[HELP] Large scale suspension

[z3_2drive]

Hello, I have been busy this summer and haven't done much building, and the offroad project on my desk will most likely be taken apart because of some doubts of the eventual performance.

After spending some time in Silicon valley with NSLC, I noticed the many Tesla vehicles in the area, and was inspired to make another road-going vehicle. This time I want to focus on making a proper suspension setup based on either the Tesla Roadster or Model S, as well as a slightly different drivetrain in order to make room for the rear axle setup.

The reason I made this topic is to get some useful info about parts I could use in order to recreate these setups as realistically as possible while still retaining strength, as I hope to use them in an RC MOC capable of 19+ kmh. Here are the photos:

Lotus/Tesla Roadster front suspension:

Model S front suspension:

It doesn't have to look exactly the same, but rather perform the same functions. As for scale, the shock absorber I plan to use is this one:

Edited July 19, 2014 by z3_2drive

[Zerobricks]

AFAIK those shock absorbers are not really usefull, because their mechanism acts like the one in a chemical pen. Once you press them they go together and a second press pushes it back apart.

[z3_2drive]

AFAIK those shock absorbers are not really usefull, because their mechanism acts like the one in a chemical pen. Once you press them they go together and a second press pushes it back apart.

Thanks so much for this! I have one and I thought it was defective, you just saved me a lot of trouble Is there any reason why they work like this? Well now I will settle for custom large pneumatic cylinders (open them up, remove one of the rubber rings and place a spring inside).

[Spencer_R]

Personally, I'd avoid the dual lower pivot type design that's shown on the Model S. Those tend to require high steering forces as they approach lock.

[Hrafn]

What scale, and what wheel size, are you looking at using? Vehicles under about 1:10 scale (or with wheels smaller than the 62.4x20 ones) tend to be too small for advanced suspension geometries, custom kingpins, etc.

[VKTechnic]

I'd recommend looking at the

and studying the building techniques used there. Also, if you need an in-depth explanation of suspension features, EngineeringExplained does a good job of that

.

[z3_2drive]

I have a thorough understanding of various suspension geometries, and I'm already figuring out some prototypes, I'm just looking to get people's knowledge of any special parts out there to get these angles without cutting anything. I love nicjasno's videos but I've never seen anyone make a proper A-arm without using glue. About scale, I'll try to find a way to use the 8448 wheels. If not, then the wheel/tire combination of the 42000 grand prix racer. This was my last RC car-

I wasn't able to get any advanced features at the rear other than a swaybar and only used caster at the front to maximize the car's strength/simplicity, but this time I want to get the full package while still being purist (other than the custom electronics). I'll be posting any mock-ups I make in the next few days...constructive criticism is encouraged

EDIT: I'll probably end up using the large ball joint pieces because they have the most strength and many mounting options.

Edited July 20, 2014 by z3_2drive

[Hrafn]

EDIT: I'll probably end up using the large ball joint pieces because they have the most strength and many mounting options.

Do you mean the 10.2mm diameter ball joints ()? I've used those in some suspension experiments and found two things. First, the standalone ball joints are no good because they pull off the axle when subjected to any tensile load; it's better to use 50923 or 64276 . Second, the ball joint sockets (like this one ) have too much friction to be used in suspensions (except maybe for very large, very heavy vehicles); fortunately the balls also fit nicely between two liftarms spaced 8mm (1 stud) apart, and in that configuration the ball joint can move smoothly.

[z3_2drive]

I meant the connectors, not the standalone ball joints. I find they are perfect for heavy models, I just hope a single servo motor can move the entire assembly. If not, then I guess I could use two motors or multiple gears on the rack. That second bit is interesting, although it might take up a lot of space and require extra bracing.

[z3_2drive]

I tried to incorporate nicjasno's custom hubs to get the most strength, but it was either too bulky or the steering pivot would be too far from the wheel, so I went with his original idea shown in the 'LPEpower episode 3' video as a rough prototype. I reinforced the design a little and I will be using the Super Street Sensation's wheels. This setup will also be a good size to incorporate the pneumatic cylinder into, though it will still be a tight squeeze.

The top arm will be one of these most likely.

Here are a few photos:

One spacer was necessary:

I think the benefits outweigh the risks when not using the stronger hub piece on the front axle, but I will definitely use them for the rear. I recall my V1 chassis broke some 5.5 axles at high speeds. Now I need to come up with a good setup for the rear, centered around the custom hubs and the pneumatic cylinder. Feel free to offer any better ideas and tips!

Edited July 22, 2014 by z3_2drive