1980SomethingSpaceGuy

Hi @gijutsu-san96! Sorry about the dead links; OneDrive has reset all shared links a couple years ago. Here's some updated ones:

My daughter is in the Friends target age range. She loves those minidolls. And she's not got into the cartoon episodes yet... Indeed the color palette is painfully big and flashy and the dolls lack versatility, but at least accessories are still compatible with minifigs. Altogether, I totally agree with you; once you get over the downsides, Friends is in fact quite an interesting theme.

Yup; cleaned my browser cache, your profile pictures still don't show. Must be server side and since it's been worked on (thanks, btw) I guess we'll have that solved soon.

Good job, looks awesome!

I'm very happy to get my first podium in a TC! This build has been quite a journey and I want to thank the admins for running these contests, all voters for their interest in our models and congrat all my fellow participants; the competition was tough! Long live the TCs, see you in the next one!

Now these are cute little tracks! Sorry you had to ditch the T-Rex, hope we'll see it one day. Kudos for switching to low gear and still deliver a build for this TC!

The Snow Horse - PF RC snowmobile Meant to use a PF servo, this ended relying on a quite creative solution to actuate the skis based on the differential speed of each of the double track propulsion system. Handling is one of a kind but works surprisingly well on low friction surfaces like ice, snow or just a plain hardwood floor. Features full independent suspension with 2-axis of freedom on the tracked sled, actuated handlebars, 2 PF L motors for propulsion and steering, PF receiver and battery box.

Thanks a lot! Your model is really nice and works well with the action figure. Alas, I only have Darth Vader in this collection and his armor happens to forbid the leg movement required to sit legs spread, so it doesn't work with my MOC. Shot some last photos today for the entry: I only have a piece of white background and my mobile phone as a photo studio; it's a pain to get enough light. Anyways, thanks for watching!

Really nice bodywork, well done!

Yep, I tried that too at first. It was bending where it shouldn't and not moving enough where I would have liked to. Moreover, I had no good solution for the torsion spring. I picked this pragmatic solution with acceptable cinematic and external looks so that I could move on. But as we said, this is most likely one of the reasons why we haven't seen an official TLG model of snowmobile yet.

I have this issue with Onedrive sometimes where images won't show correctly. Clearing browser data fixes the problem.

Here's a quick render of the geometry: The upper (red) frame is attached to the chassis. The sled (blue) is on the ground. The tensionner (green) only supports the track. This allows translation of the frame on the vertical axis, in which case the magenta spring barely works: red/dbg/blue/magenta form a parallelogram that squishes down. As this happens, the total perimeter of the structure gets longer, forcing the green spring down too and spreading the load with the yellow spring. Front/back pitching happens around the pink axle (right in front of the pair of pulleys), in which case the front spring (yellow) barely works. Forward pitch (blue moving clockwise around pink) is limited by the length of the magenta spring, which is slightly compressed at rest. Backward pitch tends to shorten both the perimeter and the tensionner and both contribute to reduce track tension. This is not ideal but works for the angles allowed by the structure. Altogether, this is far from an exact reproduction of the geometry of the actual suspension system referenced in my previous posts and does not address track tension flawlessly. But it allows the two degrees of liberty I needed (translation+pitch), work well enough for the requirement and look similar enough to the real thing.

Really nice track design. Looking forward to see this one progress!

Nice choice! It has tracks, interesting features and a good post-apo vibe!

Thanks a lot! I spent an awful lot of time on small details, sometimes wondering if it was really worth it. I'm glad some of that effort shows Thank you so much; means a lot to me Yes exactly. I made a quick render of the steering gearbox (viewed from below): Red is the left motor Blue is the right motor LBG is the steering Thank you very much for the kind comment! The suspension system I implemented is of course a simplified version of the actual thing. It should rely on a compact torsion spring which is unavailable to us, so instead, I'm using the back suspension spring to tension the tracks. The geometry and thus the ideal length of the tracks change with suspension action, so this back tension spring has an active part in the suspension stiffness. It wasn't easy to balance this while still looking like an actual snowmobile suspension setup but the result is fair enough for a Lego model I guess. Yes indeed; only simple, small models of snowmobiles so far from TLG. But having built one now, I may have a few hints as to why. We mentioned the track suspension system; implementing a realistic solution most likely would require new parts. The front suspension too is hard to build the way Ski-Doo work; Technic ball joints have sensible slack; I tried to work around this by putting each pair as far as I could vertically, but those are much lower on the real thing. Also, in order to carry motors, a battery box and receiver, the model has to be quite big but with very few features; I'm not sure how they would integrate this to their lineup. Anyway, this is the model I took inspiration from:

I tweaked the track suspension to soften it a bit, adjusted the tail, moved the battery box one stud to the back and a few more details not even worth mentioning. As I caught myself smoothing edges with system parts, I thought it was time to record a small video. Close up of the steering system:

Thanks a lot; these positive comments from all you Lego fans and experts mean a lot to me. The handlebars are merely cosmetic at this point: it's not even possible to steer the skis using them; the belt drive (black rubber bands) they're attached to has less friction than the clutch between the steering rack and the differential (it was even more true with the servo). So to me, they belong to the things I want to remove as sub assemblies when working on the insides. Moreover, they are a bit too flimsy to safely hold the weight of model when flipped upside down (which is handy to do when building). Why would you want to keep them in place?

They're nice little machines with decent features and being proud of one's work is essential. Kudos for that!

Too bad this didn't turn out as well as you wished. There's still enough time to start another build for this TC, tho..

Thanks a lot, Paul! I spent a lot of time improving on the first body design; when I had to rebuild the whole frame, I wasn't sure the second would be as good. Especially since I had to cram the steering gearbox between the tracks and the skis, which is bound to taking more space than just the servo. But I managed to use minimal additional space (only one stud for a 20t gear, the rest fitting in the length of the L motor) and arrange the gears lower than where the servo used to be. This freed some space on the top where I could fit the battery box, which in turn allowed to improve the seat. I love how issues sometimes turn into opportunities when building LEGO. Thanks a lot, guys! Along with almost everything we sometimes think we invent when fiddling with Technic, I'm sure this has been done before. I first thought of doing this when I got 42095 in 2019 (Remote-Controlled Stunt Racer with PF) but never did, then ended getting a PF servo so I the idea was simply forgotten. When this servo died (as I mentioned, it's not my first failing the exact same way; it seems a common issue with these parts) I seized the opportunity to actually implement the concept. It works surprisingly well! Grip on a hardwood floor is bad, so the tracks tend to slide a lot. 42095 is in fact built around this; friction with the ground is dynamic all the time, allowing you to drift and powerslide all about. This very context of dynamic friction also allows to control both tracks separately just to steer the skis without too much of an impact on the actual trajectory, the latter being really dictated by the skis themselves. In opposition to how a tank would behave, moving only one track, or even both in opposite directions, will in fact barely move the model at all; they are very close to each other and the skis firmly anchor the front. So difference in motor speeds will only change the steering angle; when it's ok, use both motors together and the model will follow the direction of the skis. Of course, those cause additional friction and the model itself is considerably heavier than 42095 so it's not as nimble, but the gear ratio is basically the same, so the top speed shouldn't be too much lower. And finally, it looks like an actual snowmobile when moving, where the RC stunt racer looked more fictional. tldr; I was quite disappointed when the servo died, but it ended allowing me to try something new (at least to me) that works well!

Thanks! You got it perfectly right; the differential is used in subtraction; it'll only move if both motors are not spinning at the same rate. And yes, the clutch has enough friction to steer the skis on most surfaces. I initially meant it to ride the big white fluffy carpet in my living room, but it ended not well; the model sinks into it and would only painstakingly crawl through. So now it's tuned to ride the hardwood floor and that works well. I would love to see it on the ice one day!

I like the last photo; elegant solution there!

This has been quite a journey, but I'm done rebuilding this MOC. It's really a 2.0 version; the whole chassis and tracks have been modified. It's a bit more Technic with 3 stages of reduction gears, a differential and a clutch to transform a speed delta between motors (and thus individual tracks) into steering, but consequently a bit less realistic. To make for that, I updated the design to land even closer to an actual snowmobile's shape and proportions. As before, face, seat, side panels, foot rests and the back platform all are easy-to-take-apart sub-assemblies. Video soon. As always, thanks for watching!

A lovely little machine! Looking forward to see it finished.

Thanks! I'll give this a try. But I think I'll stick with the new design for that MOC. The added complexity makes it more relevant for a TC, saves some weight (the added gears and structure are lighter than the servo) and the PF controller's buttons better match motors actions.