42124 Off-Road Buggy

[kbalage]

Another test with the buggy, this time a motor swap. I was really curious to see what would be the difference in performance with an XL motor.

Well the results were quite surprising, and not necessarily in a positive way:

 

[Kostq]

So the only XL about that motor is the housing? :D

[AVCampos]

The L and XL motors have different IDs, allowing the hub they're connected to distinguish between them and regulate voltage/current as required, right?

This is a shot in the dark, but what if the performance is limited by the hub, and we'll get on the future a "pro" hub capable of handling the XL's full power?

[kbalage]

4 minutes ago, AVCampos said:

This is a shot in the dark, but what if the performance is limited by the hub, and we'll get on the future a "pro" hub capable of handling the XL's full power?

What would be the point? I need to run a few more tests and I need extra hardware for them but I highly doubt that there are any "hidden" features.

[keymaker]

8 minutes ago, AVCampos said:

This is a shot in the dark, but what if the performance is limited by the hub, and we'll get on the future a "pro" hub capable of handling the XL's full power?

Maybe Buwizz 3.0 will help to check that a bit earlier ;)

[Bartybum]

The XL and L have basically the same power requirement so I’m not surprised. It’s the same motor, but one has a larger reduction gearbox

[Zerobricks]

17 hours ago, keymaker said:

Maybe Buwizz 3.0 will help to check that a bit earlier ;)

Well, my BW 3.0 prototype sure made this set go A LOT faster and further than C+ hub. But remember all Lego models have an internal Polyfuse, so there are limits on what kind of power you can push on them.

Regarding the set itself.... Why did they put hard shock absorbers with friction pins in front when the soft ones with frictionless pins are much more bouncier (though with a lower gorund clearance).

Edited January 15, 2021 by Zerobricks

[keymaker]

40 minutes ago, Zerobricks said:

Well, my BW 3.0 prototype sure made this set go A LOT faster and further than C+ hub. But remember all Lego models have an internal Polyfuse, so there are limits on what kind of power you can push on them.

Sure thing. I was talking regarding to sentence: "we'll get on the future a "pro" hub capable of handling the XL's full power". I believe Buwizz 3.0 will allow to test the limits of C+ L and XL motors.

[Bartybum]

8 hours ago, Zerobricks said:

Regarding the set itself.... Why did they put hard shock absorbers with friction pins in front when the soft ones with frictionless pins are much more bouncier (though with a lower gorund clearance).

Yeah I dunno, it seems a really weird choice

[Reklats10]

Quote

Well, my BW 3.0 prototype sure made this set go A LOT faster and further than C+ hub.

Do you have the weight of that BW 3.0 ? I'm interested to buy one when they will be available since its possible to both have weight reduction and increased power ;)

Quote

Regarding the set itself.... Why did they put hard shock absorbers with friction pins in front when the soft ones with frictionless pins are much more bouncier (though with a lower gorund clearance).

I've modded mine to address that... almost.

On the front you can go with dark grey shocks with friction pins, a bit stiffer than light grey ones (around 20%) but a lot less than yellow stock ones and basically ideal for this model weight and the friction pins add just a little amount of damping, I've also added a 5L liftarm between the upper attach points. On the rear a single yellow one with a low attach point is a lot better too, but its still not optimal since the pivot point of the whole rear assembly is still not far enough from the wheels, so without heavy modifications of the rear its basically the best solution i've found to stay close to the original design. Ground clearance is basically the same but the suspension can actually do something compared to the original

With the suspension mods i've also shaved some weight by removing most of the panels and the front bumper (around 8-10% lighter than stock), the final look is no more an old RC car but more of an actual buggy because of the "space frame" look, I like it too.

Lose front axle is mostly fixed too, i've replaced the frictionless pin on the 5L liftarm by a friction one to limit the mecanical play, lot less tendancy to veer left or right on reverse for what I can tell.

It comes at 665g in this configuration and already can do little burnouts at startup when you floor it, so with a BW3.0 lighter and more powerful it would be quite fun I guess.

 

[Reklats10]

Back to this 41214, I've noticed that my latest rear axle suspension mod was in fact basically useless because of a major design flaw on the model...

Originally the rear axle comes with a quite short single pivot point, when you mod it with a softer setting it seems better when you press on the model, but while driving its still very hard and without any terrain sensitivity.

Its because of the stock design, when the wheels are running one direction, the whole rear axle try to rotate in an opposite one (the model "push up" when going forward and "push down" when going backward) because there is not enough weight behind the pivot point. So no matter the shock used the dynamic stiffness of the rear axle is basically the same, it needs to fight the wheels torque instead of just the model weight.

Then how can we get an actually working rear suspension while staying close to the original model form factor ? Well, by making the rear axle move in a way that it would be basically not affected by the wheels torque.

With that in mind I've ended up with a 4 links "live axle-ish" design, just around 1 stud longer wheelbase than the original and 10g heavier. It has a way longer vertical travel and can even go for pendular moves. More important is the fact that now it can run soft in every situations since there is no more axle rotation to affect the suspension stiffness. The axle is kept in the center by the shock itself (9.5L dark-grey, from my 8880) since I didnt find a way to go for a panhard bar, but it still works quite well since the lateral play is very light. The pendular move is possible because there is only one shock in the center and his attach point can flex a bit and is strong enough to not popping-off under stress.

The general stiffness of the moded suspensions (front and rear) is tweaked to have a good terrain sensitivity, it can handle little jumps too (ground clearance fully compressed is about 1 stud).

 

 

[Jurss]

Built this from my parts. I dont have that new beam. And it is really not neccessary for this set. Don't know why they really introduced that new beam with this set.

As I had only one L-motor, put XL for drive. Of course first surprise (stupid me) was, that control+ didn't liked it. Then I switched to topgear car, needed to reconnect that xl motor to C outlet. Also, D and R are reversed. It is just not enough to use R for D or vice versa, as R is not so fast. It means, that rear assembly (axle) needs to be mirrored to have some good speed.

[AVCampos]

2 minutes ago, Jurss said:

I dont have that new beam. And it is really not neccessary for this set. Don't know why they really introduced that new beam with this set.

I don't think anyone's complaining, though. That kind of beam has been sorely missed by fans for a long time!

[Jurss]

Yes, it was needed, no complains, but it was really not necessary for this set. Yes, it somehow improves look, as now I have some 2x4 L beams on sides.

[User5346]

Tempted to buy this set as is not showing on LEGO.com? 

[Malek83]

I can confirm that it went missing from LEGO.com official shop in Poland along with Volvo 6x6. So as a precaution I bought mine from Amazon.pl for around 86 EUR (shipping incl.) yesterday.

[User5346]

Hypothetically, if LEGO has decided to remove this set from sale (retire it) would they discontinue it completely or do an updated version (assuming the current battery box is the issue)? Credit to RacingBrick on YouTube as I wouldn’t have noticed!

[mpj]

If it was currently out of stock, it should be listed as "out of stock" and not completely disappeared, the same for the Volvo hauler.

Very strange.

[TechnicRCRacer]

It’s been removed from USA LEGO webpage, I bet it’s to switch manufacturing to the new battery box.

[JaBaCaDaBra]

Maybe some didn't notice but the Technic hub has disappeared from LEGO's website too.
So we have our answer.

Edit:
Hmmmm, but the 42100 however (containing 2 Thubs) is still there.

Edited July 6, 2021 by JaBaCaDaBra

[Malek83]

Liebherr ,Crawler 4x4 and Top Gear Rally Car are still there.

[JaBaCaDaBra]

52 minutes ago, Malek83 said:

Liebherr ,Crawler 4x4 and Top Gear Rally Car are still there.

Yep,
so either they allready added new safer hubs to these sets or we are completely wrong.
Or... last try, could the age indication have to do something with it?

Edited July 6, 2021 by JaBaCaDaBra

[Malek83]

1 minute ago, JaBaCaDaBra said:

Yep,
so either they allready added new safer hubs to thse sets or we are completely wrong.
Or... last try, could the age indication have to do something with it?

What were the issues with battery box? Maybe I have missed this information.

[JaBaCaDaBra]

1 minute ago, Malek83 said:

What were the issues with battery box? Maybe I have missed this information.

It can be opened too easy by kids.
They added screws to it in a new version.

[Malek83]

1 minute ago, JaBaCaDaBra said:

It can be opened too easy by kids.
They added screws to it in a new version.

Ah...ok. I thought it would be about the electronics or something :-)

Thanks JaBaCaDaBra :-)