mdemerchant

Nice job. It should be more accessible in this size for more people to build. You even have a tiny operators cab. You are missing the box for the chain to pile into though. Do they use that on all the sizes of SK cranes or only the biggest ones?

I'm fine with a big model costing more than that. But I think it probably strongly depends what kind of MOCs you buy and why. In my case, the ones I buy are almost always fairly large/complex things I want for display pieces in which case I'm going to order typically hundreds of dollars of parts for them anyway so the instruction cost is not that significant. But if you are looking to buy MOCs just for something to build with your parts you have then I can see you will be more concerned about the price. I rarely do that because if I just want to build something I'll just build something myself most of the time.

Wow, all of the examples all of you gave are very reasonably priced and so few takers. @M_longer, your Volvo is a great model and it got plenty of views, around 4500. I'm shocked it has so few purchases. I have only a couple of free MOCs posted and they both have thousands of downloads, one has nearly 14000. Around half the people that view them download them, versus less than 0.5% for the Volvo. I was quite sure that having a price versus free will obviously greatly reduce the number of people who get the model but I never would have imagined it could be by 100x and for one of the most popular MOCers on Rebrickable. I wonder what happens if you just charge some nominal amount like 1 euro. Maybe there's a magic price point that can drive volume, even though it seems unreasonably low given the quality/complexity of the MOC.

This is an interesting point. What is the actual mechanism by which you get paid through Rebrickable? I have only posted a couple of MOCs for free so I never really thought about it. But I always assumed money would get directed to you minus some sorts of fees from RB and whoever else may be involved in handling the payment so you collect less per sale than the listed sale price. But your comment kind of implies you have some fixed overhead cost just from being setup to sell MOCs. If you run you own website I get it but does RB work that way?

Your question kind of got lost in the other discussions but here is my two cents. The gearing is probably the major problem with responsiveness, not the U-joints. Consider that 270 degree rotation of the worm gear will only turn the 16T gear 3/4 of a tooth. This magnifies all the slack in the system and is going to make the steering super slow even with no slack at all. You will be much better off to find a more direct routing of the steering and use closer to 1:1 gearing assuming this is a non-RC model. If you really can't avoid sending the steering sideways it would be better to use a chain or even a bunch of 16T gears in a row rather than sticking in a worm gear to turn the transmission axis and U-joints to turn it back. If you really, really have the turn the axis then use some bevel gears instead of the worm gear.

This looks great, really well done. I like that it has a few functions that are beyond the standard 4 function loader. My current project also happens to be a loader but I can safely say it's unlikely to look nearly as impressive as this one.

Yes, it is too wide for scale by quite a bit. Those tires look good but from the video they seem really soft. Do you think they will be able to support heavy models like this or your Grove? I guess the weight is distributed over a lot of tires, maybe ok. I did not make a video originally and my crane has been disassembled for a few years so I can't make one easily now. @seregiz and @nigel1975 both took some awesome photos of theirs but told me it was too large for them to easily make videos.

They are certainly going to make the build much quicker which is good if you are the sort that really gets bothered by repetitive building. I think the resulting structure is probably also a fair bit stronger than most built up 7x7 lattice booms, mainly because they have cross bracing in both directions where most people build those booms with two flat lattices just connected by axles so they are flimsy in one axis. I don't have the parts though so can't say for sure but in looking at how they are assembled they must be stronger. I think the main limitation is they only work well for a 7x7 cross section. If that's what you need for your crane, great, but if you are interested in making something closer to scale most cranes don't have booms with square cross sections and don't use a fixed cross section for boom, jib and derrick. So I don't think the parts are as flexible in their application as they ideally would have been.

Great choice but that's the one PU set I own so I don't need a conversion Although I did convert it to C+ full RC after I was done playing with my 42100. Unfortunately I don't have a complete design file for it or I would post it. Doing the conversion of the original set should be pretty straightforward, only one motor to deal with and it's got space. Now I feel like building Big Red again... such a good set.

No, actually I find it easier to thread through things because it's thinner but stiffer. It's not really that prone to tangling, just more so than the Lego string which is nearly impossible to tangle. If you throw several meters of the Kevlar in a heap on the floor and then wind it up you are likely to come across a small tangle while winding but it isn't prone to tying itself in real knots.

It's also just using the tilt reading from the hub but the linkage makes the hub tilt more than the rest of the superstructure does. The control may be slightly more complicated/less good with the load sensor because you can't just control it to have zero tilt. You probably need to have just open loop control based on the sensor reading and some math. But if you just put the hub in the superstructure and use tilt I'd be worried about it having very little precision and the counterweight position constantly hunting all over the place. I guess you can put some coding in the control loop to minimize that.

In theory this would be easy to do using just the tilt of the superstructure but I'm not sure the hubs have enough angle precision to make it work well. You could also do it with something like the load sensor mechanism the model already has which may work better. I don't think the V frame is actually available for the LR13000 if you're going for realism but it will look cool and be fun to build so go for it and show us photos I was actually thinking of building an LR11000 as a future project mainly to do the V frame.

Personally I use 100 pound or 200 pound braided kevlar usually for my cranes, get it from Amazon. https://www.amazon.ca/gp/product/B089SGWBT5/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1&psc=1 It's strong and not stretchy and much thinner than Lego string so I can pack much longer lengths onto a given size winch. But it's not as soft as Lego string and can get more tangled. Not sure what kind Seregiz used when he built it. I know lots of people sell braided nylon on Amazon, any of those should be very similar to Lego string if you prefer that. All are cheap, even kevlar. You probably need about 20-25m for this crane. Well people here have already seen it so I don't expect a ton of comments, just wanted to make people aware of @seregiz's awesome instructions. It's getting plenty of attention on Rebrickable, a lot of downloads in just a few days. I'm surprised so many people would consider building such a big MOC.

Sorry to bump this but I'm pleased to report that @seregiz has made instructions for this and a cleaned up Stud.io file. Plus he took a ton of great photos. Now available on Rebrickable and Bricksafe, free of charge. I contributed a Stud.io file for the luffing jib and 3rd winch for anyone adventurous but I didn't do instructions for them, they are simple enough to build. https://rebrickable.com/mocs/MOC-169020/mdemerchant/liebherr-ltm-11200-mobile-crane/ https://bricksafe.com/pages/mdemerchant/ltm11200

When I saw Mobile penguin washing station I had to click it and I was rewarded. This is awesome, very nice build besides being an entertaining concept.

While Cada plays fair in paying the people designing the MOCs as opposed to stealing them and have gotten a lot of licenses I wouldn't say they are entirely playing by the same rules as Lego. Looking through their catalog there are still a ton of (spectacular!) models which are obviously certain real products that they haven't licenced. I'm not defending Lego but you can be sure there's no way Ferrari would ever allow them to release a non branded model of a Ferrari without their cut of the sales. I would also speculate that Cada doesn't compensate their MOC designers as the same level as Lego does but I hope I'm wrong since you're all doing a fantastic job. But in terms of just comparing the lineup of who has the nicer technic sets, Cada clearly has hands down better models. They have lots of the best MOC designers working for them and seem to let them make the models they want mostly so maybe that's just to be expected. The resulting sets obviously have huge appeal to people like us but I think it remains to be seen if they have the same mass market appeal as stuff from Lego. Interesting times for sure, lot's of things in that catalog that I would like to have.

The boom size is definitely looking better but the derrick is still way too short compared to the real thing. A significant improvement overall though. As others have also mentioned, I would get the main boom strap attached to the top instead of the middle to stop the bending. Also, personally I think the looks of the set could be improved significantly by replacing the two jib struts with new ones you build yourself. The real ones are longer and much more slender and I think the way Lego did it using the back to back A frames is a big part of what makes the original set look kind of cartoonish. Also adjusting the strap lengths to get the struts close to perpendicular to the boom and jib will make it look more realistic.

Well I do build things other than cranes but so far it happens that only cranes have turned out well enough to bother with posting. But yes I do like cranes, they are interesting machines that seem simple but actually have a lot of functions. Thanks to everyone for all the kind words.

Hi everyone, I have a simple model to share based loosely on the Manitowic MLC300 crawler crane. The model is fully manual and is about 1m tall in the most basic configuration you see below. I started building this is January because we had visited my family over Christmas and my nephew who is really big into Lego wanted me to help him build a crane. It wasn't practical to build much of a crane during the few hours we were at his house and he was mostly playing my kids anyway but later on when I was thinking of things to build I thought I should do a simple crane that would be easy for him to build and fun to play with. So I started building some crawlers with the intent of just making a generic crane but then I thought variable position counterweight makes it easier to play with and it might as well look like something so I decided to loosely model it on the MLC300. Liebherr cranes seem to get many more models, both Lego and diecast, so this is an under-represented subject. I did keep the design really simple, fully manual with cranks and knobs prominently sticking out and no trim like walkways, ladders and railings. I think you could put them on using system parts and really improve the looks but they would be super flimsy. Designed for an 8 year old, it's basic. The real crane, shown below, is I guess what you might call a small large crane. It's 300-400 ton capacity depending on the configuration so it's at the low end of heavy lift but it's much higher capacity than the 100 ton type crane that you might commonly see around on job sites. It also looks physically small for it's weight class, at least to me, I guess because of the shape of the crawlers and body. I happened to see a real one working on I95 in Miami in March and when you see it around those 100 ton type cranes it doesn't look so small in reality but I think it is smaller than the equivalent Liebherr for example. The special feature of the real crane is the VPC system which is a motorized ballast carrier than runs along a gear rack along the underside of the superstructure. This allows the weight to be moved to different radius to balance the load on the crane. I think this is part of what allows it to be a bit smaller, they don't need such a beefy slewing bearing because it can stay better balanced. The system can also be extended with what they call VPC max where they attach a big extension frame in place of the ballast carrier and the whole frame can move in and out with the ballast then moving along the frame as well. My implementation of VPC is super simple as you can see below, I just have the ballast tray slide on 15L beams on the superstructure. Putting in a gear rack would have been nice but I just couldn't see any way to do it without needing more clearance between the bottom of the superstructure and the tracks and I didn't want to lift the structure any higher or make the whole thing a bigger scale. In general the whole crane isn't very "technic" but it does have gearing on all the winches to make them faster and ratcheting locks. The model has the basic crane features: Two crawlers, no tensioners in them Slewing superstructure Tilting cab, can also be rotated around the front they way it would be for transport Winch to adjust the A frame and main boom angle Winch for the main hook Winch for an auxiliary hook Simple gravity ratchet mechanisms on all the winches Optional boom tip extension for the auxiliary hook Extra winch - used with the jib (there's a jib? we'll get to that) Moveable counterweight - I built them hollow and put a few old batteries inside. I stuck a pneumatic cylinder on the A frame which is used on the real crane during self assembly to pick thing up without having to bother with another winch. Not super useful here, it's decorative and not even connected to a pump. All modular so you can quickly break it down into the same types of pieces as you would the real crane for transport. You can also extend or shorten the boom by using more or fewer insert modules. Of course, once you start building a crane then you think, this is nice but it could be taller. It could be a more complicated configuration. It could lift heavier things. This of course led to building a bunch of accessories to have the VPC Max functionality and the full crane configuration with luffing jib. This is pushing the envelope for an 8 year old but if he has enough parts to build it it's light enough that it won't seriously injure him when it inevitably falls over. The accessories I guess add a couple more functions, the VPC moveable counterweight frame and an extra winch in the derrick to adjust the main boom angle. Overall I'm pretty happy with how this turned out. It's pretty simple but it's fun to play with and actually I have it sitting on a table with a smallish boom configuration and it looks ok as a display piece. There is certainly room for improvement depending on what your goal would be. Could be much more detailed for a display model. The one area I'm not that satisfied with is way the main winch is built into the boom. It's flimsier than is ideal and easily redesigned but I haven't gotten to it. Since the whole point of making this was to have something my nephew could build, I have made instructions for it. This was my first attempt at making instructions for anything which took much longer than I expected and led to lots of cursing at Stud.io "features". I have not built it from the instructions to test them but looking through them carefully I believe they are all correct and should be clear enough. The build is very simple, if there are minor issues I'm sure anyone reading this forum will have no trouble solving them. If anyone wants to try I will appreciate any feedback on issues you find. Instructions for the basic crane can be found on Rebrickable here https://rebrickable.com/mocs/MOC-164685/mdemerchant/mlc300-crawler-crane/ The extra bits for the bigger configurations are here https://rebrickable.com/mocs/MOC-165101/mdemerchant/mlc300-vpc-max-jib-expansion/ There are some extra renders and pictures in the Bricksafe folders https://bricksafe.com/pages/mdemerchant/mlc300 and https://bricksafe.com/pages/mdemerchant/mlc300-expansion I haven't put the .io files into Bricksafe but I can if anyone is interested in having them.

They probably have enough torque but I think you are going to want gearing anyway to make it move at some kind of sensible speed (ie. slow). If you try and make it slow by using direct drive and running the motors at slow speed it's unlikely to move. I don't have the set but from photos it seems like there would be tons of space if you are going to double the track widths. You should be able to fit in gearing. If you are going to double up the tracks I would go for covering them with tiles or just leave them uncovered. Lot's of examples in the past of people doing both and they both look good. Liftarms (beams) are not going to look very good, or at least they aren't going to look very crane crawler like.

It may not be practical to build an octagonal structure that small. The easiest way would be use round 1x1 tiles as rollers in the groove, if they fit. They work well in the bigger gear rack, not sure about this one, it might be too small. Second easiest way would be just use a 4 roller structure instead of 8.

Still no instructions but the LDraw model is posted on my Bricksafe page, link is further back in the thread if you want it. Now that I have some modest experience with making instructions for things I can say that it would take me a lot longer to build good instructions for this than I have time to put towards it. Anyone else is welcome to though. The model should import into Stud.io easily enough but probably needs some cleaning up of invalid color parts. I also realized I was previously building everything with an old version of black pin that is rare now, I'm sure this file will be like that. I don't know if @nigel1975 already has an improved .io file.

Does Cada outsource their production to a factory (or factories) that makes generic parts for other companies as well? Surely they haven't deliberately designed two different thread worm gears of the same colors in their parts lineup so seems like this would have to be a mix up at a supplier who is producing both types for different companies.

Looks great in those colors. Glad you enjoyed it so far. I'll be very keen to see how it looks when you finish it. I've actually been thinking about rebuilding it lately but haven't gotten around to it, been busy with work and a few other models. Anyway, now I would definitely have to order red and black parts to build it since my original patchwork version doesn't compare well to yours I will warn you to be careful with the flying jib. I didn't put any safety struts into the design and I managed to flip mine over backwards on a couple of occasions by raising it to too high an angle. The collapse was sudden and spectacular and not something I ever experienced with a crawler crane.

I think the idea is good because words matter to most people but I don't think it will entirely solve the problem. A challenge with judging, winners and prizes is still a competition by definition. But it could definitely help. As someone who unfortunately doesn't have time to be able to enter competitions and isn't a big contributor to the forum, I'm not sure this carries much weight but I do have a suggestion as well. The main debate seemed to be around the need for sufficiently detailed rules but to me there are two sets of rules. There are rules that define the constraints and determine eligibility. I agree they should be as clear as possible but Jim always seems very good to give quick feedback on any eligibility questions so that seems OK to me. My suggestion is about the second set of rules around how entries will be scored. I think we should just get rid of those entirely. Jury or public votes for the models they like. This is certainly what happens in the public voting anyway. You have a model that catches people's attention, they will vote for it. Totally fair to everyone involved and no one goes into the challenge thinking I just need to follow this formula to win and hence aren't disappointed when they follow it and don't or they perceive the formula to change halfway through. Look at it this way, a great piece of art isn't considered great because of some judging formula, it's considered great because lots of people look at it and think that's great. Same with Lego models in my opinion. I'll don my armor now