Practice English Speaking&Listening with: Real automatic transmission for LEGO Technic 42114 6x6 Volvo + custom controls with BC2

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What's up guys, this is Balazs from RacingBrick!

The 42114 6x6 Volvo Articulated Hauler supposed to have an automatic gearbox in the Control+

app which in reality only works in one direction, it shifts up automatically but does not shift


At least this is the case in the beta app, so I decided to upgrade it a little bit, but

more about this later.

The official release date of the set is the first of August so there's no final Control+

app available yet, but as it showed up already in some stores there're folks out there who

built it but cannot control it without an app.

The Powered Up app did not receive yet a support for the Technic Large Angular motor in the

latest update so there's no way to create a control profile for it in the official app.

I suggest to use BrickController 2, even with that the setup is not trivial due to the remote

controlled gearbox but here's a fairly simple setup.

All of these steps are documented with photos on my blog, click on the link in the top right

corner or in the description to access it.

We need to calibrate first the L motor that controls the gearbox, I created a separate

profile for that.

It has a single controller setup, it rotates the motor by 5 degrees each time.

This can be used to rotate the gear indicator to the position of the 1st gear, as close

to the 90 or 0 degrees position as possible.

Once you have it you can switch to the control profile, as I said the setup is documented

in my blog post.

In this profile we can use the left joystick to control throttle, and 2 buttons to switch

between gears, the right joystick controls the steering.

There's no automatic shifting this time, make sure to wait until the motor switches to the

next position as you can mess up the position if you tap the buttons to quickly.

If the gear selector motor gets misaligned then you need to re-calibrate it with the

other profile.

As you see you can switch between the 3 driving gears, and the 4th position will be park where

you can tilt the bed.

I removed the bed to have a better visibility on the gears this time.

Another suggestion, stop the truck between gear shifts, that puts less stress on the

whole gearbox.

So, back to that automatic transmission!

As you remember the hauler has 3 gears and it shifts up automatically as you push the

joystick forward.

This works on a flat and smooth surface, but in 3rd gear practically any obstacle will

stop the vehicle as you can see here.

If you keep pushing the joystick forward then the hauler simply stops but it won't shift

to 2nd or 1st gear.

You need to release the joystick, then it'll automatically shift back to park and then

it starts again in the first gear and it can successfully climb the obstacle.

Even a simple pencil can stop the hauler in 3rd gear, you need to stop and then start

again in 1st gear to climb over it.

This control method is usable, but I wanted to see if we can use the advanced abilities

of the Powered Up system to create something that works more like a real automatic gearbox.

Since the Technic large angular motor is not supported yet by the Powered Up app, I had

to replace it with the Spike Prime variant.

Hopefully we will get an update soon with proper support.

The code is experimental and very much work in progress, I'm not sharing it yet as you

can only use it with the Spike Prime motor for steering anyway.

I'd like to wait for the final Control+ profile as well to see if anything similar is implemented,

if not then this might be interesting enough to develop further and publish.

So, here's how it works currently - there's a calibration sequence at the beginning, it

rotates the axle in the position of the first gear.

Once the calibration is finished the hauler starts in 1st gear.

The whole sequence is slowed down to ensure a smooth operation and to do the tests, it

can be quicker in the future if it'll be reliable enough.

If the speed of the driving motor is high enough then it shifts to the next gear, but

the motor stops during shifting to prevent any lockups.

If the motor slows down due to the lack of torque then the app will automatically shift

down, slowing down the hauler but also providing more torque.

Now let's see the previous scenario!

On flat surface it shifts up gradually, similarly to the Control+ profile.

If there's an obstacle then there's no need to release the throttle, the code detects

the stalled motor and it shifts down until the hauler starts moving again.

Downshifting also works if there's a possible jam in the gearbox and the driving axle cannot

rotate properly.

Now let's test it outside!

As you see on a moderately smooth surface it runs well and it'll shift up to 3rd gear.

When it reaches the pebble it stops, shifts down to 2nd and then to 1st and then climbs

it successfully.

Once the motor has less resistance it shifts up again.

On the grass it stops completely in 3rd, shifts down to second and then to first gear.

At this point some fine tuning is needed as the power difference is too big between the

first and the second gears, it is difficult to detect if the torque required is only available

in 1st or it is ok to shift up to 2nd gear.

There's another feature I implemented - since the hauler can only climb any incline in first

gear, I used the hubs built-in gyroscope to detect if the hauler is going upwards.

In this case the gearbox won't shift to second, even if there'd enough speed to do so, it

stays in 1st gear.

This is a very steep incline, almost at the limit of the hauler but it can climb it slowly

in first gear.

Once it reaches the top the code again permits shifting up so it can go forward.

So, this is my current implementation of an automatic gearbox control, let me know in

the comments what you think about it or what additional features could be added going forward.

I'll do another video about the set with the official release of the Control+ profile and

we'll see if there's a need for a more sophisticated custom control :)

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See you next time, bye bye!

The Description of Real automatic transmission for LEGO Technic 42114 6x6 Volvo + custom controls with BC2