[MOC] Rocky 42099 B model

[Didumos69]

1 hour ago, kbalage said:

@Didumos69 you're very welcome, thank you for the great design! I was very lucky with the weather, we had the last warm days of autumn and the Danube's water level was low enough to approach this area, otherwise it's usually under water. Let me know if you decide to come here and I'll show you some other great spots to explore (with LEGO RC cars of course )!

Just watched it again. I like the section starting at 4:00 the most. Is suffers, but manages.

(new page, so embedded it again)

Edited October 29, 2019 by Didumos69

[Didumos69]

@kbalage, I think I will add the diff locks as an option to the instructions. If the locks can do without the half bushes, it can actually be done with the stock 42099 parts list by moving a few things around.

[agrof]

Very cosy video @kbalage, also like the improvement in your editing style! Who knows, maybe soon we will see a full evening Technic movie from You... 

@Didumos69 I am still in awe by this B-model (I just love extreme off-road vehicles), especially the diff locked version seems very capable. Visit in Hungary - please let us know, we will make good things happen than! 

[kbalage]

@agrof thank you, a full movie would be tough but never say never 

@Didumos69 probably you could add it as a remark/extra option, if someone wants to use it as a hardcore offroader with locked diffs I'm sure that person has a few extra pieces  Using it as a real rock crawler has its consequences anyway so spare/replacement parts are definitely needed:

 

[rekreK]

14 hours ago, Didumos69 said:

@kbalage, I think I will add the diff locks as an option to the instructions.

Lockable diffs that can be easily opened would be the best.

Like a manual lever either end to lock and open them when needed

[Didumos69]

9 hours ago, rekreK said:

Lockable diffs that can be easily opened would be the best.

Like a manual lever either end to lock and open them when needed

You are right, but I don't see anything like that possible within the other parameters such as a pre-defined parts list and compactness of the axles (ground clearance, front and back clearance, i.e. the tires need to stick out to the front and to the back). So I'll stick to the option to build it with open or locked differentials.

16 hours ago, kbalage said:

@Didumos69 probably you could add it as a remark/extra option, if someone wants to use it as a hardcore offroader with locked diffs I'm sure that person has a few extra pieces  Using it as a real rock crawler has its consequences anyway so spare/replacement parts are definitely needed:

Yeh, people probably have the parts needed to build it with locked diffs. But I saw a challenge in building it with locked differentials with only parts from the set and I found a way. I will simply add this as an alternative build track in the instructions.

Edited October 31, 2019 by Didumos69

[Didumos69]

Based on what @kbalage did in his video, I updated the instructions on Rebrickable. It now has two options: Option 1 with open differentials and options 2 with locked differentials. Both options stay within the parts list of the A model. People that already bought the instructions should be able to download the new version.

Edited November 1, 2019 by Didumos69

[Didumos69]

Btw, what a few of you might have noticed in @kbalage's video, is that it's hard to demonstrate the spring suspension while the model is standing on the ground. This is because when you compress the suspension by pushing down the cabin, the wheels rotate relative to their frames, which causes them to drive the motors. This is also why the model doesn't easily return up after pushing it down. When the model drives around, it easily returns to its ideal spring compression level, which is about 40% of the overall spring travel. To demonstrate or get a feel of the spring suspension, the best option is to lift the model with your hands underneath the front and rear differentials and let it bounce a little.

Edited November 1, 2019 by Didumos69

[Philo]

Finally took the time to write a few words about this model!
First, photo and video...

Rocky is very nice version of the crawler, with an innovative suspension system. As you can see on the video, the climbing capability is excellent. I liked a lot the photo steps building instructions (and from a LDraw aficionado like me, this is a big compliment ;) ). The model is compatible with LEGO app but works fine too with BC2 or Controlz. Some drawbacks now: accessibility to the "on" button of the hub is not wonderfully handy (but the procedure is well documented in the BIs). The wheelbase is 30% longer than official model, which means that the turning radius is very poor. Speed is slow too, the price to pay for the agility... but I dream of a model with a two speed gearbox controlled by a 4th motor!

Edited November 6, 2019 by Philo

[Didumos69]

Thank you @Philo, for sharing your experience. Great to know the instructions are workable. The model is slow, by design obviously, and yeh, the turning radius is quite poor. Maybe I have been too protective towards the new CV joints. I have been in debate whether to drop the levers tying together the upper and lower suspension arms (the black and yellow levers), but thought it would serve two goals, a stronger setup and a limited steering angle, which implies more protection for the CV joints. However, the model can do without the levers, because the tow balls and wheel hub are one piece (so now tow balls can pop out) and downforce is only applied to the upper suspension arm. Long story short, you might try to improve the turning radius by dropping the black and yellow thin levers close to the wheel hubs. You will also need to recalibrate the L-motor for steering of course.

Btw, I'm curious to know what you think of the rigidity/robustness of the whole model.

Edited November 6, 2019 by Didumos69

[rekreK]

Finished mine last night, I used whatever parts, so changed a few things including colors, but mostly stock.

Model is very solid and initial testing shows it performs well.

I would be interested in seeing how far this concept could be taken with the 'b' model shackles removed...
Combine the body suspension and articulation with traditional independent suspension in each corner, front and rear steering to create the "ultimate"

Edited November 8, 2019 by rekreK
added photos

[Didumos69]

10 hours ago, rekreK said:

Finished mine last night, I used whatever parts, so changed a few things including colors, but mostly stock.

Model is very solid and initial testing shows it performs well.

I would be interested in seeing how far this concept could be taken with the 'b' model shackles removed...
Combine the body suspension and articulation with traditional independent suspension in each corner, front and rear steering to create the "ultimate"

Thanks for your report! Yeh, also for me it felt like it could be brought further, but not with the constraints of this being a B-model. I am glad however, that the differential suspension ides, which is the core of the whole concept, is a success.

[Philo]

14 hours ago, Didumos69 said:

Long story short, you might try to improve the turning radius by dropping the black and yellow thin levers close to the wheel hubs.

The turning radius is indeed improved, from 105cm to 90cm. Nothing seems to suffer, as the limiting factor now becomes the steering rack range. Not tried yes to change rack length...

14 hours ago, Didumos69 said:

Btw, I'm curious to know what you think of the rigidity/robustness of the whole model.

Got absolutely no problem with that (but I have not tried outdoor/real rock run).

12 hours ago, rekreK said:

so changed a few things including colors

Awesome red livery! :)

[Didumos69]

34 minutes ago, Philo said:

The turning radius is indeed improved, from 105cm to 90cm. Nothing seems to suffer, as the limiting factor now becomes the steering rack range. Not tried yes to change rack length...

Nice! I would not go further. Gear rack travel is now at the level of the A model and I think LEGO was also careful with the max steering angle.

@rekreK, I can't see the images 

[alecmo99]

Awsome. Never thought about using the H frames positioned horizontally. Great job!

[Irom]

good job
your work is pure inspiration

[Didumos69]

13 hours ago, Irom said:

good job
your work is pure inspiration

Thanks you very much!

[PetSild]

Hi,

today I could focus on building the Rocky, the procedure is very clear and everything fits together.

The whole structure of the model me design captivated, creator must be a genius otherwise you can't explain, everything is so nicely thought out.

Mr Master Didumos69 a big thank you for the special B model.

[Didumos69]

Thanks for your kind words @PetSild! I'm happy you enjoyed the build!

[qasweder]

This 42099 was a christmas surprise. But this moc is much better than the original. THX. In this MOC i have some problems with the steering motor:
1. in the calibration of the control+ app the steering moves to both mechanical limits. after the calibration the steering is way of the center and does nor reach the mechanical limits. is there a way to set end points and center point manually?
2. I use eneloop accu in the controller, could this be the reason for calibration problem?
3. Is there an alternative app for controlling this central unit?

[Kn0bby]

I got the 42099 for Christmas as well..   Build the standard model on boxing day..  Not had any Lego for years..  Today I built Rocky!  

BuWizz app works with the control+.  If you have a go make sure you bind both drive motors!  On the standard model it appears to allow the steering to go beyond its limits.   

I had the same problem with the steering being off, I just pulled apart the front end and adjusted the center point, it seems better now. 

Back to Rocky..   Big shout out to @Didumos69 what a great design, it performs so much better than the standard model. Found the build trickier than the standard model which was a good challenge. 

 

 

 

 

[qasweder]

Thx Kn0bby, BuWizz works, but steering is not direct. I dont know the english words, but steering moves to the side, which you are directing with the joystick, and remains there, when you release the stick. This is not the way, i want to steer. I was not able to find an option to change steering mode. It is the original steering servo for 42099...

Edited December 29, 2019 by qasweder

[Didumos69]

@qasweder, @Kn0bby, thanks guys! I don't know about controlling 42099 with BuWizz app. To successfully calibrate the steering with the Control+ app, you may consider dropping the parts that form-lock the upper and lower suspension arms. Without these parts the max steering angle is exactly the same as for the A model and calibrating should behave the same too. This B model can actually do without these parts:

[Kn0bby]

On 12/30/2019 at 9:26 AM, Didumos69 said:

@qasweder, @Kn0bby, thanks guys! I don't know about controlling 42099 with BuWizz app. To successfully calibrate the steering with the Control+ app, you may consider dropping the parts that form-lock the upper and lower suspension arms. Without these parts the max steering angle is exactly the same as for the A model and calibrating should behave the same too. This B model can actually do without these parts:

Perfect. You are correct, full steering and it calibrates fine. 
 

Ever thought about combining this model and the 42110 Land Rover Defender? (Defender with bigger wheels, motorised!)
 

 

[Didumos69]

8 hours ago, Kn0bby said:

Perfect. You are correct, full steering and it calibrates fine. 

Great, thanks for letting me know this worked out fine 

8 hours ago, Kn0bby said:

Ever thought about combining this model and the 42110 Land Rover Defender? (Defender with bigger wheels, motorised!)

Not yet, but who knows?