[MOC] Trophy truck

[measyn]

Ah, another lego trophy truck...

But in this case I tried to make the suspension as efficient as possible.

Suspension

Firstly, the motors are mounted not on the rear arms, but inside the body, to make the rear axle as light and responsive as possible. The rear suspension is a four-link axle.
Front with double wishbone. Classic.
Both front and rear have 2 springs for different stiffnesses. One spring is weak and always works. The second one works when the suspension is lowered 1/3. Pneumatic cylinders are also connected to the second spring to dampen suspension vibrations. At the end there are rubber bumpers. There are sway bars on both axles.

The suspension is well tuned to the specific weight of the model and is approximately in the middle of its operating range when at rest.

All this makes the suspension very responsive on small obstacles such as rocks, grass, sand. And at the same time, the car does not spring and sway when falling and in large holes, constantly keeping all wheels in contact with the surface.

The model is very fun to drive on difficult surfaces, handles pleasantly and predictably.

Specs

The weight of the model is 1150 grams, weight distribution: on the front axle 550, on the rear 600.

The model drives with two buggy motors, steering using a geekservo. Powered by a 3s lipo battery and custom electrics with radio control.

Additionally, the rear axle uses a custom frame printed on a 3D printer with bearings to reduce wear on parts. The hubs are also 3D printed with bearings. Actually, when using a 2s battery and lowering the main gear, regular plastic parts work just fine. For some time.

The body of the model is made conventionally, some basic Ford-like truck.

The model can be modified by you to use buwizz, you just need to lengthen the chassis for the steering motor. You will get a longer car, such as a Silverado Prerunner, Toyota Tundra or F150.

 

Download instruction

Studio file

bricksafe

 

Edited January 18 by measyn
added studio file

[Daniel-99]

Hey, man! It was a pleasure to see not just "another trophy truck", but a mechanical masterpiece in action. The suspension is working amazingly! More importantly you was able to design such suspension by only using Lego parts, congrats! I was not that clever and patient in the suspension development and switched to RC shocks in my trophy truck Eagle V2. Our truck has many many ideas in common, so I would call yours a "little brother" of mine, if you do not mind! 

Edited January 18 by Daniel-99

[Igor1]

Great model! The suspension works amazingly! Can you please tell us in more detail how the performance of the suspension with sway/anti-roll bars changes directly in your model? Have you tried testing/comparing the suspension without them?

[Krxlion]

Indeed great design, in your slowed fragments of video we can clearly see you did a good job with that suspension! The exterior looks pleasant and overall perfomance of the car is great! I was for sure thinking that it is powered by some sort of brushless motor, but I am more and more surprised by performance of buggy motors plugged to RC system. The usage of technic pistons is very catchy and it does great job. I am waiting for more MOCs from your side, thanks for sharing :)

[Zerobricks]

Well done! Can you show the front, portal hubs in more detail? Any issues with the wheel falling off?

[measyn]

5 hours ago, Daniel-99 said:

Hey, man! It was a pleasure to see not just "another trophy truck", but a mechanical masterpiece in action. The suspension is working amazingly! More importantly you was able to design such suspension by only using Lego parts, congrats! I was not that clever and patient in the suspension development and switched to RC shocks in my trophy truck Eagle V2. Our truck has many many ideas in common, so I would call yours a "little brother" of mine, if you do not mind! 

Thanks! I saw your creations, great power/weight ratio design. It was a big temptation to copy the chassis.

Yes it was a long journey, maybe a year of experiments. I wanted to pack as complex suspension as i could with 75-78mm wheels. But one day it finally drove at full speed over bumps, like a lizard running through water. Also didn't want to use any rubbers, they tend to loose with time.

2 hours ago, Igor1 said:

Great model! The suspension works amazingly! Can you please tell us in more detail how the performance of the suspension with sway/anti-roll bars changes directly in your model? Have you tried testing/comparing the suspension without them?

Thans! Yes, i did a ton of experiments, detaching sway bars, pneumocylinders. With sway bars car tends to do a fancy slide while cornering, and without them to roll over. Two moments in a video when car flips over, and almost did it again was in moment when i loose one of the links to sway bar in front.

[2GodBDGlory]

Indeed, that looks very nice! I like seeing the use of those Ducati shocks here.

One question: Do you think you need to have those hoses connecting the top and bottom of the pneumatic cylinders? It doesn't seem to me like that would do much at all, other than maybe adding a little resistance based on the different surface areas of the two sides of the cylinder.

Thanks for sharing a Stud.io file! I may try building it sometime

[Igor1]

Regarding the connection of pneumatic cylinders, have you tried connecting them crosswise so as to further enhance the work of the anti-roll bar of the suspension? If you connect the top of the right cylinder with the bottom of the left and vice versa.

[2GodBDGlory]

14 minutes ago, Igor1 said:

Regarding the connection of pneumatic cylinders, have you tried connecting them crosswise so as to further enhance the work of the anti-roll bar of the suspension? If you connect the top of the right cylinder with the bottom of the left and vice versa.

Hmm, that would be neat! I doubt it would work long-term, though, because you'd get too much leaking in the closed system

[Krxlion]

About that part, I was thinking would they not wear out(pneumatic cylinders), because of dirt coming straight to those pistons. I recon those elements are not that cheap, so I wouldn't go so wild with those. 

[measyn]

3 hours ago, Krxlion said:

Indeed great design, in your slowed fragments of video we can clearly see you did a good job with that suspension! The exterior looks pleasant and overall perfomance of the car is great! I was for sure thinking that it is powered by some sort of brushless motor, but I am more and more surprised by performance of buggy motors plugged to RC system. The usage of technic pistons is very catchy and it does great job. I am waiting for more MOCs from your side, thanks for sharing :)

Thanks! Will see, my next goal is I-beam front suspension 

[measyn]

3 hours ago, Zerobricks said:

Well done! Can you show the front, portal hubs in more detail? Any issues with the wheel falling off?

Its some kind of 32184 replacement. I personally use just with one-side bearing, it's enough for me. And also 5*7 frame

 

Actually wheels fits very well, because i use some reinforcement with 4185 pulley. The only problem is RC tires, that constantly slips off.

 

 

1 hour ago, 2GodBDGlory said:

Do you think you need to have those hoses connecting the top and bottom of the pneumatic cylinders?

That's right answer:

25 minutes ago, Krxlion said:

because of dirt coming straight to those pistons

I tried to connect upper sides of them, but it adds unnecessary stiffness to suspension, maybe should use it in some cases instead of additional springs, but pressure is leaking fast.

1 hour ago, Igor1 said:

If you connect the top of the right cylinder with the bottom of the left and vice versa.

There will be a big lag of connection, it really should respond very fast to perform good cornering. Also bars just looks very realistic and cool 

[2GodBDGlory]

1 hour ago, Krxlion said:

About that part, I was thinking would they not wear out(pneumatic cylinders), because of dirt coming straight to those pistons. I recon those elements are not that cheap, so I wouldn't go so wild with those. 

Eh, I think he's using MouldKing ones, given the metal shafts on them, which only cost a couple bucks.

1 hour ago, measyn said:

Thanks! Will see, my next goal is I-beam front suspension 

Ooh, that's always cool to see!

49 minutes ago, measyn said:

Its some kind of 32184 replacement. I personally use just with one-side bearing, it's enough for me. And also 5*7 frame

Could you share where you bought those bearings from? I might want to try acquiring some sometime.

[everybrickasculpture]

Very impressive suspension setup, well done.  I second the request for the bearings source, and would you be willing to upload the 3d printed parts somewhere?  I think those could be useful for a lot of people.

 

You will probably want to glue the tires onto the rims, and consider inserting some foam in the tires.  This is necessary for any RC with weight and power.

Edited January 18 by everybrickasculpture

[Lixander]

Hey, don`t go harsh on yourself. You did a great job overall, and the suspension is just spot on. Also the thing with the weight ratio is something that you don`t see too often, even in hobby-grade RC`s.

By the way: how did you measured the weight ratios?

[Aurorasaurus]

This is most certainly not "another trophy truck". I'm tempted to say it has the best suspension setup of any Lego trophy truck I've ever seen. Great performance and looks. Maybe you could add custom stickers to give it a slightly more trophy truck look?

[measyn]

3 hours ago, 2GodBDGlory said:

MouldKing ones

Yep, they're cheap and works surprisingly well, you can buy a ton of them. Didn't notice any difference with original.

 

15 hours ago, 2GodBDGlory said:

Could you share where you bought those bearings from?

 

13 hours ago, everybrickasculpture said:

I second the request for the bearings source

There are couple of vendors in Russia, but i printed this by myself.

Maybe this models will help you, i'm doubting about size tolerance in cross-shaped holes (because of imperfection of printing). Circular holes are fine, i'm just processing them additionally with 4.8mm drill to remove little artifacts of printing. Bearings from hardware store, they are for router bits. But you can pick any, diameters are 9.5 and 4.8mm, heigh is 4mm.

Frame and hubs model

11 hours ago, Lixander said:

how did you measured the weight ratios

Just putting axles on the scales separately, while other just standing on the table. Sum of it gives exactly overall weight, so its right. Also 45-55% or 40-60% ratio is a sweet spot in real cars.

[measyn]

9 hours ago, Aurorasaurus said:

Maybe you could add custom stickers to give it a slightly more trophy truck look?

This is a great opportunity for personalization, light bars, fire extinguisher, intercoolers in the back.

I was constantly watching YT channel WingsWorld and fall in love with the stock look of real 90's white trucks, upgraded in the garage.

 

[Lixander]

33 minutes ago, measyn said:

Just putting axles on the scales separately, while other just standing on the table. Sum of it gives exactly overall weight, so its right. Also 45-55% or 40-60% ratio is a sweet spot in real cars.

Thanks!

Also, nice source of inspiration ;))

[measyn]

By the way i found the name of technique that i used in suspension, it's called Slapper Arm

They are used for bump stops, but in my case its just stiffer springs

[gyenesvi]

That's a great build and really cool video. The suspension works really well, never seen such a well tuned one in lego.

What tires are you using? Are those 75mm? It's got a nice pattern. Do you have a link for them?

[measyn]

12 hours ago, gyenesvi said:

What tires are you using? Are those 75mm? It's got a nice pattern. Do you have a link for them?

Hello! This ones https://aliexpress.ru/item/1005002950390290.html

B type seems to be more grippy for me

Edited January 24 by measyn

[rinatfruggi]

On 1/18/2024 at 5:07 PM, measyn said:

Thanks! Will see, my next goal is I-beam front suspension 

will be intersting to see your design ideas on I-beams) im working on them almost one year
and after your MOC i will try to figure out using the pneumatic cylinder too) So you and i will have some kind of  competiton 

[gyenesvi]

4 hours ago, measyn said:

Hello! This ones https://aliexpress.ru/item/1005002950390290.html

B type seems to be more grippy for me

Thanks, I actually have type B :) But I did not remember that the other pattern in your video is type A from the same series..

[measyn]

7 hours ago, rinatfruggi said:

im working on them almost one year

Will grab some ideas)