, are you running this diff?

- Vintage Tamiya KING CAB HiLux Monster Racer Astute Madcap PLANETARY GEAR Diff CM | eBay

EDIT: I now see that you are using an image that is also used in my link so I think it is safe to assume you are using this diff .

Yes sir, that's the one! It was the cheapest replacement diff I could find without going to another already worn out original ball diff. I thought it was neat and figured there's no way I could wear this out lol

I am having a problem with my motor getting too hot and I believe that is because of gearing, correct? I am using the stock 23 tooth pinion gear with the stock I believe 70 tooth gear inside the gear box. What would be a good pinion gear size I could try?

Luckily the gearbox plate allows for adjustment for different size pinions.

[Thommo 1218]

 

17 hours ago, Alangt4 said:

That looks like an egress/vanquish gear diff. Certainly the inner gears are identical as is the outer cover and screws.

 

12 hours ago, Braydun said:

I discussed it with the people that made it and I believe you're right, just a few custom made pieces to fit the Madcap gearbox without any modification. Also included ball bearings which is nice!

 

Based on other TC info and not my own research.....  I always thought that the Avante / Vanquish gear diff was 1 tooth off in the tooth count compared with the original Astute / Madcap diff.

Has anyone made a direct comparison...... It' certainly has me interested !

Great Madcap BTW, it's a beauty !

 

EDIT :   I just did a bit of online research after posting.  I think you will find that your original Madcap diff will have 31 teeth.  The Avante / Vanquish diff has 30 teeth which for me (not to rule it out but) would bring the gear mesh with the counter gear into question.  

 

[Snappy1 966]

2 hours ago, Thommo said:

 

 

 

Based on other TC info and not my own research.....  I always thought that the Avante / Vanquish gear diff was 1 tooth off in the tooth count compared with the original Astute / Madcap diff.

Has anyone made a direct comparison...... It' certainly has me interested !

Great Madcap BTW, it's a beauty !

 

EDIT :   I just did a bit of online research after posting.  I think you will find that your original Madcap diff will have 31 teeth.  The Avante / Vanquish diff has 30 teeth which for me (not to rule it out but) would bring the gear mesh with the counter gear into question.  

 

Hey Thommo , hows things?

Your correct, the pictured diff gear is only 30 Teeth, I am sure I  have tried fitting Egress parts in the past, it wasnt happy

[Howards 457]

On 1/19/2022 at 1:52 PM, Braydun said:

I am having a problem with my motor getting too hot and I believe that is because of gearing, correct?

Those cheapy sensorless brushless motors get very hot even if you gear them right. 

[Muso31 122]

On 1/20/2022 at 2:01 AM, Thommo said:

 

 

 

Based on other TC info and not my own research.....  I always thought that the Avante / Vanquish gear diff was 1 tooth off in the tooth count compared with the original Astute / Madcap diff.

Has anyone made a direct comparison...... It' certainly has me interested !

Great Madcap BTW, it's a beauty !

 

EDIT :   I just did a bit of online research after posting.  I think you will find that your original Madcap diff will have 31 teeth.  The Avante / Vanquish diff has 30 teeth which for me (not to rule it out but) would bring the gear mesh with the counter gear into question.  

 

Hi all, has anybody ran this custom made gear diff? As mentioned here I'd have thought having one less tooth would have serious implications with the counter gear mesh? It seems the only reliable solution would be a 31 tooth diff with the geared internals? 

[bavee 1032]

Yes, I did. Used this as inspiration:

Don't know how to quote my own post but here is the result:

[bavee 1032]

To be complete. I didn't order the Ebay diff. I just ordered an Avante gear diff and made my own. Works fine until now.

I am however tempted by this:

 

[Muso31 122]

Great info cheers. Any thoughts on the custom avante geared diff handling a brushless sensored motor? 

[bavee 1032]

My only experience is with a silver can and NiMH...

[Big Jon 684]

14 hours ago, Muso31 said:

Great info cheers. Any thoughts on the custom avante geared diff handling a brushless sensored motor? 

The planetary diff internals wear quickly in a Super Astute with a mild 17.5 on grass and dirt. I’d rather have a good ball diff or TA-06 internals like Sgt Spears link above. The speed/power was just right, too, which was disappointing. Maybe a good 21.5? 
Definitely not a hot four-pole, though. These things were really meant to take really hot 27-turn or mild modified brushed motors and nicads, not the huge torque of modern brushless.

[Muso31 122]

7 hours ago, Big Jon said:

The planetary diff internals wear quickly in a Super Astute with a mild 17.5 on grass and dirt. I’d rather have a good ball diff or TA-06 internals like Sgt Spears link above. The speed/power was just right, too, which was disappointing. Maybe a good 21.5? 
Definitely not a hot four-pole, though. These things were really meant to take really hot 27-turn or mild modified brushed motors and nicads, not the huge torque of modern brushless.

I wonder if they're aluminium. I've ordered one to take a look at it. Does anybody have a TA06 steel gear diff unit to measure the dimensions? I'm wondering if the bevel gears could be housed inside a 31 tooth diff, with some redesigning of the unit.

[ruebiracer 1046]

17 hours ago, Big Jon said:

The planetary diff internals wear quickly in a Super Astute with a mild 17.5 on grass and dirt. I’d rather have a good ball diff or TA-06 internals like Sgt Spears link above. The speed/power was just right, too, which was disappointing. Maybe a good 21.5? 
Definitely not a hot four-pole, though. These things were really meant to take really hot 27-turn or mild modified brushed motors and nicads, not the huge torque of modern brushless.

The internals on my original Vanquish lasted really long back in the day. That said, we put a lot of grease in as kids, even MoS² . I think if you pack a Super Astute gear diff with a fair amount of Tamiya AW grease nowadays, it should also survive quite long 17,5t brushless, 0boost is not torque worlds apart from decent old Brushed motors like Dynatech 01/02.

Just my 5 cents. But by the way, has the Super Astute gear diff 31T? Should be a straight drop in in a Madcap or Astute? But maybe I rember wrong, my Madcap is gone 33 years already...

[Saito2 6686]

2 hours ago, ruebiracer said:

The internals on my original Vanquish lasted really long back in the day. That said, we put a lot of grease in as kids, even MoS² . I think if you pack a Super Astute gear diff with a fair amount of Tamiya AW grease nowadays, it should also survive quite long 17,5t brushless, 0boost is not torque worlds apart from decent old Brushed motors like Dynatech 01/02.

Just my 5 cents. But by the way, has the Super Astute gear diff 31T? Should be a straight drop in in a Madcap or Astute? But maybe I rember wrong, my Madcap is gone 33 years already..

My original Vanquish diff internals also lasted a long time BITD, albeit only running a "hot" Joel Johnson stock motor. Sadly, I don't think the Super Astute planetary gear diff is a drop in for the Madcap/Astute ball diff. I'm fairly certain Tamiya changed the gear pitch throughout the entire transmission for the Super Astute.

[Muso31 122]

2 hours ago, ruebiracer said:

The internals on my original Vanquish lasted really long back in the day. That said, we put a lot of grease in as kids, even MoS² . I think if you pack a Super Astute gear diff with a fair amount of Tamiya AW grease nowadays, it should also survive quite long 17,5t brushless, 0boost is not torque worlds apart from decent old Brushed motors like Dynatech 01/02.

Just my 5 cents. But by the way, has the Super Astute gear diff 31T? Should be a straight drop in in a Madcap or Astute? But maybe I rember wrong, my Madcap is gone 33 years already...

I'm pretty sure the SA diff is a lot more than 31T but the avante/Vanquish is 30T as mentioned above and appears to use the same gears as the SA. Tempted to drop a 30T geared avante diff into a Madcap running a 17.5T brushless to see how it goes as the pitch is apparently the same. I'd have thought the magic formula though would be a 31T diff redesign with TA06 internals

[Big Jon 684]

Yeah, the SA has pretty fine pitch in the transmission. I was shocked at how quickly the diff gears wore out, especially because I packed the diff with AW grease and set the slipper fairly loose.