howitzer

I'm not sure, but has the discussion in this topic spurred a new wave of WIP-topics here? Before I wasn't sure if I should make a WIP-topic about my excavator or just present the finished piece whenever in the far future it might be finished, but the discussion here made me realize that a WIP-topic would present much better opportunities to learn, for myself as well as others. Simply typing out whatever problems there might be helps in itself towards solutions and even more so if someone else contributes their thoughts. So from now on whenever I have a bigger project, I think I'll be making a proper WIP-topic instead of just trying to finish the build before presenting it. Contests also require a WIP-topic, and isn't learning and exchange of ideas the exact reason this is a requirement?

Hmm, I'm not sure what you mean, any chance you could make a quick model of your suggestion? Would be great to see the solutions in yours and the other build! --- Last night I couldn't sleep so I got up to do a major redesign: I turned the gearbox 90° relative to the boom, which appears to enable much more balanced and compact build. This requires some changes to the motor configurations, but I believe it's still much better than the original. Here's a couple of photos: The white collections of beams act as placeholder for the motors as there's no models for either Spike or C+ motors and the same goes for the dark azure battery box acting as RI hub. The pneumatic switch is similarly a placeholder and also built wrong here, but please ignore that :D Few things of note: - I got rid of the worm gear driving the boom functions and decided to use spur gears instead in several downgearing stages. This way friction losses should be smaller and there are no perpendicular axles so bracing should be easier. - There was a lot of juggling involved in positioning the slewing gears and gearbox controller motor and I'm not entirely satisfied with them yet. - I put a banana gear ring here to gauge the size of the machine and to see if it will be needed for greater support than what the large turntable can provide. A lot probably depends on how the boom and the motors balance out, though the larger slewing ring might be useful in any case as the superstructure is going to be pretty heavy. - I'm yet to design any bracing and that will probably be pretty hard to do, especially in a manner that is actually buildable. The cable and hose routing must also be figured out, though it shouldn't be too hard.

Some commentary on colours: Colours as a general is a very complex topic and the perception of colour is affected by huge number of variables. Lighting conditions, camera, image processing and compression, display all play a role. And it's not limited to technology, every person has slightly different colour perception due to the small differences in how the different types of cone cells in their eyes work. And it's not even limited to physiology, psychological and cultural factors also play a significant part. Apparently what we here in Finland think as "white" is actually perceived as blue in Japan, and their "white" seems yellow to us, there's even an anecdote of how this difference once caused a major disagreement over an order of a batch of supposedly white paper. So while the colour of the Colosseum doesn't exactly match the real thing, it's very much a matter of opinion if the choice is correct or not. Major part of how the Colosseum looks nowdays comes from the damaged and eroded walls and arcades, something that's next to impossible to replicate in Lego and there also seems to be a lot of colour variation in different parts of the thing. One could of course criticize the Lego model on not replicating those variations better, but YMMV. I also have to wonder, if you took the Lego model and put it next to the real thing, how would it compare? I hope we'll be seeing this some day. In the end the decision to use tan instead of white or bringing back very light bluish gray was probably made simply based on the fact that tan is a colour that most people think the Colosseum has, as demonstrated by @koalayummies - whether it's the reality or not. There's absolutely no other options than tan and white in the current colour palette and making a new colour or bringing back old one would've meant discontinuing some other colour, as today TLG has a policy of fixed number of different colours. I'm sure this is not feasible for a single set, especially when the parts required in a new colour would've been huge. As for other thoughts on the set, I was initially curious about it, and for me it seems to be a very well executed model but at the same time somehow disappointing, and it's hard to put a finger on why. I read the New Elementary's review and it hilighted some minor issues but mostly they are such that I don't really mind. The wrong ratio of column width to opening in the arcades is a significant flaw though, but there's probably no way around it at this scale. I also feel it might have worked better with a square base, though I understand the choice of oval base as that provides more interesting build and reduces footprint. At first the price seemed to be surprisingly low, but that's explained by the multitude of small elements with relatively low amount of lots and lack of license/minifigures. It would probably be a great parts pack for castle builders (something I'm interested in) but I don't think I'm able to spend this much of money on it, especially when I'm not that interested in keeping sets built on display, beside a select few. The repetitiveness of the build is to be expected, as there's simply no way to make such a model without it being repetitive. Someone with too much money should probably buy two sets and do a "restoration" to build the model like it was in its glory days.

Thanks for your thoughts! I considered using the four (or three) possible positions of the wave selector but using four motors (plus boom extension which is separate from the gearbox) will allow using the whole boom without needing to switch gears. Of course it would be possible to program the gear selector motor to switch gears whenever another function is needed but that would introduce significant delay so I think I'll stick to the two-position gearbox with 4 sets of functions. Hopefully I will be able to build the gearbox in a way that it's properly braced. My earlier PF-driven build indicated that it's possible to drive the boom functions with bevel gears, but I have thought about using linear actuators for luffing the boom instead of driving the turntables directly. I experimented with it earlier but finding the correct geometry proved to be a challenge so I stuck with driving the turntable. Maybe I should give LA's a second try though. Additional thought with the above: reducing number of motors with gearbox design would allow the connection of RI sensors like colour sensor, which could be combined with colour-coded turntable base so that it would detect the amount of rotation and stop where commanded. I'm not sure what use that would be though, because similar functionality can be done simply with motor position sensing...

More pinned topics is a bad idea, because it puts more and more interesting topics to the second page, depriving them the attention they deserve. If more pinned topics have to be added, I'd rather see a subforum created for them. Rather than splitting the users to pro/not pro categories, I'd like to encourage more comments and exchange of thoughts. WIP-topics are great in this regard, and it would be nice to see also the highly skilled members of the forum posting WIP-topics, as that would present opportunities for others to learn about their design and building process. As for the instructions sellers, it's nice to see especially well-designed B/C-models and their instructions being posted here but even with those there should be more "meat" in the post than just photos and a link to the seller's website as this forum shouldn't be just a platform for advertisement. Exchange of thoughts, ideas and feedback is after all the main purpose of this forum and also its main advantage over Youtube and other platforms.

If I understand this right, it means that the chassis is articulated just behind the cabin, am I correct?

This is very true. I consider myself pretty skilled in English (I was even praised by the teacher of Academic English course recently) but still I do and I always will miss some of the subtler meanings, as those will only come to those who grow up with the language. It's no excuse to be rude though, basic politeness is something that everyone is capable of learning. I personally don't like the over-flowery sugarcoating of criticism but there are times when a little bit of softening in the language used would be nice. Still, I'd rather have the "this will never work"-type comment stabbed right into my pride than encouragement to build something that cannot be made to work. About flying Lego things, I'm sure a fixed-wing aircraft is patently impossible but there was actually a Youtube video of Lego-built drone. Granted, it used third-party power source and control electronics, but still, the propellers, motors and chassis were all Lego, which is I think is pretty cool.

I also love the creative use of the mudguard! All in all this B-model seems so... polished. Definitely a top-notch B-model. This and some other great Land Rover B-models make me sad on how the official B-models have been disappearing from recent sets. These unofficial ones show the huge potential in making multiple builds on very limited parts palette and it feels like a wasted opportunity from TLG to not show the true potential of Lego anymore in B-models.

I thought of that, but it wouldn't help in any way to make the pivot mechanism smaller so not much point as the boom telescoping works fine as it is.

While excavators are long-time favorite of Technic, I recently saw something new in a construction site nearby: an excavator which had a boom that telescoped and rotated around its axis, instead of articulated jib. I then learned that a company called Gradall makes those, here's an example: So I set out to build one, though I make no attempt to replicate the looks exactly as some parts of this machine are next to impossible to replicate in Lego, at least in reasonable size. The first problem was the triangular cross-section of the boom, but very soon it became clear that it's not feasible so I settled for squared cross-section. Considering the functions of axial rotation, luffing and telescoping it also became clear that the motor driving the telescoping action would have to be located on the boom, and hoses for the pneumatically operated bucket would have to run the length of the boom and exit at the back so that there would be room for extension. I wanted to extend it as much as possible, and some 11-12 studs seems to be reasonable maximum. Here's a photo of one stage: Next in line was an attempt to build a superstructure which would support the batteries, pneumatic controls and gearbox for the axial rotation and luffing. At this stage I didn't even think of full motorization or remote control, I don't have PF parts for that and it was already complex enough. I got it as far as testing the motorized boom functions which more or less of worked, but I wasn't satisfied with the performance and there was a lot of problems with the gearing anyway. Here's a photo: At this point I was at sort of a crossroads: take apart and rebuild the superstructure to fix the aforementioned problems with gearing and try to finishing the thing OR make it even more ambitious with the Mindstorms Robot Inventor set that I just recently bought. It would have 4 additional motors (to complement the two PU medium motors I already owned) and hub with 6 outputs which could be controlled much better than what PF allows, enabling perhaps full RC control with proper programming. I chose the latter so that's what I've been doing recently. And it hasn't been easy. First I needed to decide how to use my motors and how to connect them to the functions. With motorized drive (2x tracks) and slewing in addition to the boom controls (axial rotation, telescoping, luffing, bucket switch and pump) there are more functions than the hub has outputs so some sort of gearbox would be required. The 8043 Motorized Excavator acted as an inspiration with its 6 functions for 4 motors, and I decided to try similar gearbox solution where 4 two-position selectors are moved with one motor at the same time so that in one position you can drive and slew and in another position all boom functions can be operated. I also stole the coaxial drive mechanism for tracks from the same set. Here's where I'm now in photo: And in digital model: I recently realized that it's almost impossible to use the angular motors in driving the boom extension, so I ordered a C+ L motor for that purpose and I'm waiting for that now. I also ordered a new type of pneumatic switch, so that it's easier to operate with motor. Some problems at this stage: Is there any way to make the boom support narrower? The problem is the gearing for axial rotation, which seems to be pretty much impossible to fit in between the turntables in any narrower configuration than this: Another problem is the gearbox construction, how to route all the functions to their places while still having the gearbox to be properly supported and smooth so everything works fine. Especially the axial rotation seems to be hard to achieve as there is a lot of resistance in the thing. With the earlier PF iteration I tried routing the gearing to both sides so that both turntables would rotate and while it sort-of works it of course introduces a lot of gears and friction. Turning just one turntable would have the force directed through the boom to the other turntable and that requires a lot of force too so it's probably not feasible. And of course I haven't even touched the programming side of things with the RI hub yet, but I suspect that'll be much easier. Any thoughts or tips?

The high quality of the many MOCs posted is somewhat off-putting to someone lowly skilled such as myself. I try not to allow it to prevent myself from posting but still it makes one carefully think how to present the MOC. Of course us who are less skilled should post also more so that the forum doesn't create an impression that cool, well-built MOCs are easy thing to do and those who can't seem to accomplish that on the first try are just bad builders.

I feel that the more specific the question is, the more likely it is to see EB topic high in search results. If you only want to see Ferrari MOCs, then EB isn't great place for you anyway, because other sites like Rebrickable offer much better search and categorization, plus easy to use unified interface, whereas EB posts are all different in the way they are presented and the search results are cluttered with all kinds of irrelevant topics. But that's sort of beside the point, EB is a platform for discussion and I'd much rather ask a question or post a MOC for feedback on platform like this than in Youtube or whatever. It's true of course that parts introduced with Chiron gave a huge boost to novel gearbox designs and much of the old designs became obsolete. Still, even if something becomes obsolete with new parts, the old stuff is still there for those with historical interest or maybe for those who don't have the newest parts and need to design around them. I also think that EB is one of the best places to find info on new developments as well as the older stuff, but that of course is entirely dependent on people presenting their builds in here and getting feedback on them. Topics dropping quickly to obscurity is a real problem yes. It would be nice to have the topics per page increased in order to keep more stuff on the first page.

Yep, when searching with that specific set of words, Eurobricks is only the twentieth result for me. But very often when I search for something more specific (like just earlier today the slipping torque of the clutch gear) I see Eurobricks as one of the top results and often with the best answer to whatever I was searching for. EB has been around a long time, and has a huge amount of information which is hard to find anywhere else. Of course much of that is buried in the long-forgotten topics but still a search often turns up answers to whatever you're wondering about Lego. There is a value in that, and while bulletin boards like EB are somewhat dated form of social media, I think we should all work to keep this place alive and active for years to come. This will come down to posting MOCs and keeping up with the commentary on them.

That wheel hub in tail rotor is really ingenious! And the view inside makes me feel like I'm looking at a real helicopter, not just a model. All those shafts and motors and stuff going to various places, while still having space for an actual cabin and cockpit.

All these comments about people not getting feedback or commentary on their creations is of course criticism for all of us. Why are we not engaging more with others? Even if it just a few words, any comment on a thread makes you feel like someone out there cares and this helps to keep you motivated, so why are we not doing that more?

I don't know about changes in trends, but at least concerning this forum, my feeling is that majority of MOCs are models of real-life machinery whether cars or construction equipment or whatever. Only significant exceptions seem to be GBC-related stuff, which still pops up now and then, anything else is quite rare. Maybe the times really are changing, as in the past Technic was all about function over form and the first licensed set was released less than ten years ago, but today multiple licensed sets are released every year and they seem to be outnumbering non-licensed ones. I'm personally a very slow builder and I often get ideas and then abandon them before completion so I don't have much worth of posting. I also don't use much other media such as Youtube so can't say what's happening there (although Brick Experiment Channel has had some pretty neat stuff). Whatever it is, more activity and more original designs would be awesome, but I'm not really in a position to complain, considering how little I get built myself.

Ok, thanks! I have a project which requires such a switch, and the motor I'm using is not actually PF M but Spike M instead, which should have similar torque. Looks like I'll have to build a test rig when I get my hands on the switch (waiting for a BL order to arrive..) to determine how much gearing is needed.

Just a quick question: can anyone tell me how much torque the pneumatic switch with axle hole ( https://www.bricklink.com/v2/catalog/catalogitem.page?P=bb0874 ) requires to be turned? Can it for example be operated with PF M motor without gearing for more torque?

I thought about this too. Of course the colour isn't exactly accurate and major part of how the Colosseum looks nowdays comes from the damaged and eroded walls and arcades, something that's next to impossible to replicate in Lego. The real colour also seems to vary a lot depending on which part you look at and how are the lighting conditions (which of course affects the model too) so I find the criticism on colour a bit odd. I also feel that, at least by looking at various photos of the real thing, tan is very much close enough to be the correct colour choice here. As for more general commentary, I was initially curious about it, and for me it seems to be a very well executed model but at the same time somehow disappointing, and it's hard to put a finger on why. I read the New Elementary's review and it hilighted some minor issues but they are such that I don't really mind. I feel it might have worked better with a square base, though I understand the choice of oval base as that provides more interesting build and reduces footprint. At first the price seemed to be surprisingly low, but that's explained by the multitude of small elements with relatively low amount of lots and lack of license/minifigures. It would probably still be a great parts pack for castle builders (something I'm interested in) but I don't think I'm able to spend this much of money on it, especially when I'm not that interested in keeping sets built on display, except select few. The repetitiveness of the build is to be expected, as there's simply no way to make such a model without it being repetitive. Someone with too much money should probably buy two sets and do a "restoration" to build the model like it was in its glory days.

42082 had pretty bad B-model. Exact same chassis (which included major part of the interesting construction aspects) combined with really lackluster superstructure. The idea of a pile driver is somewhat original, but the execution leaves a lot to be desired. With the parts palette of this huge set something much better (telehandler, anyone?) could've been done, as the multitude of unofficial C-models show.

As others said, it cannot have been fried if it wasn't connected to a power source. This thing happening overnight would imply a pest of some sort, but if it happened gradually over a longer time, it would suggest degradation of the insulation plastics.

I haven't had much time yet to play around, but it seems that it takes quite a bit of effort to build something more than very basic stuff so I don't expect results soon. Learning some Python was also a goal for myself, so I hope it will be useful for that. Thanks for the info. I should've been more precise in my previous post, I meant power control instead of speed control. My aim would be to be able to control the dumb motors with variable speed similar to the Batmobile, which of course does the controlling by power control. Another thing about the motors: both the Batmobile motors and RI motors emit a high-pitched whine when powered, which I find weird. Anyone else have experienced this? PF motors don't do it and neither do the old 9V motors.

I tested the dumb motors on the scratch environment, but couldn't find any obvious way to get them to move, at least not with the same commands as those used to move the angular motors. So I guess I'll have to use Python in this case, which I planned to do anyway. I find the limitation of not being able to control speed curious, as the Batmobile includes speed control, so how come it works with the official app but would not work with user-made code? Or maybe there's some way to control speed with Python but it's somehow not obvious? Speed control isn't critical for my first project though, so it's not a big deal.

Ok, so I got myself the Robot Innovator. Now I am somewhat confused about the parts and compatibility, specifically motors: Are the motors the same as those included in Spike Prime? If not, what are the differences? Another thing, I have the App-Controlled Batmobile (79112) and it has two motors which I assume are the same as Powered Up medium motors (part 21980), so should I be able to control those with my RI hub? I'm expecting only speed and direction control (not position control or feedback.)

Ooh, I will have to watch these, as I bought 51515 just today.