SaperPL

The weird part is that it sticks too much outside from the bottom outline. I'm not sure, but maybe you should angle the motor with some gearing so it is along the edge instead (if there's an actual engine on the inside? Also can you share some photos from different angles and maybe a reference photo of the exact machine you're basing your model off?

This is awesome. The only thing I could suggest is that maybe you could make the box on the right side with technic panels instead of system bricks to be further away from model team approach.

I forgot to add this truck here: Instructions: https://rebrickable.com/mocs/MOC-107909

artemisovsky built this already: More photos: https://rebrickable.com/mocs/MOC-107909/SaperPL/mini-euro-semi-tractor/#photos

Looks really good. One thing I'd suggest is to replace that axle connectors (32039) above the 90 degree pin axle connectors (10197) which you're planning to use for attaching the pistons, with a 90 degree pin axle connectors going inward (32014) and secured in the middle. The 32039 connector will most likely break easily there.

Front looks really cool with the cab and technic fig. I'm wondering about the back - isn't there any way to fit those two motors for the arms in somehow more compact way? Same thing is bugging me in my model that I'd want to have the rear lower than the cab as in real life loaders, but the drive for tilt is cumbersome.

I asked two times on the discussion topic and didn't have response from @Jim , but he stated those two things: Yup, I have removed limitations on electronics and pull-back etc. And since buwizz 3 is allowed (a small 6 motor supporting RC hub that handles both PF and PU, I believe CADA micro motors to be fair game unless Jim says otherwise. Didn't knew that they are slower, but well. Yes, I know about this. I'll be working on it as I need an attachment point at the middle of each linear actuator for them to not wobble so much. But I might need to start from scratch and re-scale/upscale it a bit as there are multiple shortcomings of going this small. It'll all depend on what I'm going to do with the arms.

I asked Jim that twice and didn't respond and others assumed that if general RC restrictions are lifted, those should be allowed. Also Lego had micro motors that are 1 stud shorter, so it shouldn't be that big of a problem. From my perspective, it's similar problem of buwizz 3.0 which has 6 motor outputs in compact package making it pretty competitive.

Well, my point is that it'll be hard for me to make it look really well to compete against other great entries we already see emerging, without going for model team approach on some big portions of such small model. I know the model here is not up to the competition so far, it's just a prototype. I'm just thinking about whether I should upscale for the sake of looks, or whether I should go with a different topic/machine altogether and maybe even manual model.

Thanks! For one, at this scale attaching the linear actuators up there in the front would mean routing the input and making a lot of mess of the arms. I feel like this approach is slightly cleaner at small scale. Secondly for a machine that can work as a forklift, I believe it should have this kind of feature - it is probably an option in the computer to control the tilt like that when raising the arms, or there should be a way for the operator to precisely control the speeds of rising the arms and bucket tilt change at the same time for the angles to even out. Anyway: I'm still not 100% sure if I should go with a model like this for the contest because it may be hard to beautify it without going full model team on the arms and the cab. There is still a lot of time and I can see a lot of potential in some manual models being made while pushing for RC functionality is a double edged sword when it comes to small scale models.

It doesn't tip over, the battery box/hub is right in the middle and that's the most weight in the model. The back should stick out as there is potentially a weight in the bucket. I think the issue with how it looks is that those curved panels on the sides of the rear are visually increasing the size of the whole back where the real life machine doesn't have it that wide. Anyway, I've tinkered around with arm geometry and it's a bit cumbersome, so I'm not sure if it's final or not, but I have something to show: The bucket is being held at same travel as long as that white 24 tooth gear is locked in place. I still need to figure out the mounting of the motor for that gear, but it shows what kind of range of movement I'm thinking about. I probably need to reinforce the linear actuator attachment points at the bottom as it wobbles a lot while extending. The gif is at 2x speed - I'm planning to replace the input gearing inside the actuators from 12/12 to 24/12 so it'll be slightly slower than what it's on the video. Driving works and has pretty cool wobble/jitter :P

Well, if @Jim didn't respond and since there are indeed smaller micro motors by Lego, discontinued however, but still, I'll take it as a yes unless he says otherwise. Well, that's one of the reason I'm not "putting too much effort" as you said, meaning I'm doing it mostly for fun and I also don't want to overspend hoping to win. Big projects can pretty easily fail :P

Thanks! I just checked this interesting geometry and it is really cool, but the issue is that it tilts the linear actuator a lot to shift the arms forward and the actuator would get blocked on the tracks. Probably better to keep things simple especially that I don't have any idea on how to tackle the drive connection to the tilt lever with such complex geometry...

Yeah, that's my point, I'm not sure whether I should be paranoid here and avoid using system elements in bigger visual accents, and whether I can get away with making a big portion of the cab with system bricks because there's a system/brick shaped hub on the inside. Let's see what @Jim says about it. If that's okay as long as we're not going full system on the outside, then maybe I should make a system based cab to have half stud gap between it and the arms of my loader

So I've been contemplating what to build for the contest as the volume restrictions is something that should fall exactly in my area of expertise, but with RC allowed, it got a bit complex. To fully handle a crane or excavator you need 5 or 6 motors, so either two hubs or something like buwizz 3.0 which supports 6 motors, and I'm not really sure if I'll be able to fit all that perfectly within the specified volume while not making it a messy build. So I decided to stick to stuff that I can power with a single hub, and I love the ease of use of physical remote from CADA so I ended up deciding to go with a tracked vehicle + two mechanical functions, so after looking at multiple options I decided to pick a tracked skid-steer loader - a bobcat: I like this one because it has an interesting geometry of the arms, which I expect to be there in order to prevent the bucket getting closer to the cab while the arms are getting raised. I yet have to test this theory. Here's a concept / design so far: I tested the geometry of the arm against keeping the bucket at same angle while the arm is changing its angle, assuming the lever holding liftarm over the arm has fixed angle, and it works more or less. I don't have a bucket yet, and I've got to figure out the driving connection for it that has a significant gear reduction as well as it should have some safety like clutch gear, but I'm not sure if it is a good idea considering weight of the bucket. I'm not 100% sure that I'll be able to go with the design of the arm that is supported by that liftarm to move forward/keep horizontal position of the bucket, especially because of the requirements for the bucket tilt lever connection to the motor. Additional note here is that the tracks are shaped in a way that rear gears one exactly above each other because I couldn't achieve optimal track tension in other configurations and also I would have to make more space for the attachment of linear actuators behind the tracks and it would complicate the base structure. Finally I might end up with arms hitting the cab, so maybe I'll have to move them by 1 stud to the sides, which would made the proportions weird, but I don't think I'll be able to shrink the cab without showing a mess of cables.

Really cool model, I love the small accents here and there.

The cab is awesome, but how about the no-model team approach? Aren't the rounded areas in front of the cab, edges of the roof and grey edges over rear wheels exactly what you would call a model team approach? I'm asking because I'm wondering where is the boundary when it comes to model team approach and I'll have to use some system bricks in few places because I'll have micro motors and studded hub. Or does the model team approach is supposed to be treated as a whole model/outside of it with system bricks and not only just parts of it?

Ok, this is actually brilliant on how it depicts the roundness of the cab, that slight angle there to match the round panels on the side and to angle the dashboard and steering wheel at the same time - awesome attention to detail here :)

Really good start. I like how the supports are made without nedlessly wasting space to make supports that go sideways. This approach is good too. Right now the wheel distance feels a bit off without picturing this specific excavator, but looking at the pictures I guess you've measured that correctly and it will be as in the real life vehicle when you'll put the cab on top.

May be a stupid question, but if you're going for dark variant with LBG grill, shouldn't you try using all LBG frictionless pins to not have black dots on it? Or all those are 3L long pin axles or just 3L pins in black? :D

I think you need all wheels to be driven as otherwise the non-driven wheels will add resistance against steering.

Video and Instructions are live: Instructions on Rebrickable: https://rebrickable.com/mocs/MOC-107909

I'll drop this one for the inspiration as well: The interesting things here to note are the headlights, the different sized wheels with same tread and the steering wheel connection to HOG steering with 12t gears connected at angle. I remember that adding those headlights at the front changed the look drastically and having a steering wheel working allowed for a cool shot in the video with GoPro attached to the back of the tractor from the driver's position.

@Jim Are CADA micro motors OK? Lego had even smaller ones.

Maybe you could go with same size wheels? JCB does something like this (I've seen one like this IRL recently):