[TC22] Clamshell dredger

[JoKo]

Hi everyone! This is my first appearance on Eurobricks. I hope you'll like my interpretation of a construction vehicle. As professional boatbuilder I choosed to build a floating machine.

The platform is made with the 42105 catamaran hulls, using black stickers for fixing leaks and colour matching. 

The main feature is the dredging crane. The main twin winch operates the clamshell. With a single hand knob it automatically opens the shell before going down and closes it before lifting. The mechanism is simple and located between the big gears. Another winch and hoist adjusts the crane arm elevation.

The boat is motorized with 1990's PF motor, switch and 9V battery box. A powered fixed propeller is hidden between the hulls and a steerable ducted prop allows maneuverability and looks like a Z-drive propulsion. However the boat is too heavy and unbalanced to float property without additional buoyancy.

 

Best technic regards

 

 

And some outdoor pictures!

I had to use wheels to help buoyancy and stability on the water. Of course it exceed the 10 000 limit but look at this, I had to share the photos.

 

 

 

Edited May 16, 2022 by JoKo
outdoor pictures

[Akassin]

Welcome to Eurobricks!
It's rare to see ships on the Lego Technic forum. And your building looks great and I think it would be very interesting for a child to play with it . Very original use of caterpillars!
Did you make this building specifically for the competition? If so, what is the overall size of the box? I could be wrong, but I think it's more than 10,000 studs. If not for the competition, then it is not necessary to add [TC22] in the title of the topic.
In any case, I would like to see more photos. Great job! 

[1980SomethingSpaceGuy]

Welcome to EB!
Very nice model, we don't have enough boats around here. 
I like the winch two-in-one action. And the anchor!

Edited May 16, 2022 by 1980SomethingSpaceGuy

[JoKo]

1 minute ago, Akassin said:

Welcome to Eurobricks!
It's rare to see ships on the Lego Technic forum. And your building looks great and I think it would be very interesting for a child to play with it . Very original use of caterpillars!
Did you make this building specifically for the competition? If so, what is the overall size of the box? I could be wrong, but I think it's more than 10,000 studs. If not for the competition, then it is not necessary to add [TC22] in the title of the topic.
In any case, I would like to see more photos. Great job! 

Thanks, Yes I made it for the competition.

The folded size is 19x14x37.5 = 9975 cubic studs, I had to scratch my head a few times to keep it in the box.

Some details are a bit fragile, it would deserve a more sturdy version to let small children play but the clamshell mechanism is fun to play with.

[Akassin]

10 minutes ago, JoKo said:

Thanks, Yes I made it for the competition.

The folded size is 19x14x37.5 = 9975 cubic studs, I had to scratch my head a few times to keep it in the box.

Some details are a bit fragile, it would deserve a more sturdy version to let small children play but the clamshell mechanism is fun to play with.

Now that I have seen the new photos, this model seems even more incredible to me. Because it looks HUGE when unfolded and I couldn't believe it could fit in a 10,000 box. Amazing! 

[GerritvdG]

Welcome to Eurobricks! Really original, I always wondered what to build with those catamaran hulls, well done!

[howitzer]

Very nice and original interpretation of the contest theme!

[SaperPL]

Amazing, especially the idea to collapse it all like this thanks to it being rope-based.

I really like the idea of using the tracks on the sides, great job on this trick.

[JoKo]

3 hours ago, 1980SomethingSpaceGuy said:

Welcome to EB!
Very nice model, we don't have enough boats around here. 
I like the winch two-in-one action. And the anchor!

Thanks mate!

good idea to let me know about this contest

[1980SomethingSpaceGuy]

A pleasure! Nice update with the outdoor photos above! 

[Maaboo the Witch]

Very unusual! Cool stuff. Great job with the photos as well.

[JoKo]

Thank you to everyone.

I also made a small video

 

Edited May 17, 2022 by JoKo

[SaperPL]

Do you have some WIP photos of the process maybe?

On 4/8/2022 at 8:07 AM, Jim said:

• A discussion topic needs to show some actual progress (i.e. pictures of the build in progress) and should not be used to "reserve an idea".

 

[JoKo]

25 minutes ago, SaperPL said:

Do you have some WIP photos of the process maybe?

 

I do! but a few...

[JoKo]

13 hours ago, SaperPL said:

Do you have some WIP photos of the process maybe?

 

Ok, you're right. I will detail the story.

So the base is the catamaran hulls and this picture: (higher resolution on wikipedia)

 

I was disapointed with the  hulls, massive leaks when loader but electrical tape will fix that and hide the light green part.

The main challenge was the 10 000cs rule. The hulls with tracks and light gray platform are half the volume when 1 stud between the hulls (37.5 x 19 x 7 =4987.5cs ) I had to keep everything in the same footprint and max 14s high. The tracks are in tension by the shape of the hulls, with inverted bows. One single pin on each centerline and the platform keep them in place.

The crane design is quite simple. A long main beam and a shorter one at the back with the hoists. The twin winches are delayed with a simple mechanism. Both are connected to a big gear with two pins each. The main winch is hand activated and the secondary one is delayed by half a turn of the big gear (not quite) and 1.5 turn of the winch. Friction pins avoid unwinding when not wanted.

I had to buy a second 42116 loader for the clamshell. 30433 was more on scale but Hey, that's a dredger and not a sugar cube picker!

 

When the crane is operational it's time for the first sink test. Stability is awfull with the oscillating weight, just a bit better with the clamshell touching the water. The waterline is already too high especialy at the bow (the aft of a boat (the crane side obviously!)) At this point I know it would never float properly without extra lift, well over 10000cs. I continue with a display playable model but i keep the idea of electrical powered propeller for sailing extras. The vintage 9V motor is perfect for the small prop. Not much torque but high revs!  Not much space between the hulls. I coudn't find a way to fit a proper Z-drive ( steering with the prop) so I keep it simple with a straight propulsion and a ducted steering free-rotating propeller in the flow. The HOG is just over the propellers.

Everythig else is making things pretty and adding minifig scale details with a 14studs gauge in the other hand. The last element to find it's place is the boat cabin with fonctional compass, flush with the track on starboard, in the last bit of space aviable with the crane folded. The crane can rotate 360°.

I added sailing equipment mixing technic and system: 4 mooring bollard, anchor, sailing lights, horn, life buoy, compass and crew!

I had a realy good time with this project. Minifig scale technic is fun and it was a pleasure to play with my childhood's shark for the video!

Edited May 18, 2022 by JoKo

[SaperPL]

10 hours ago, JoKo said:

Ok, you're right. I will detail the story.

Well, my point was that this is genuinely one of the most creative approaches to the limitations, and at the same time I believe one of the reasons for a build thread was to not allow people to just lurk until last moment and drop huge expensive MOCs right before the deadline, and also there is a potential in some of the contests for people to just by sheer luck roughly meet the theme with what they've been preparing for a lot longer than just the contest period. For some of previous contests, if I remember correctly, you had to have a thread added at least halfway before the deadline, but my memory may be wrong here.

Anyway, since I'm pestering moderators a lot about keeping up the game fair and vetting the entries against the rules before voting, I was just making sure there's no room for accusing this entry for foul play here :)

[Jim]

On 5/16/2022 at 2:55 PM, JoKo said:

The folded size is 19x14x37.5 = 9975 cubic studs, I had to scratch my head a few times to keep it in the box.

Very nice entry!! And welcome to EB. For the entry topic you need to provide an image with some sort of bounding box, so we can verify the dimensions. Make sure to include one.

Looking forward to seeing more of your MOCs.

[JoKo]

22 hours ago, SaperPL said:

Well, my point was that this is genuinely one of the most creative approaches to the limitations, and at the same time I believe one of the reasons for a build thread was to not allow people to just lurk until last moment and drop huge expensive MOCs right before the deadline, and also there is a potential in some of the contests for people to just by sheer luck roughly meet the theme with what they've been preparing for a lot longer than just the contest period. For some of previous contests, if I remember correctly, you had to have a thread added at least halfway before the deadline, but my memory may be wrong here.

Anyway, since I'm pestering moderators a lot about keeping up the game fair and vetting the entries against the rules before voting, I was just making sure there's no room for accusing this entry for foul play here :)

I understand. It's just that I'm new to this and was a little shy to share an unfinished MOC. Thanks for caring about my entry is legit and unsuspicious

If anyone has a doubt that I started this project for the contest, my good friend 1980SomethingSpaceGuy told me about the contest the 15th april, I have proof!

3 hours ago, Jim said:

Very nice entry!! And welcome to EB. For the entry topic you need to provide an image with some sort of bounding box, so we can verify the dimensions. Make sure to include one.

Looking forward to seeing more of your MOCs.

Mr Administrator himself! Nice to meet you .

The bounding box picture is posted, does it seem legit to you? I can make more if needed

You won't have to wait much to see my next MOC presentation!

[Jim]

40 minutes ago, JoKo said:

I understand. It's just that I'm new to this and was a little shy to share an unfinished MOC. Thanks for caring about my entry is legit and unsuspicious

If anyone has a doubt that I started this project for the contest, my good friend 1980SomethingSpaceGuy told me about the contest the 15th april, I have proof!

No worries, you're good!! 

42 minutes ago, JoKo said:

The bounding box picture is posted, does it seem legit to you? I can make more if needed

That's perfectly fine!