[TC30] Whirl and Wheel

[1980SomethingSpaceGuy]

Hi there!

For this TC, I want to ride down memory lane once again and reboot this one:


Truck and helicopter would fit the theme, I'll decide what I do about the trailer later...

I've started working on the chassis, but it's already over 150g, so I might need to reconsider.

Anyway, this is it for now; thanks for watching!

[Jurss]

Try some narrow tires, they could be lighter, also whole scale could be smaller, and as result, lighter.

[JoKo]

3 minutes ago, Jurss said:

Try some narrow tires, they could be lighter, also whole scale could be smaller, and as result, lighter.

The narrow tires this size are solid rubber, I think it won't help! The smaller scale seems the only option.

[Jurss]

But those new ones, with high profile? Need to check, havent wighted. But rubber is pretty heavy.

[1gor]

Hm...with only one driven axle is not such saving...

[1980SomethingSpaceGuy]

15 hours ago, Jurss said:

Try some narrow tires, they could be lighter, also whole scale could be smaller, and as result, lighter.

 

15 hours ago, JoKo said:

The narrow tires this size are solid rubber, I think it won't help! The smaller scale seems the only option.

 

15 hours ago, Jurss said:

But those new ones, with high profile? Need to check, havent weighted. But rubber is pretty heavy.

 

14 hours ago, 1gor said:

Hm...with only one driven axle is not such saving...

 

Thanks a lot for the feedback guys!

First, front tires were meant to be narrower. For realism to begin with. But indeed, they are not that much lighter.

I considered smaller tires and thus a smaller scale, but then the diffs won't fit. And they're the main feature.
I considered a single rear axle, but then I'd lose most of the accuracy to the original and the chassis would end up looking too much like a car's.

So I decided to push with this and instead try and save weight wherever I could. My plan now is to focus on the mechanical aspects:

• double diff
• fake V6
• steering

And to mockup the general shape of the cabin with a wireframe, old Technic style.
This should allow for decent size and mechanical complexity while still matching the weight target.

Here's what I have now; all features working fine, about 200g:

Let's see what body I can get with 100g of good ol' ABS..

[Jundis]

7 minutes ago, 1980SomethingSpaceGuy said:

Let's see what body I can get with 100g of good ol' ABS..

Uhh, this will be hard to do a cab with only 100 g left actually :-/

For this model to pull off, you really need to shed weight, e.g. get rid of the panels for the third wheel or use less connector parts on the front end.

Imho a brilliant display of minimalism is this Telehandler. "Perfection is achieved not when there's nothing more to add, but when there's nothing left to take away."

[Jurss]

Yes, also noticed those small panels, they don't seem to be necessary. Also, for estethics You will need some mudguards at rear, most probably. 

What else I can suggest, don't use half bushes at rear, turn around wheels, axles then could be shorter, and you will save some 5+ grams maybe, which You can use somewhere else.

One more thing - try to use for HOG steering half width gears.

Edited January 9 by Jurss

[1gor]

I suppose panels for cab are also to heavy...

[1980SomethingSpaceGuy]

That's the idea right now; remove everything that's not required. The front end as it was above was more of a placeholder; the way it is attached to the chassis is already gone.
Those panels for the fifth wheel are in fact quite light for their size, @Jundis, and they add considerable strength at a critical spot. The front ones will most likely be replaced when the cabin is added, but the rear ones do a nice work shaping the tail I think.

I won't be able to turn rear wheels around, @Jurss, because I need a stronger wheel attachment than only the small bevels inside the differential. This is the only way to minimize track width while still having an actual bush to retain the axle. I can remove the external half bushes themselves, which I will do if I must, but they almost weight nothing.

Indeed, @1gor, the idea is something like:

Anyway, thanks a lot for your suggestions, mates; I'll need a lot more ideas to sort the incoming challenges of a 100g cab so any is warmly welcome!

[1980SomethingSpaceGuy]

100g for cab and details definitely was not much. Here's what I could do:

It feels pretty hollow but I think there's the strict minimum design features to recognize the 5590.
I weighted the model rather often during the build and it was slightly over 300g at some point.
Surprisingly, I quite enjoyed the "what can I remove now?" game, in the end. 

[Jurss]

This is really hollow. Cab is OK, but I'm really missing seats and steering wheel.

Just don't know, what can be still optimised. OK, I would try to rework frame. Maybe something could be saved using not frames, but flip flop beams. Then You maybe wont need those small panels fro structural integrity, also for one axle all those L beams could be raplaced with T beams, which could result of saving of 8 studs of mass. A-pillars may be replaced with half beams?

[1980SomethingSpaceGuy]

I reworked the frame and A-pillars and managed to save just enough weight for seats and steering wheel.

The chassis is has bit more flex and the steering wheel of course has to be fake, but I think it was worth it.

Adding these brought me to 305g. I spent hours tweaking to save the last grams, but finally got it.

[Jurss]

Good, good! Now it is really OK.

 

[1980SomethingSpaceGuy]

Thanks @Jurss!

Checking every detail of this truck, I noticed this which I find pretty odd:

On to the chopper now...
At that scale, I won't be able to implement rotor or blade angle controls. As a feature, my idea is to use a pull-back motor and devise trigger mechanism to "launch" the thing.
That's what I've been working on yesterday.

(rotor and bevels are just placeholders)
I had my kids test it this morning; it's a bit overbuilt but it proved to be perfectly reliable so I'm fine with that.

[Jurss]

This good! If it is too heavy, You can always try rubber band in place of rubber. 

[1980SomethingSpaceGuy]

Yes, thought the same. But I'm at 65g with engine, trigger mechanism and rotor blades, so I should be fine.

[1980SomethingSpaceGuy]

I reworked the trigger mechanism to fit in the planned 7-stud wide body. I'm really happy with how well this works.

 

Edited January 14 by 1980SomethingSpaceGuy

[Jurss]

Nice!

[JoKo]

Well done!

And the tail rotor "actually" counteract the main rotor torque. Nice detail

[2GodBDGlory]

Looking good!

[1980SomethingSpaceGuy]

Thanks so much guys! 

On 1/14/2026 at 1:11 PM, JoKo said:

And the tail rotor "actually" counteract the main rotor torque.

Well that small prop doesn't have that much oomph, but the little it has must be pointed the right way! 

I've been working on the helicopter's body. 5590 has floats, but I didn't want that; I opted for retractable gear instead, with a floating body.
I managed to cram this under the friction motor and leave enough space for the cockpit.

Since this one is well under 300g, the tendency that time was towards adding too much stuff.
I did my best keeping it sober.

I like how the 24t on the friction motor's axle is so very close to the landing gear's 12t bevel...

Thanks for watching!

Edited January 16 by 1980SomethingSpaceGuy

[Jurss]

Nice to see, that there is more functionality added - that landing gear.

[Thirdwigg]

Great job so far. That helicopter looks great, and references the original set well.

[1980SomethingSpaceGuy]

Thanks a lot @Thirdwigg !

With both truck and chopper well on their way, I had to...

It's out of TC, a tad smaller than the original, very basic, almost only for the sake of the pack shot:

This set brings so many memories; my 2-year older cousin and I both got this 5590 for Christmas 1990.
The chopper's windshield was a fancy new part at that time and was put in evidence in the packaging.
As my cousin opened his box, I remember saying "what you got 2 of those?" and he replied; "yeah, one on top and another in the plastic bags, normal. Didn't you?" 

Edited January 21 by 1980SomethingSpaceGuy