Drift chassis question

[Mechbuilds]

When building a drift chassis out of lego, which is better: RWD or 4WD? 
Should you go for all locked diffs or all open diffs or front open rear locked? 

Which motor configuration is best, buggy or L motors or what?

Are the configurations scale specific? 

Small scale: 15 ish stud wide
Medium scale: 21 ish stud wide
Larger scale: 31 ish stud wide


What i want is easy to use (only forward/backward and left/right) 
Easy to drift (tape on tyres) 
Strong structure (no illegal connections or over complicated caster/camber setups)

So what's the best scale for this? 

I already ordered 2 buggy motors and was thinking about medium scale 4wd.. Is it a good idea for a setup? 

[nicjasno]

Rwd, no rear diff (in real life drift cars have welded diffs).

[1gor]

Complete agree with Ales ( @nicjasno ). About scale imho if you use 2 of L-motors than it is doable within 15 studs width, but with buggy motors I'm afraid that you will need a bit bigger width

[Gray Gear]

4WD is not good for drifting as it takes a lot more power to break 4 tires lose than 2. Just put the 2 buggy motors on the rear axle, no gears inbetween. Keep it simple!

[nicjasno]

Also, go with front caster, this way when you steer, the inner rear wheel will get unloaded and you will have an easier time breaking traction in the rear.

 

[Zerobricks]

Keep it as small and light as possible in order to break the traction. Having a very high steering angle will act as brakes enabling better drifting.

[Mechbuilds]

So basically to make a good drift car, just mass power for rear wheels and keep the chassis simple. 
What about suspension? If i'm using buggy motors, i should go with medium scale.. 
I think i want to use those charger wheels combined with those black ball joint hubs. That way i can get massive steering lock. 

Already tested this Drift chassis. Works wonders but it's very fragile.. One touch to a wall and the wheels fall off. (i don't have the narrow front wheel it needed.)
hubs using 3 studs to attach the wheels is better in my opinion and it's more sturdy. 

[Zerobricks]

I'd suggest you to use proper hubs to hold the wheels, since you will have large lateral forces. I would build in scale and use the wheels from the Charger. Suspension can be simple, as long as you use a high steering angle and caster as Nicjasno suggested.

[nicjasno]

39 minutes ago, Mechbuilds said:

What about suspension?
 

No suspension.

 

[JintaiZ]

2 hours ago, nicjasno said:

No suspension.

 

It could be added easily...

[MinusAndy]

You could go 4wd but “weld up the rear diff“, that can be lots of fun on a smooth surface. 
 

[amorti]

2 hours ago, JintaiZ said:

It could be added easily...

Once you put suspension, you need CV joints. Problem is once you're making enough power to drift a good sized model, it's usually also enough to rip the heads off the old type CV joints, but you have to use those ones with the form-piece wheel hubs.

It's probably just as well not to bother with suspension, if you can. 

Food for thought...

https://rebrickable.com/mocs/MOC-27623/Anto/ford-mustang-hoonicorn-rtr-drift-car/#info

[JintaiZ]

@amorti - Correct, but it only requires a few pieces.

[amorti]

8 minutes ago, JintaiZ said:

@amorti - Correct, but it only requires a few pieces.

Just from my own experience...

If you give it rear suspension, you kinda have to use the form piece hubs. That means using the old type CV joints.

Icarus is heavy enough that it'll snap CV joints if you give it enough power to drift. I think you have to keep it under 1k pieces for CV joints to survive for any length of time.

Or if you leave out the (rear) suspension, you can leave out the hubs, and the CV joints too.

Edited September 27, 2020 by amorti

[Mechbuilds]

Soo basically you're forced to either go small chassis that's light and low powered or a medium chassis that's high powered. 
With buggy motors, i'm pretty much going to go with no suspension, 4wd because i prefer a more easier long sustained drift. (rwd drift is pretty hectic and difficult to control.) 


Also is going for 4 wheel steering completely defeating the purpose of drifting? If i went with a "welded diff" for rear but having the rear wheels steer like 1/3rd of what the front is steering and in the opposite direction.. 
Or will that only just add more traction? 

[amorti]

Low powered? Did you click the Mustang link above? It is @16 studs with the tyres, and has a buwizz and 4*L motors in there.

[MinusAndy]

You could always buy some drift rc tyres in a compatible size to get the back to break away easier.

[Mechbuilds]

Okay guys! Here is my first prototype front axle for a drift machine:



It's 13 studs from hub to hub. +1 stud from using the "disc brakes" When you add these 4 stud wide tires, the total axle is 20 studs wide. So the car bodywork can be 20-21 studs wide.
Works with U joints. Very sturdy and no vibration at max steer thanks to U joints being awesome. 

If anyone has any ideas how to modify this axle so it's better, let me know! 
It's basically the same idea of the hoonicorn drift stang but with a differential added for better steering and it's a couple of studs wider. 


I kind of dislike how the axles are attached to the H frame. I'm trying to figure out how to make it a little bit more sturdier.. 

[rm8]

If you want to do a donuts, listen to guys who tells you about rwd. To control rwd drift car you need quick and accurate thrust and steering control, thats is kind of fairy tale in LEGO, right??

so, you need awd without center differential, with free open front diff and locked rear. Steering angle should be as large, as possible. Suspension is not needed, cause it is extra weight, and practically no pros for lego drift.

I am the rare one who tested a lot of drifting machines form lego, check this out

there is a lot theory based on lego practice in both videos below. But to understand  you need to:

1. Know russian

2. Turn on russian titles and then turn on auto-translation them to any language (in browser only)

 

 

 

Also try RC drift wheels instead lego plastic wheels or even tape covered rubber ones. Rc wheels look good, slide well even with low power, and also have good offset to use them on you front cardan-powered steering knuckles with large pivot point offset

 

My friend is crazy on drifting lego

https://vk.com/club193057769

We use buggy motors from 1 to 4 pcs. From Buwizz power to 2s/3s lipo and custom made RC adapter for RC remote controls. But drifitng with touch screen using buwizz is also possible. 

 

[Mechbuilds]

Thank you @rm8 for the input! 

Yeah my intention is not to make donuts. I want to make banana slides instead. 
So yeah, diff at front, no diff at rear and 4wd is what i'm going to go with. 

Now that i have a big steering lock front axle, my next issue is how to deal with the fact that the diff is 1,4:1 geared on the front axle. How do i match that to the rear with no diff? 
Or should i have different gear ratios on both axles? 


Basically yeah the idea of AWD drifting is that the front axle is controlling and moving the car while the rear axle tries to stay loose at all times. 
So should i try and match the same gear ratio at front or have a different ratio for the rear? Higher or lower? 

[rm8]

Use 2 pcs 1x2 thin liftarms in rear diff instead 12 bewel gears (yeah it is legal and work ok), or use new 28 tooth gear instead rear diff

[Mechbuilds]

Just now, rm8 said:

Use 2 pcs 1x2 thin liftarms in rear diff instead 12 bewel gears, or ise new 28 tooth gear instead rear diff

Ah! Of course! 

[nicjasno]

AWD will make your life just harder. As said before, rwd, no suspension, as big of a steering lock as possible and some caster in the front.

 

[ukbajadave]

Have you considered taking inspiration from the RC drift world and running an AWD "counter steer" setup? You basically gear up the rear wheels in relation to the fronts

[Mechbuilds]

1 hour ago, ukbajadave said:

Have you considered taking inspiration from the RC drift world and running an AWD "counter steer" setup? You basically gear up the rear wheels in relation to the fronts

So basically going diff front 1,4:1 and no diff rear with just bewel gears 1:1..