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Is the track suppose to be that loose on build 8288
Just started my 8288 crane build and enjoying it so far. I did notice with 43 track pieces on each side it makes it ride very loose and gives it a droopy look. If i remove one link its too tight and doesnt really roll. Has anyone here built this with similar issues? Thanks
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First off, the alternate is huge (about 3ft high). The crane actually wobbles now, which really can't be helped due to the nature that Lego really wasn't designed to make that large of a structure at scale. So I'm not going to subtract that.
They use a triple-pulley (as opposed to the double-pulleys they used for everything in the main model) for the joint inbetween the long beam and the short beam, which is cool. I think they did that because a double-pulley would have caused too much torque on the click-mechanism, but regardless, I like it even more than a double-pulley.
Now, I thought the counterweight was weak before, and now that this extends even further out, I feel that the counterweight is even less useful, which is the huge problem. You can somewhat allieviate this situation by turning the crane so that it's perpendicular to the treads. Since the treads are wider (21studs) than they are long (15studs), you get an extra 3-stud's of leeway with the center of gravity (COG). For those of you who need to brush up on your physics, if the COG extends past the base, then the structure will topple over. If you increase the base, then, you get a more stable structure (ala outriggers).
However, that didn't quite solve the problem altogether. So I got my bix-box-o-lego out and dug out my two boat weights that I already owned prior to this (I now have 4, woo), and extended the counterweight structure backwards by two studs. This was actually pretty easy to do (add 4 2x6 plates, a bushing, a 1/2 bushing, remove the pole reverser handle and replace it with a perpendicular axle joiner + 4stud axle). Not only did this double the weight of the counterweight, but it also made it slightly more effective, since it was now extended two studs further back. Again with the physics, the farther away something is from the COG, the more torque it applies on the structure. In the counterweights case, the newer rear weights "weigh more" than the older ones which are closer to the COG. It even looks better this way too, in my opinion.
So now this is noticably more effective than the old counterweights. I can extend the crane almost completely down (I can get about 60 clicks away from the fully extended position before it topples over) now. So this set really does need 4 boatweights, and not just 2. 6 would be perfect for the alternate, and I'm pretty sure 4 is perfect for the main model.
The looseness of the treads began to annoy me, so I tried removing one link from each tread. This was a little difficult to attach, and in retrospect was a bad idea, because I ended up warping the connects of one of my links. So don't do this.
Also, when building the main model, it says to cut the longest string so that it's 80cm (I think?), which is a good length for the main model, but if you plan on building the alternate model, I would suggest you cut it longer, since the alternate doesn't allow enough length for the main string to lower the hook below the bottom of the treads (which you might want to do if you have the crane working in a quarry-type environment where you lift things which are down a cliff from you). There's a ton of string, so don't worry about not having enough.
I think that's about it? I want to build it even bigger now, but unfortunately I don't have a lot of white technic beams (actually just 4 more 15stud beams), so I may buy another if I find it on sale somewhere (more treadlinks and boat weights, can't really go wrong)