Chris.B's Sand Scorcher Build

[Chris.B 246]

For some reason,  offroad cars have never really been in my focus. I usually race onroad cars on tarmac and carpet, mainly formula and pan cars with few exceptions like my TA-04.

But then, my 6 year old son and buddy formula driver asked me, why this beetle from his Hotwheels collection has these strange front and rear protectors and cages.

I told him, that these cars were very popular beech vehicles long time ago and that they are still used in those insane desert races in Mexiko an the US. We searched the web for real life Baja Class 5 Beetles and then I realized, that there is this ancient Tamiya Sand Scorcher, originally released in 1979, which is exactly what we were talking about. Should I order it? Can such an old design be any good? Well, I ordered one...

The box it comes in is huge!

After unpacking, I was somehow overwhelmed. The packaging is incredible compared to what you usually get. And all that metal parts! In some aspects, this looks more like a scale replica of a real car than a RC model. This thing is really unique...

Looking forward to the build and will keep you updated.

 

[Chris.B 246]

Hex-Screws and ball bearings! Great!

First step is the gear box. Amazing, those cast parts. It feels like building a real car.

Here I had a small issue with the big gear on the right. It sits very tight on the brass hex, but you have to move it completely in. Otherwise the ball bearings get to much axial preload when the counterpart of the gearbox is installed and the shaft can not spin as free as it should. So keep an eye on this.

Although the manual states at the beginning, that the Sand Scorcher build does not require thread lock, it is used quite often and for good reason. So do not forget it.

[Grumpy pants 5511]

A fantastic choice 👏

[Chris.B 246]

Next steps: Universal joints, axles, torsion springs, motor and and gears and their covers. No issues there.

The motor is a perfect fit. I wonder, if other motors will also fit for a possible upgrade to a brushless system. Only a slightly bigger diameter and that won't work. I will check that in future.

Two different pinion/spur gear sets are supplied with the kit. I chose the 20/65 version which gives a final gear ration of 6.5 according to Tamiya. The other set would result in a final ratio of 9.3.

The pinion has to be moved very close to the motor to fully use the width of the spur gear. But be careful not to be to close so that the pinion does not touch the motor/gear case.

[Chris.B 246]

Now its time for the roll-over bar and the rear cage.

No surprises when assembling the two parts.

But then I had a small issue mounting the plastic part to the gear box. On the right side, the black plastic is slightly to long to match the hole for the screw with the bore in the gear box. While on the left side I could mount it without any problem, I had to cut a thin piece at the end to be able to screw it in.

I think I will change the black part to the rear guard from Xtra Speed in future. But for now, that's how it looks all together:

[skom25 2218]

I had no idea that it is made from metal! Looks super cool.

 

[Grumpy pants 5511]

Great builds SRB!s 👍

[Carmine A 2602]

Very much going to be following! I've wanted a Sand Scorcher..... forever! Already know about its classic packaging, and Tamiya was well known for its scale recreations. I built several F1 Tamiya kits back in the late 70's - early 80's, amazed by the details..... right down to accurate rack-and-pinion steering, turned by the steering wheel!!!

They have done some crazy whimsical cars (we all know that!). But Tamiya definitely makes awesome models too. The Sand Scorcher and Blazin Blazer are 2 great examples of combining RC and scale model.

...... I kick myself daily for selling my Blazin Blazer in 1990.... for $100!! 🤬🤬😫😭😭😭😭🤬

 

[Chris.B 246]

Now it's time for the dampers. To be honest, I can not believe that there is even a chance that they will not leak when filled as described in the instructions. They don't have any volume compensation.

Next is the front, no surprises there.

Now the chassis plate. Because some people had bad experiences with the durability of the FRP chassis, I will upgrade it to Carbon. That's why you see a 3D printed prototype part here.

[Grumpy pants 5511]

The best fix for ReRe dampers is using TRF O rings and green slime.

I can give you the part number later on today. 

[Chris.B 246]

7 minutes ago, Grumpy pants said:

The best fix for ReRe dampers is using TRF O rings and green slime.

I can give you the part number later on today. 

Thanks! But did you fill them almost completely as depicted in the manual?

[Grumpy pants 5511]

2 hours ago, Chris.B said:

Thanks! But did you fill them almost completely as depicted in the manual?

I bought the parts and never built the shocks to be fair, the tip would have come from another TC member or 2.

I bought some RCChannel coil over shocks and they have been pretty good. 

[Chris.B 246]

Up to here I really enjoyed the build but now, it became a bit annoying.

First of all I tried to finish the wheels and it took me literally hours to get the mid part of the rear rims into the tires. I searched the web for tricks but found nothing but other annoyed people or explanations like "if it does not work, you make something wrong". Maybe I did something wrong, but I do not really know what. The rubber is simply not soft and/or wide enough to slide over the rim as I would have expected. I ended up removing a bit of the non essential inner parts of the tires to make it work. That does not have any effect on the functionality but I can not imagine, how this should have worked without doing so.

The second thing was this junky mechanism box. Although I like the idea of a dust cover, I decided not to use it. Why? Mainly because of these reasons:

- The sleeve for the steering rod has quite a lot of resistance when steering to the left

- I don't understand why a servo has to be glued to a chassis instead of using servo posts and screws

- It is huge

One hint for all of you planning to use it: A standard shorty perfectly fits.

So what to do now? I found out that Tamiya themselves used a different approach on their Fighting Buggy. Although they used almost the same parts for the front and rear suspension (besides the rear torsion bars), they did use the same mechanism box. Instead, they decided to use a double deck chassis architecture.

That's what I also opted for. I designed a custom chassis allowing the use of the torsion bars at the rear with almost the same center of gravity as before. Without the torsion bars, it would have been possible to locate the Lipo on the lower deck for an even lower COG. But than it would have become necessary to switch to coil-over shocks.

And this is the result:

The Shorty Lipo is located on the upper deck:

The final assembled Sand Scorcher chassis then looks like this:

[Grumpy pants 5511]

Very nice. 

[Chris.B 246]

Some additional parts arrived from Xtra Speed: Front and rear guards

I also finally connected the servo to the steering rack. Perfectly aligned!

On the rear:

Now I could do a first test run with the chassis. Liked it!

But since I neither live in a dessert nor on a beach (sadly 😄) I will install the optional ball diff. The solid axle results in very few steering on solid ground. And I will change the wheels for those of the Buggy Champ.

[Carmine A 2602]

You're fortunate. And you're doing a great job on your better than stock Scorcher! I live in the Mohave Desert, and would love one of these... but it's not in the cards. 

I'm really enjoying seeing yours come to life!

[Chris.B 246]

This is an attempt to solve the problem of the leaking dampers by adding style. 

Luckily, the RC4WD Bilstein SZ Series shocks come in suitable lengths for the sand scorcher. Use the 70mm version for the front and the 60mm version for the rear.

Those are quite versatile. They come with internal springs, so you can use them as a replacement for the original springs and torsion bars or you can remove the internal springs and use them as simple dampers. What you should not do is keeping both. Then the spring-rates get too high.

That's how they look mounted to the sand scorcher. Front:

And rear:

I did not yet apply the Bilstein stickers because I wanted to play with different oils. Not sure how the stickers cope with that.

[Busdriver 6451]

I do like a modernised version of an SRB. It was of its time but with modern resources it’s possible to improve it no end. The ball diff is a good call. My chassis is under a Ford F150 body and is more suited to tarmac or light off-roading and it’s better than the solid axle version.

[Chris.B 246]

2 minutes ago, Busdriver said:

I do like a modernised version of an SRB. It was of its time but with modern resources it’s possible to improve it no end. The ball diff is a good call. My chassis is under a Ford F150 body and is more suited to tarmac or light off-roading and it’s better than the solid axle version.

Which body do you use? And did you also change the shocks?

[Busdriver 6451]

9 minutes ago, Chris.B said:

Which body do you use? And did you also change the shocks?

I’ll do some pictures and send them later.

[Chris.B 246]

The ball diff adds some more metal to the chassis. Looks rock solid.

As expected, much more steering with the ball diff.

[Busdriver 6451]

7 hours ago, Busdriver said:

I’ll do some pictures and send 

https://tcphotos.net/image/cecBt

[[/url][/url]

So the Ranger is on an AliExpress special metal chassis, direct servo steering , JK shocks , no torsion bars, the radio box has been adapted and fits a shorty lipo lengthways. Fitted with a Ball diff. The Sand Scorcher is a Mk1 running gear but the chassis is a combination of re re and 3 d printed. Again same shock set up. Wheels and tyres ?? Memory fails me, though I’m sure someone will tell us. This is not really a runner as no electrics apart from a servo. All the original parts are in a box under the bed. The mk1 body is the original body. All of the Mk1 bits were courtesy of @Grumpy pants still work in progress!!!

[Chris.B 246]

2 minutes ago, Busdriver said:

Wheels and tyres ?? Memory fails me, though I’m sure someone will tell us. This is not really a runner as no electrics apart from a servo. All the original parts are in a box under the bed. The mk1 body is the original body. All of the Mk1 bits were courtesy of @Grumpypants , still a work in progress project!!!

Thanks! Like the Pickup. Tyres seem to be the ones from the Buggy Champ. I have them too.

[JimBear 1074]

The Ranger looks great, @Busdriver! As does the the scruffy one - two quite different styles but still very Tamiya both of them.

I've always sort of wanted a Scorcher, but while I like the oldschool build, am I also put off by its oldschoolness, if you see what I mean. My (perhaps false) assumption is that when built stock and run, things would just fall off turning the corner (I mean, taped down servo?).

 

[Busdriver 6451]

4 minutes ago, Chris.B said:

Thanks! Like the Pickup. Tyres seem to be the ones from the Buggy Champ. I have them too.

Yes the wheels are by Pargu. Ranger ones are Brat/Ranger covers ( the back part of the wheel is original plastic) and the others are as you say Buggy Champ. I think they may also be Fast Attack Vehicle?