[WIP] ROPA Tiger 6s beet harvester

[MP LEGO Technic creations]

The motorbike contest is over so I managed to make some new progress (the biggest succes is the belt from rubber parts now runs smoothly enough not as in previous versions):

 

 

I also started to mount pneumatic hosing....I'm not 100% satisfied with that but it's OK now.

And a photo from the underneath:

Thank you for visiting!

[MP LEGO Technic creations]

Hi everyone.

It has been a while since the last update of this project has been posted and some things have changed.

I decided to not to build the Panther 2 (I'm sorry) but the larger one, the Tiger 6s, which in conclusion means adding an extra axle and reworking some parts of the machine.

Current features:

Drive by 3 C+ XL motors (1 per axle)

Front wheels steering by 1 Spike Prime medium angular motor

Articulated steering uses the C+ L motor

Each of rear axles steered by C+ large angular motor (no.15), 2nd axle connected to the "pedestrian safety mechanism" (I don't know how to say it better)

Pendular rear axles 

"Harvesting" motor already placed, but connected only to the front belt (between front wheels)

Some moving details in the interior

In total, there are 8 motors now (next 5 or 6 are about to come ;-) and 3 hubs (2 C+ smart hubs and one train hub, one C+ hub will be added)

Some photos (sorry for quality):

 

 

 

 

Here's how the medium angular motor's mounted.

 

The train hub is hidden, but the box is still bigger than the original one.

And finally, the biggest problem faced so far - the Powered up app (which isn't even supported on my phone now).

The problem is that when the machine is in the "all wheel steering mode", both rear axles turn in different angles (as well as in every vehicle with more than 1 steered axles),

but when the vehicle is in the "crab mode" the rear axles turn same.

Bacause I'm not very good at programming, the best solution that came to my mind was to limit the speed of one motor when "all wheel steering" is engaged.

The downside of this solution is that you have to return the wheels to the middle before changing a steering mode 

Could someone with more knowledge about the Powered up app help?

Thank you all for visiting & comments are welcome.

Edited September 9, 2021 by MP LEGO Technic creations

[Milan]

Nice update. Glad to see the new progress
Love all the brick built sections, given the size, it is possible to put a nice amount of details and realistic proportions. Will follow this.

Please reduce your image size (max is 1024).

[efgen86]

Wow, a very interesting and beautiful project. The combination of articulated steering and classic steering looks cool. The number of features planned is impressive. I wish you a successful completion of the mock and will follow the progress with interest.

[Mike D]

Off topic but gotta love how non-military equipment company has models called Panther and Tiger

[Axadder]

A really beautiful model and also a really beatiful Lego model implementation.

I´ll follow your evolution, I really like it.

[MP LEGO Technic creations]

7 minutes ago, Mike D said:

Off topic but gotta love how non-military equipment company has models called Panther and Tiger

And let's not forget the Maus 

[Andman]

3 hours ago, MP LEGO Technic creations said:

The downside of this solution is that you have to return the wheels to the middle before changing a steering mode 

What happens when you switch the mode without returning to the center?

[Void_S]

@MP LEGO Technic creations, as a programmer (I definitely love separating my work and hobbies) I personally would try to make these steering modes mechanically:

1. "Crab mode" = all rear axles + front section are turned at the fixed angle.
2. "Small steering" = only rearmost (a little) and foremost axles are rotated.
3. "Full steering" = all rear axles + front section + front axle are turned at different angles.

So, I would make two steering systems:

1. Line #1: Front section + middle axle + A-input of "steering subtractor" at the rear axle.
   Using only this line you will have a "crab mode" steering.
2. Line #2: Front axle + B-input of "steering subtractor" at the rear axle.
   Adding some rotation to this line together with line #1 you will additionally turn the front axle and turn more the rear axle, so it will have a bigger angle rather the middle one.

* The "steering subtractor" here could be made as a differential with two inputs (steering lines) and one output.

Added: I realize that it is an incredibly difficult scheme and I have never seen something similar in any of the existing MOCs but it looks very technic-ish variant ever 

Edited September 9, 2021 by Void_S

[2GodBDGlory]

I like it! I think this is the first model I've seen to use quite so many hubs! Fortunately you seem to have space for them all...

Powered Up isn't supported on my phone anymore either.

[Andman]

Here is my approach:

The motor connected to B changed it's position when i switched the value for a. I'm wondering why you aren't using the steering blocks for... well... steering :-)

[MP LEGO Technic creations]

@Andman I have just tried yout solution and here's my experience with it.

I looked to your photo and carefully recreated the same program in my app, but even there's no mistake, it can't work as described.

After some tries I realized that evyrything works well, except "the steering blocks" (that's why I don't use them at all).

Then I switched the "steering blocks" to the speed control ones and everything is OK, now it can control the speed of both motors (and it works same as my own idea, but seems to be easier).

In conclusion, I really don't know what's wrong with the "steering blocks", they ignore slides and joysticks, as well as the stop button. The motors just rotate and can't be stopped ;-)

Anyway, thanks to your suggestion, which at least simplifies my own one.

Edited September 10, 2021 by MP LEGO Technic creations

[Rebel_Lego]

Did you connect the steering motors to the steering shaft/rack? The motor wants to find its endpoints, so it needs to calibrate. It first spins to one side, and if it finds it’s endpoint, it spins to the other side. If it doesn’t find one, it just keeps spinning. I had the same problem with the PU motor spinning when I first build something with it. It’s a shame TLG didn’t offer more documentation on how to use the PU motors and app, but that’s another discussion.

Btw, I really like agriculture machines (either real or in Lego version), and I love this one. Great eye for detail, and also many working functions.

[MP LEGO Technic creations]

@Rebel_Lego Oh, you're right.

Even though, there's a problem. The rear axles use worm-gear-operated gear racks, which is, at the end, quite a big reduction (to handle the model's weight) and calibration process still thinks, that it isn't at the end yet, which almost caused planetary gear reduction damage (tries to stop it manually ended up with some minor injuries ;-).

I'm definitely impatient enough to calibrate (four different motors) even when switching from "programming mode" to the "controlling mode".

Articulated steering uses 2 small LA, which also don't affect the calibration process at all.

However, nice to know, how the steering blocks actually work 

 

Edited September 10, 2021 by MP LEGO Technic creations

[Andman]

1 hour ago, MP LEGO Technic creations said:

I looked to your photo and carefully recreated the same program in my app, but even there's no mistake, it can't work as described.

After some tries I realized that evyrything works well, except "the steering blocks" (that's why I don't use them at all).

Hm, are the motors for the steering supposed to act like servo motors (automatic return to center) or like in the 42070? While there are some bugs in the Powered UP app, i never had any issues with the steering block.

Could you explain how you steering system works?

[MP LEGO Technic creations]

@Andman This problem was already solved (I tried loose motors, not connected to anything), but now there's an issue with calibration, because of some gear reductions (please see my previous post).

[Andman]

6 minutes ago, MP LEGO Technic creations said:

@Andman This problem was already solved (I tried loose motors, not connected to anything), but now there's an issue with calibration, because of some gear reductions (please see my previous post).

Sorry, didn't see the mentioned post. did nor reload the page

But now it makes sense. You aren't using a return to center steering. That makes several things more complicated. I would strongly recommend to use some kind of clutch to prevent damage, if you would like to keep you current steering mechanism. But if possible, change it to return to center steering (motor as a servo). That way you can easily switch between steering modes.

BTW, really great project. Looking forward to see more progress!

[MP LEGO Technic creations]

So, after a very long time, I've made some worth-to-share progress.

When going from the front, these are the most important changes (among the bodywork):

• Pneumatic cylinders for lifting the front unit changed to small LAs operated by a PU L motor hidden in the front part (just underneath the cabin)
• Front wheel steering is done by a small angular motor (from SPIKE Essentials, BL id here)
• I've got rid of the train hub next to the cabin and replaced it with a standard C+ smart hub located behind the cabin (very easy replace of the batteries)
• Placed a pair of LED lights at the front (as well as at the back)
• Cleaning sections have finally been built! (rubber-band-driven)
• The elevator belt and areas around have been changed a lot, the belt now runs very smoothly (very satisfied with this), while it still can carry 1x1 round bricks towards the bunker
• Quite an effective unloading system

There's much more of course, however as the last update was almost a year ago, I've already forgotten what's new and what isn't 

Anyway, thanks for reading, hopefully the next update will be sooner.

 

 

 

 

 

 

 

 

 

 

 

 

 

And of course a shot from underneath 

 

Edited April 13, 2022 by MP LEGO Technic creations
completely forgotten about the rear LED lights

[Jurss]

Interesting and challenging machine. Great job so far.

[Maaboo the Witch]

Woah, this thing is built to beet! 

[MP LEGO Technic creations]

1 minute ago, Maaboo35 said:

Woah, this thing is built to beet!

Yep, it's planned to be fully working (it's already now if you don't mind loosing most of the harvest during its way into the bunker - still missing some working parts ).

[Leonardo da Bricki]

Wow. That's quite a lot of progress. I'm excited to see the harvesting head and how it functions. The brick-built color scheme is cool. Keep up the good work! 

[shroomzofdoom]

Fantastic work!  

PS-two pages and no Dwight?

 

[Maaboo the Witch]

[MP LEGO Technic creations]

In case there's someone who'd like to know some further progress on this one.

As quite a long time passed from the last update, a lot of things were added/changed since then (I need to sum up the changes in my mind a bit )

Meanwhile I've taken a shot for comparison with a real beet, hopefully a photo with the real machine will be taken one day...

A proper update will come in the next week, sorry everyone and thanx for patience!

 

Edited November 10, 2022 by MP LEGO Technic creations