Hi everyone, my name is damien and in this video I'm going to try to get my Lego Tunnel Boring
Machine to dig through a block of snow. If you haven't seen my original video about the Lego TBM,
you can check it out on the link below.
I don't know how this is going to work out. On one hand the cutter head is not really the strongest.
However, snow might be the perfect medium as it holds its structure and itself is not very strong.
I got the idea of snow from all the comments in my original video, so thanks a lot for those.
Right now I'm going to head out, get a chunk of snow, and I'll see you in the garden.
All right here we are. We're ready to go and we have a fresh set of batteries
in the TBM. We have our block of snow. Now we just need to fire it up.
Good luck buddy!
Here we go! The linear actuators are extending, pushing the cutter head towards the snow block.
Okay, now it's starting to make contact and it's starting to scrape away at that snow block.
Here's a view from above and you can see the snow getting scraped away on the left, using
those headlight pieces from the original bucket wheel excavator set that i have fashioned as
diamond cutters for the TBM. Now in fast forward so we can see it crunch away at the snow block.
I've added a brick to keep it stable. It was
getting caught at the bottom and wanted to move sideways.
Crunching away, crunching away.
So here's the damage after this first attempt. I decided to stop because the cutter head was
getting stuck at the bottom right, where the snow block was melting and that layer,
that dark layer, you see there is starting to act more like ice and less like snow.
And the Lego TBM just doesn't cut it when it comes to ice.
So for the next attempt I'm going to raise the platform which the TBM is on and try to
cut higher above that partially melted part so it's just digging into snow. Here we go again!
So I've decided to call it quits after this second attempt because we're not making much progress.
Scraping the surface of the snow block,
I could tell that the snow has melted too much and it's becoming a little bit more like ice,
and it's harder and harder for the TBM to dig through it. I'm starting to lose hope
on this project but because this particular snow block has melted so much, i'm going to try one
more time with a fresh snow block and get digging right away, as soon as it's made.
Here we go again!
Here's a view from beside the TBM where a small pile of snow is starting to be formed,
as it digs through the snow block.
After about 20 minutes, it's time to call it quits on this third attempt.
Here's a look at how much the TBM was able to scrape off that front face,
but in reality we didn't make it more than about five millimeters into the snow block.
So what happened? Well the snow block acted more like ice, than snow, and that was really the root
cause of why I wasn't able to dig through my block of snow. Mechanically, the weak point of
the TBM is actually the worm gear, and when the cutter head was getting stuck in the snow block,
the worm gear would actually skip and make this really awful clicking noise. And this is despite
having clutch gears in the drive system itself, although I am using three clutch gears in parallel
to give me three times the torque. As you probably saw in some of those clips, what I also was doing
was applying additional torque to the cutter head manually, especially during the third attempt,
to try to get me through the snow block. And even when I was manually adding a little bit of force
using my hands, there was still a ton of resistance from the from the snow against the
cutter head. So even if i improved the gearbox and prevented the worm gear from clicking or skipping,
the clutch gears would eventually clutch and the cutter head would be stuck, or the motor would
would eventually stop rotating. So honestly, I think my snow block wasn't the right
medium for this test and we'll have to try something else another time.
Now before I end this video I might as well share with you some of the cool shots I had
planned with the side dumping dump truck and the Volvo A60H. Enjoy!
That's it for this video. The TBM will be back. Thanks for watching!