amorti

I did, but I'm afraid I don't remember the recipe.

Also... While I understand it's not easy to fit a differential in such a compact model, it's really uncomfortable even just pushing it around the table without one. Nevermind what happens when you add a motor. It would be better with 1WD, than that.

So, I tested the CaDA springs on my kitchen scales. They peak at about 1150g of force before they bottom out. Lego springs are around 1250g. It's not a massive difference and the suspension still doesn't work right, but it does let it return just a little higher. That and a friction pin at the top of the shock to reduce slack (it barely rotates at all anyway), and the car will sit at a sensible ride height on the shelf. At least until the springs sag. Oh, and while I'm whining: the seats are held on by a single 1*2 plate, where there's space for a 1*4 plate without any further modification. Do yourself a favour and take two if those from your spares.

If you omit the few pieces intended to stop the front axles disappearing when you put the wheels on, then it is able to return. But only a little bit, because actually it turns out that the springs are too soft. Also, there's a dark grey 20t thin bevel gear that redirects power from the prop shaft to the engine. It's in a 12:20 ratio, but it should have been done with a 12:12, because the 20t gear is too big. It hits the ground first when you bounce the front suspension. I'm not sure if it clears the crankshaft though, with 12:12. So the motto for this build, particularly when you compare it to e.g. the Lego white Porsche, is that extra functions are great... When they actually function.

This evening I finished the build. It's a nice build! However... The steering needs modifying to work as a manual system (unsupported gear due to bad construction / more likely forced by it being able to modify to RC) The front suspension feels decently weighted, but has too much friction to return. This seems to be due to excess friction in the ball joint hubs, although there are also some friction pins in there which I'll try swapping out for non-friction. The fake motor works smoothly... If you switch the half-pins for Lego, otherwise the pistons go up but don't come back down. The CaDA pins have CaDA embossed on the part, which acts as a friction ridge. You could also smooth it with a sharp blade but obviously you shouldn't have to. I won't motorise this one. I learned from the red model team style Porsche (same author M. Schlegel but I'm afraid I forgot his username here, someone please tag him if you remember it?) that driving system brick models doesn't make a whole lot of sense. However, compared to the Porsche, this one has a really solid rear axle and I wouldn't foresee it having a problem with skipping gears at all.

I finally started on the larger scale Citroen rally car last-last night. Two nights of building have seen bags #1 almost completed. It's going well so far, but... The steering wheel connection is built to be easily removable to insert a servo. It leaves the idler gear very floppy to the point that the manual steering basically doesn't work. There's an easy fix by just omitting two parts but it might not be obvious to everyone. There are 10x bags numbered 1, then bags 2&3. Phase 1 is over half the total part count. It might as well be unnumbered at that point.

Could be a fun thing to add to an LPE engine.

Vaguely interesting to see what notes somebody made themselves perhaps 30 years ago... but you could also just use the official uploaded instructions. https://www.lego.com/cdn/product-assets/product.bi.core.pdf/877169.pdf

It's kind of a live axle, using the rubber block for suspension.

Amazing shaping. Small thing - the door hinges could use the 4 axle with stop in the middle instead of a 5 axle and bush pins, to make it that bit smaller.

https://www.newelementary.com/2025/02/parts-review-sets-42206-oracle-red-bull.html?m=1

Their stuff is pretty crazy. Definitely cheat parts. @aFrInaTi0n had some parts from them and was impressed.

It is. I have some of their wheel hubs. They're 3D printed, but the print quality is very good. I made a video, but nobody really noticed it. Pretty niche, apparently. https://youtu.be/wvKhLBN7UZo?si=j1hbqf7NqiWHpQNm

Just wondering if apart from metaltechnicparts, you are aware of these guys? That frame (I don't know if they ever got past "coming soon") could solve the need for all the special parts, maybe. https://tf-engineering.at/diffcase/ I imagine they'd be willing to design a wheel hub with bearings, for the new CV joints.

In that model there was a battery pack and motor, driving a pneumatic cylinder to put air into the system. If you want to see the idea, you can (probably?) download the instructions at lego.com. Or otherwise, they used a similar system with more modern parts on the Mercedes Arocs, pretty sure you can still get the instructions for that one.