(MOC) sennebogen 880 eq

[Oliver 79]

Hello all.

This is my latest MOC (fail...) The Sennebogen 880eq.

This has been in the making for quite some time now. Today I decided to call it finished. Unfortunately, It is a bit of a fail.

Technical parts involved,

• 5 x PF medium motors
• 2 x AA battery box
• 3 x PF IR reciever
• 4 x Large liner actuators

Motorized functions,

• Motorized tracks (2 x PF medium motors)
• Arm movement (2 x PF medium motors)
• Top super structure slew (1 x PF medium motor) - FAIL.....

I was pretty happy with the over all looks of the model. Here's the picture I used,

As for the functions. Well, that's where the problems are!

The tracks work well, and I was surprised the medium motors could cope with the weight of the model. The arm works ok, but the range of movement is way too limited. The last function, the slewing didn't work at all. Unfortunately the weight of the model caused too much friction on the turntable. I used the old stye one as it fitted together better given the studded nature of the model.

I even tried a bit of oil, which goes against everything I stand for!

It's a shame because it took ages to come up with a mechanism to fit inside the main column. oh well.

Here's a couple more pictures and a short video of the functions.

You can see my arm trying to help with the slewing just before something inside broke!

Here are a couple of shots of the internal workings,

Thanks for looking. As ever, constructive criticism most welcome.

 

Edited January 21, 2018 by Oliver 79
Pictures of internals added.

[JGW3000]

Awesome effort, really looks great.  Shame about the slewing, perhaps some small wheels would have helped?

[Aventador2004]

Looks nothing like a fail!

[Oliver 79]

13 minutes ago, JGW3000 said:

perhaps some small wheels would have helped?

Thanks. I did try a few methods with wheel. Unfortunately due to size a part constraints, I couldn't make it work.

[doug72]

Looks good, shame it had problems with slewing etc. Might be more reliable if built with studless technic.

The old studded turntable has a lot of friction, the new z60 turntable are much freer.

[suffocation]

I wish my countless Lego fails looked even just one-hundredth as good as that.

How much did you gear down the M motors on the tracks?

[BrickbyBrickTechnic]

I wouldn't consider that a fail. Seriously, it looks so nice! Nicer than my fails by a very, very, long shot 

[Oliver 79]

1 hour ago, suffocation said:

How much did you gear down the M motors on the tracks?

According to sariel's gear ratio calculator 1:20. 

Thanks for the replies.

Just to clarify why I think it was a fail. The functions didn't work as planned. Also, just after I shot the video, it pretty much fell apart due to the weight of the arm. Unfortunately I couldn't make the weight evenly distributed. The counter weight at the back housed one of the battery boxes, but it still wasn't heavy enough for even ballance. This in turn caused the whole top structure to be unstable. The 4x4x6 round wall pieces used for the main body just couldn't handle the weight. 

On top of that, I couldn't come to a compromise between weight and rigidity for the arm. I had to press the pieces back together after I moved the model every time. The last demonstration in the video was all it could take, and it just broke! 

So on many levels the project was a success. It looked good and I enjoyed building it. But overall, it just didn't live up to my expectations. 

But watch this space, I'm sure MK II will come at some point. 

 

[mocbuild101]

7 hours ago, BrickbyBrickTechnic said:

I wouldn't consider that a fail. Seriously, it looks so nice! Nicer than my fails by a very, very, long shot 

I agree, it might not be perfect, but it's nowhere near a fail!

[MangaNOID]

very happy you showed this even if it didn't work right. Its a really interesting machine to build, I haven't seen one like that before. we await MKII 

[doug72]

11 hours ago, Oliver 79 said:

The counter weight at the back housed one of the battery boxes, but it still wasn't heavy enough for even ballance. But watch this space, I'm sure MK II will come at some point. 

 

 

On my crane MOCs if a large battery boix is insufficient as a counterweight I use a 8878 battery box with the internals removed and replaced by steel or lead weights with the top of the housing disguised.
Your MOC looks excellent but as per another topic aesthetics v technic is at work or Studfull (prone to pulling apart) v Studless which provides a stronger structure.

Its a compromise with any technic build.

Look forward to seeing a Mk 2 version - had a look at the Sennebogen website and there are a number of cranes that ideal for Technic builds.

[Oliver 79]

@Doug72 that's not a bad idea with the weight. I did consider boat weights, but your solution would be more compact. 

As for the aesthetics vs technic discussion. I learned a lot about the limitations of studded Lego. It's very difficult to strike a ballance between the two. 

And yes, there is a whole world of inspiration on the sennebogen website!