[Epic Fail] Small Ring Crane

[Saberwing40k]

Good grief, this thing has been sitting on my desk for over a year now, and I just now got around to taking pictures of it. tsk tsk. Anyway, this is a failed attempt at making a ring crane using a hailfire droid wheel as a base. It is loosely based upon a Sarens SGC-120, and uses a 3 way reversable distribution gearbox, much like 42042. Each selector controls one function, forward and reverse. The crane features 3 winches, controlling the boom luffing, the luffing jib, and the hook. The winches are run by one M motor. The counterweight is 5 PF AA battery boxes, plus some old train weights, and some ball bearings. Now, I mentioned that this is a failed attempt, and there are a good number of reasons for that. Firstly, the gearbox connecting the M motor to the distribution box was very weak and overly complex. Then, this model had several critical structural flaws. The main boom wasn't nearly stiff enough, and would warp with the slighted provocation. The individual sections were  strong enough, but the connections to get them in a triangular shape were not. Then, the main frame of the crane was very weak, and bent a lot under the weight of the main boom. Same thing goes for the rollers on the base ring. They were not structurally sound at all, and due to that, motorized slewing was not possible. Lastly, the hook was not heavy enough to put tension on the hook line, and so the lines of rope going to the hook would jump at the slightest provocation. Still, even if this did fail, it looked impressive, and I learned from it.

IMG_20170813_202442189 by Saberwing007, on Flickr

The crane, in all of its glory.

Ring Crane 002 by Saberwing007, on Flickr

The gearbox. Each selector controls a winch.

Ring Crane 003 by Saberwing007, on Flickr

The M motor. This was one of the weak points of the model. Not the motor, but the gearbox it is attached to.

Ring Crane 004 by Saberwing007, on Flickr

The rollers. Not stable enough.

Ring Crane 005 by Saberwing007, on Flickr

The counterweights. There were two more battery boxes, but they got used for something else.

IMG_20170813_202804340 by Saberwing007, on Flickr

The crane base, without the booms or counterweight.

Ring Crane 007 by Saberwing007, on Flickr

The winches.

Ring Crane 008 by Saberwing007, on Flickr

The frame bending.

IMG_20170813_210407144 by Saberwing007, on Flickr

The gearbox extracted.

Ring Crane 010 by Saberwing007, on Flickr

The underside of the gearbox. It's dead simple, aside from the connection to the M motor, which was more complex than it needed to be, and would fail with minimal provocation.

Well, that's it. There will be no video, as this got demolished for my TC12 entry. Enjoy, as much as you can enjoy a train wreck like this.

[MattL600]

Very impressive and very ambitious!

I love how there were so many counterweights, why not make it RC and with the gearbox anyways? 

[Carsten Svendsen]

You're right that it is an impressive creation. I think you could make this work, you'd just have to fix whatever you mentioned was wrong.

To prevent the main frame from bending I'd recommend going full on brick mode and stack a few on top of each other for maximum sturdiness.

The rollers does look quite wobbly, maybe you could make some magic happen with the new quarter gear racks from 42055?

You seem to have heaps of space for the gearbox design. You could build anything that would be much sturdier than that, surely.

 

I'd say, yeah it's a big fail if you wont try and improve it. You say it's just been sitting there for a year, maybe now is the time for a second chance?

[Saberwing40k]

5 hours ago, MattL600 said:

Very impressive and very ambitious!

I love how there were so many counterweights, why not make it RC and with the gearbox anyways? 

I have no idea why I did it that way in the first place, guess I didn't see much of a point in making a remote control model of a static crane.

1 hour ago, Carsten Svendsen said:

 

I'd say, yeah it's a big fail if you wont try and improve it. You say it's just been sitting there for a year, maybe now is the time for a second chance?

Sorry, but like I said, this thing is demolished. I need the parts, and I've got other projects that I'd rather restart over this. But I will revisit ring cranes, just not anytime soon.

[Wolf_Zipp]

Hello Saberwing007

You have named the most Fails yourself, that´s the way to get better!

My first question:

Is the crane standing only on the ring ? I see no groundplate where it is fixed. You need a turntable in the middle.

Without this Fixing you will get no stability for turning gear. And the crane may fall down.

The Gearbox and Winches maybe build with technicbricks , 5 or 6 on top of the other.

The structure may go strong to the turnpoint of the boom.

I have not build this typ of crane, but i see two witch where 3 times higher, and they work

The red is a crawlercrane, the yellow is a wheel-mobilcrane

IMG_20170616_225429 by Wolf Zipp, auf Flickr

Edited August 20, 2017 by Wolf_Zipp

[nerdsforprez]

On 8/19/2017 at 6:02 PM, Saberwing40k said:

Lastly, the hook was not heavy enough to put tension on the hook line, and so the lines of rope going to the hook would jump at the slightest provocation. Still, even if this did fail, it looked impressive, and I learned from it.

IMG_20170813_202442189 by Saberwing007, on Flickr

 

The first picture actually did not seem too bad.  In fact, you really can't tell that the bottom is bending that bad. 

But down below.... I see your problem.  As others have mentioned, there needs to be multiple layers of LA so avoid the bending.  Was the crane in this position for the whole year?  Or did you lower the boom to demonstrate the bending?  If it was like this for the last year I assume those elements are ruined? 

Lastly, using the multiple pulleys is a problem with Lego b/c they have axle holes through them.  In the future, either use another element, or drill holes through the axle holes.  I did that with the pulleys on my own cranes, and they now work like a really pulley system.  Efferman also sells the pulleys with a pinhole as well on Shapeways (but neither are purist methods so I save myself the money and just do the drilling).  I still need to always have weight, in addition to the hook  block, so they don't jump.  Re-reeving the string on the pulleys is such a pain!!!!!      But this is no different than in real cranes.  In real cranes, hook blocks in some of the heavy-duty cranes can weight over a ton themselves!

 

[Saberwing40k]

Just now, nerdsforprez said:

The first picture actually did not seem too bad.  In fact, you really can't tell that the bottom is bending that bad. 

But down below.... I see your problem.  As others have mentioned, there needs to be multiple layers of LA so avoid the bending.  Was the crane in this position for the whole year?  Or did you lower the boom to demonstrate the bending?  If it was like this for the last year I assume those elements are ruined? 

Lastly, using the multiple pulleys is a problem with Lego b/c they have axle holes through them.  In the future, either use another element, or drill holes through the axle holes.  I did that with the pulleys on my own cranes, and they now work like a really pulley system.  Efferman also sells the pulleys with a pinhole as well on Shapeways (but neither are purist methods so I save myself the money and just do the drilling).  I still need to always have weight, in addition to the hook  block, so they don't jump.  Re-reeving the string on the pulleys is such a pain!!!!!      But this is no different than in real cranes.  In real cranes, hook blocks in some of the heavy-duty cranes can weight over a ton themselves!

 

None of the parts are ruined. Even though they were bent, it was just part to part flexing. So, they're still good, a testament to Lego quality.

Also, I didn't use the pulleys with axle holes. I used primarily Wheel 11mm D. x 8mm with Center Groove, because of the exact issues you mentioned. And, as I mentioned in my main post, I couldn't add enough weight to the hook without the rest of the crane falling apart.

[nerdsforprez]

2 hours ago, Saberwing40k said:

None of the parts are ruined. Even though they were bent, it was just part to part flexing. So, they're still good, a testament to Lego quality.

Also, I didn't use the pulleys with axle holes. I used primarily Wheel 11mm D. x 8mm with Center Groove, because of the exact issues you mentioned. And, as I mentioned in my main post, I couldn't add enough weight to the hook without the rest of the crane falling apart.

Wow...it really could not hold much other than its weight....cuz you don't need much to keep the string on the pulleys, especially when using the parts you mentioned. The grooves are much deeper than the pulleys I talked about.